I believe there are some who still monitor the 87a yahoo group. Here are
comments I collected over the years on Fault 33:
"Hopefully, it could be just years of accumulated dirt/grim causing some
sticking to the large variable tuning cap. Is the amp sitting completely flat
and level? I heard somewhere here in the past that if there is any torsion on
the chassis then the tune and load caps may stick."
"the amp is complaining because it's not seeing the optical encoder move. That
would imply a bad motor or a jammed cap. I think it's more likely the latter.
I've had that problem once or twice, but it was intermitent. I kept restarting
the amp until it came up normally, the exercised the caps from one end of their
travel to the other, over and over. That fixed the problem. I think someone at
Alpha told me to do that."
"The cause of a Fault 33 is usually a failed LED photosensor on the TUNE
capacitor. The sensor probably needs to be replaced. "
"Depending on the age of your amp. It might be worth your while to open it up,
remove the low voltgage board and resolder all the connections. I have a
similar problem with a 15 yr old 87A. It was a cold solder joint on the low
voltage board. "
" The issue was that the grease on band switch shaft dried up and the switch
required more torque that the stepper motor could deliver. It would sometimes
switch, and sometimes not. Most of the time it would fail on start-up and set a
band switch error code. A dab of oil on the joints and exercise resolved the
problem. (Thanks Glen)"
I hope one of these helps you with your Fault 33
73 Jerry NY2KW (ex-K1JOS)
Owner of 3 Alpha 87a
-----Original Message-----
From: Amps [mailto:amps-bounces@contesting.com] On Behalf Of Dave
Sent: Sunday, August 4, 2019 2:12 PM
To: Larry Dighera <Larry@kj6yvt.com>
Cc: Alpha87a@yahoogroups.com; amps@contesting.com
Subject: Re: [Amps] Alpha 87A fault 33 when pressing TUNE DOWN
Thanks Larry. I’ll check into it. Also not sure if the Alpha 87A Yahoo group
still exists.
Good news is fault 8 is fixed with PIN diode change (rx and tx). But now fault
33. My friend bought this at a hamfest where the seller claimed it was from an
estate and it was “tested fine”. When I opened it up one TX pin diode had one
side cut right at the diode. It tested bad. 2 receive pin diodes tested bad as
well. Now -109 vdc is happy again.
Dave wo2x
73
Dave wo2x
Sent from my iPad
> On Aug 4, 2019, at 1:56 PM, Larry Dighera <Larry@kj6yvt.com> wrote:
>
>
> Hello again Dave,
>
> Several years ago I archived some of the Alpha 87A support messages
> posted to the RF Concepts web site. (See below.) Unfortunately, I
> don't find a support message that specifically addresses Fault 33.
>
> This page
> <https://web.archive.org/web/20120211083035/http://asktheham.com/node/8>
> on archive.org contains some of the messages, but is incomplete,
> unfortunately. However, as you are doubtless aware, this page
> <https://www.alpharfsystems.com/?p=1560> appears to have the old
> content.
>
> I've added Glenn W Pladsen (AE0Q) as a BCC on this message. Glenn is
> very knowledgeable about the Alpha 87A, as he has serviced them
> professionally for many years while employed by RF Concepts and their
> successors. I have found Glenn's sharp insight and decades of
> experience with ETO products very helpful on several occasions, and
> his gracious spirit of cordial assistance is very much appreciated.
> Hopefully, Glenn will assist you.
>
> Best regards,
> Larry
> WB6BBB
>
>
> -----------------------------------------------------------------------
> https://web.archive.org/web/*/http://asktheham.com/forum/*
>
>
> To: Alpha87a@yahoogroups.com
> Subject: Re: [Alpha87a] Explosive Arcing
> From: "Glenn Pladsen gm5bkc@gmail.com [Alpha87a]"
> <Alpha87a@yahoogroups.com>
> Date: Tue, 19 Aug 2014 23:47:21 -0500
> Hello Larry,
> The 87A switches the HV from low setting (about 1600vdc) to high
> (about
> 2700v) at the end of the warmup period if the HV switch is set to HI,
> which
> is where it should always be. So the arc is occurring just as the HV
> goes
> high.
>
> I would suggest doing as you said, removing the cover and blowing it
> out, and pay particular attention to the small RF choke and yellow (or
> orange) HV bypass capacitors that are in the HV path on the RF side of
> the center partition. The RF choke is just below the solenoid that
> shorts out the top of the vertical plate choke, The RF choke is about
> an inch long and positioned horizontally, one end may be too close to
> the center chassis.
> Glenn AE0Q
> RF Concepts
>
> On Tue, Aug 19, 2014 at 7:07 PM, Larry Dighera larry@kj6yvt.com
> [Alpha87a] <
> Alpha87a@yahoogroups.com> wrote:
>>
>> Hello Alpha operators and technicians,
>>
>> Shortly after I purchased my 87A a couple of years ago, a very loud arc
>> occurred just as the warm-up period expired. I feared the worst, but since
>> then it has functioned fine enabling me to work stations all over the
>> world.
>>
>> A few weeks ago I switched on the 87A in the hope of contacting a weak
>> station.
>> Waiting through the three minute warm-period was abruptly punctuated with a
>> very loud report, and the 87A and DAS shutdown (without fault code
>> indication, of course). I figured all was lost.
>>
>> Later, I again toggled the POWER ON rocker just to see what would happen.
>> To my amazement, all functioned nominally with no need to reset anything. A
>> look at the hard and soft faults showed the most recent soft fault to be 17
>> and
>> the hard fault 24. Hmmm... I'm a bit doubtful that the 87A had time to
>> record a
>> fault, but something did what appears to have been an orderly shutdown
>> without blowing a fuse of emitting smoke.
>>
>> Yesterday the arc occurred again. Because the 87A had operated okay after
>> the earlier arc, I thought that it may have been caused by some internal
>> dust
>> accumulation or insect shorting the works as a result of month's period of
>> non-operation, and I hoped the resulting arc may have blown the dust out.
>> But obviously I was wrong about that. These arcs all occurred spontaneously
>> at
>> the end of the warm-up period without any exciter input.
>>
>> So, now I'm planning on opening the 87A, and visually searching for any arc
>> indications as a clue to the cause. I'm thinking that a good blow-out with
>> compressed air may be helpful.
>>
>> <snip>
>>
> Best regards,
>> Larry
>>
> --------------------------------------------------------------------------------------------
> http://asktheham.com/node/289
> Fault 1 revisited plus some other maintenance.
> published by wo2x on Sun, 06/26/2011 - 19:05
> Forums:
> Alpha 87A Entries
> Hi All,
> Thought I would share my recent troubleshooting of an Alpha 87A amp.
> Got my friend's 1991 ETO 87A for repair for fault 1 error (soft
> fault).
> The amp has had the pin diode upgrade and resistor/diode string mods
> done at the factory several years ago. Also the choke and spark gap on
> the T/R board.
> I was following the fault 1 troubleshooting procedure and found it is
> not 100% correct.
> After following step 3 the amp was not faulting with F2 on the output
> T/R board removed. THis shows it is probably D2 and D8. This was not
> the case. D2 and D8 tested fine with the Fluke 77 (1.5 M Ohms). I
> replaced them as a precaution anyway. Still fault 1 with F2 in and no
> fault with F2 out.
> Further troubleshooting found R5 on the output T/R board open (10 M
> Ohm, 1/4 watt). I also tested D6 and D11 (which had 3.3 M Ohm
> resistors paralled to them) and found the diodes a little leaky. I
> replaced R5 , D6 and D11. No more fault 1 and back on the air!
> While I had it on the workbench I added another 200 volt zener to the
> diode string on the HV board to raise the bias voltage up to 900 volts
> instead of 700 (later 87A's have this extra diode). Also, the amp had
> intermittent fault 37 condition (bandswitch not moving. I found the
> gear from the stepper motor to bandswitch shaft tight and binding. I
> loosened the screw on the bottom of the amp and retightened after
> fixing the binding. This could have been from the amp being picked up
> by the corners instead of by the sides and torquing the chassis.
> Another precautionary measure I did was clean the pins on the Molex
> connectors which can lead to intermittent fault 24 problems.
> Amp in back on the air and working great!
> 73
> Dave wo2x
> ======================================
> http://asktheham.com/node/220
> Here is the list of upgrades possible
> published by administrator on Fri, 01/28/2011 - 13:51
> Forums:
> Alpha 87A Entries
> Hello Paul,
> Here is the list of upgrades possible. If your amp was here we would
> add a 1N5383 150v Zener diode to raise the RCV PIN diode bias voltage
> to 900vdc (yours probably has 4 Zener diodes mounted above the HV
> bleeder resistors, and is about 750vdc).
> 73 - Glenn AE0Q
> --------------------------------------------------
> 87A UPGRADE
> Note: all directions, i.e. front, rear, left, right - assume
> positioning amp with front panel facing reader HIGH VOLTAGE POWER
> SUPPLY - Verify that there are (5) (R40-R44) 220k 2-watt resistors on
> a level above the rest of the devices on the board. The ground end of
> this string should consist of zener diodes that are heat-shrink
> covered. If this construct is present, remove D15 from the board. It
> is redundant and can cause a fault 1 if it leaks. If this construct is
> not present this board needs further revision and D15 should not be
> removed. Another hint that R40-R44 are present is that R27 should
> already be missing. If R27 is not missing, don't remove D15.
> Remove 4 H.V. diodes, D1 through D4, and replace with DRX-X136
> (mono-block). See attached instructions. Double stick tape is already
> on the bottom of device. Clean board and mount diode where D1 and D3
> were.
> EPROM - Microprocessor board UPX-X108-G, U7 - Unplug the amp -
> processor is live when amp is plugged in, and the cover-microswitch
> is made, whether the amp is turned on or not turned on; even when the
> transformer is removed from the chassis.
> Front Panel has 2 screws per side and 5 along the bottom front edge of
> chassis. 2 cables between the Switch Board and the Motor Driver Board
> will have to be detached at one end or the other (note Pin 1 so you
> can put the connector back correctly). The 4-pin berg connector to
> Display board may also have to be removed depending on the cable
> routing. Now you should be clear to lay the front panel down towards
> you on its face. The processor board will be facing you on the right
> side of the inner front wall of the main chassis. Carefully remove U7
> (bottom right quadrant of board, near square processor) and install
> 108-G (pin 1 left top). Ensure all pins slide into socket. Re-install
> cable connectors and front panel.
> OUTPUT T/R MODULE - Remove the two screws on the front and left side
> edge of the perforated cover (rear-center) to give you access to the
> Output T/R board (the horizontal board under the cover). Blue 10meg
> resistor is on the Output T/R, reference designator R5. If it's
> already a ½ watt (probably black or physically bigger) (as opposed to
> ¼ watt, standard color code stripes) and you're not getting fault 1,
> you can leave it alone. (You can't successfully measure it to verify
> value in circuit. If it's open, parallel resistances will mask it.)
> The safety choke installation requires a hole in the Output T/R module
> sub chassis. The hole should be 5/32", 5/8" from top of front vertical
> wall of sub-chassis, and 1 and 3/8" in from left corner of
> sub-chassis. The washer and nut to attach the choke to the sub-
> chassis should be on the part already, "behind" the thread protector
> porcelain. The porcelain can be discarded. The safety choke is
> positioned inside the Output T/R module running north-south (thread
> end towards you, through the hole you just punched). The foam strip
> (XKX-X118) goes on top of the choke, between the choke and the output
> T/R cover. The lead on the opposite end from the threads of the device
> should have a Teflon sleeve and needs to be soldered to the RF output
> (heavy gauge wire from output T/R board to RF output connector). The
> spark gap arrestor runs from this same point (RF output) to chassis
> ground. Attach right angle solder lug HLX-X130 to Output Wattmeter
> board (Vertical on rear wall of Output T/R sub- chassis) with flat
> head screw HSS-3018. Mounting point is output connector top-right
> corner. Connector is threaded. This is the chassis ground end for the
> Spark gap arrestor. Solder one end of the arrestor to the lug you just
> attached to the Output Wattmeter board/RF output connector. Again, the
> other end should be soldered to the RF Output itself. Ensure that
> positioning of this device does not cause it to come into contact with
> the Output T/R subchassis' perforated cover. Ensure that the solder
> lug does not touch the Output toroid.
> LOW VOLTAGE POWER SUPPLY - The 100uF 25V "Fault 24 mod" cap goes on
> the LVPS, which is the vertically mounted board below the horizontal
> HVPS. Solder the negative lead of the cap to pin 12 of U4. U4 is the
> only 14 pin IC on the LVPS. Solder the positive leg of the cap to pin
> 1 of U4. Tip the amp (after you've removed the transformer) towards
> you on its face very gently. Put a cloth or something down so you
> don't scratch panel. If you lean your head over the amp the LVPS will
> now be horizontal and facing you. In addition to being the only 14 pin
> IC, U4 is the closest IC to the HVPS. Bend the leads of the cap at a
> right angle down, while holding the cap horizontal with the negative
> lead towards you. Bend the negative lead just past the body of the
> cap. Stagger the positive lead length between the body and the bend an
> additional ¼" (two IC pins). Trim the lead length of the cap so that
> the cap sits horizontally on the IC. Sooner or later your ability to
> follow instructions and craftsmanship will be judged.
> PARTS LIST
> CEX-1077 100uF, 25 V cap (LVPS board)
> DRX-X136 HV mono-block diode bridge (HVPS board)
> RFM-D106A 10 megohm, ½ watt resistor (OUTPUT T/R board)
> LCX-X105 Safety choke (OUTPUT - output t/r module)
> CGX-8010-D Spark gap Arrestor (OUTPUT - output t/r module)
> UPX-X108-G EPROM, last version before AlphaMax version 1.00AT
> (Microprocessor board)
> ====================================================================
> http://asktheham.com/node/101
> What is the best way to use the 87A AlphaMax functions?
> published by administrator on Sat, 12/04/2010 - 22:33
> Forums:
> Alpha 87A Entries
> What is the best way to use the 87A AlphaMax functions?
> When the new (since 1999) AlphaMax (Autotune) firmware is installed in
> the 87A, the TUNE and LOAD LEDs will blink to indicate what the
> AlphaMax program would do if it was enabled.
> An addendum to the 87A manual was included with AlphaMax kits thatwere
> installed in the field, or you can download a copy of the new version
> of the 87A manual (with instructions for using AlphaMax) from our web
> site: here
> You should tune up the amp with your antennas on each band/segment
> andsave the settings in USER memories. When changing bands the 87A
> first goes to the USER memory setting. If further tuning is needed it
> willmake the adjustments if the Autotune mode (AlphaMax) is enabled.
> If it is not enabled, the TUNE and/or LOAD LEDs will blink to
> indicatewhat direction those would be moved.
> If it is not in Autotune and the user settings are not at all close to
> desirable, it will fall back to factory-saved default settings (for a
> 50 ohm load) and the DEFAULT LED will light solid. If that is not
> close enough to get normal output with the current load, the amp will
> get a Fault 17.
> The Autotune function is enabled by pressing the LOAD^ and ENTER
> buttons at the same time. The DEFAULT LED will flash when Autotune is
> enabled and the amp is in operate and warmed up.
> Please note that the TUNE meter is a rough indicator to allow the amp
> to be tuned with low drive levels so that it is close to being set for
> 1500w output. Once you increase the drive and are close to 1500w out,
> fine tune by adjusting the TUNE and LOAD controls for maximum output
> at the drive level you are at. This should correspond to a dip in the
> plate current. The TUNE LED may be a number of LEDs off center to
> either side. The most useful multimeter parameter to monitor when
> transmitting is the Ip (plate current), also watching the Ig (grid
> current).
> The TUNE meter is calibrated on 20m when the amp is tuned up for 1500w
> out, with new tubes. As the tubes age, it will indicate off center a
> bit. Line voltage that is not at the nominal value for each range
> (200, 220 or 240v) may also affect the TUNE calibration.
> Since the 87A has memories that should be saved for the tuneup
> settings for each band segment, the TUNE meter isn't really as useful
> as it is with a manually tuned amp (Alpha 89/91B/99)
> ================================================================
> To: Alpha87a@yahoogroups.com, Barry J Cohen <n2bj@comcast.net>
> Subject: Re: [Alpha87a] ALPHA 87A Code 9 faults
> From: "GWP gm5bkc@gmail.com [Alpha87a]" <Alpha87a@yahoogroups.com>
> Date: Sun, 23 Oct 2016 10:04:47 -0600
> Here are the Fault 9 troubleshooting notes.
> Glenn AE0Q.
> =============================
> Fault 9 is a problem with the -109vdc PIN diode bias voltage,
> usually
> caused by the PIN diodes or sometimes the power supply.
>
> To check the PIN diodes one end must be lifted from the circuit. The
> multimeter must be in the NORMAL resistance measuring range, NOT the
> "diode check" function. You do NOT need to remove the diode from the
> chassis of the amplifier, just unsolder one of the flat, metal leads
> of the diode.
>
> The forward resistance will vary a bit depending on the voltage that
> the meter puts across the leads in the resistance measuring function.
> We usually use Fluke 77 meters, and they use 0.750vdc when measuring
> resistance, and 2.5vdc in the diode check range. I have another meter
> here that uses only 0.25vdc in the resistance function, and it reads a
> good diode ever higher (about 1.5 megohm) in forward bias, and
> 3.9 megohm in reverse bias.. Measure your meter in the normal
> resistance check function with another in the volts range to check
> the bias voltage that is used (leads connected together).
>
> The tan/yellow diodes in the T/R module are KS1001 types (the
> Recieve PIN diodes), and with one end lifted and 0.75vdc from the
> meter used to FORWARD bias it, they read 1.5 megohm. The
> REVERSE bias reading must be close to 3.9 megohm. If yours
> are reading 10k and your meter uses a similar voltage on the test
> leads, then it is leaking too much and the diode is bad.
> With the POWER OFF, remove the amplifier cover and measure the
> resistance from chassis to the tank coil, there should NOT be a short.
> If there is, that will cause a Fault 9 because the -109 goes through
> the
> two resistors mounted on the left side of the chassis. Check the
> small
> blue capacitor from bandswitch to the chassis located near the little
> circuit board on the chassis, left side. This should NOT be shorted,
> it
> should be a high resistance. If it is close to zero ohms, then there
> is
> something shorting to ground in the RF section of the amplifier. Also
> Check diode D1 (1N5404) on the Safety Choke Board, mounted on the
> chassis near the two resistors. Check ALL connections on the
> Safety Choke board.
>
> Defeat BOTH interlocks. Put the plastic cap of a Bic pen on the
> screw
> of the HV shorting spring to insulate it.
>
> Connect the 87A to AC power and turn it on. Be VERY CAREFUL, there
> is
> 3000v in the power supply and on the tubes!
>
> 1) Measure the -109vdc at either end of the large resistor mounted on
> The chassis at the left side of the RF section. If it is below 89
> volts
> when receiving, that is causing the fault, check PIN diodes. First
> remove the end of the coax cable on the little circuit board (Safety
> Choke
> Board), turn on the amp and measure -109 again. If normal (above
> -89vdc)
> there is a bad Power PIN diode (on the ABX-X220 board in the T/R
> Module).
> Reconnect coax center to Safety Choke Board.
>
> 2) Pull connector J12 (5 pin connector) at edge of Low Voltage Power
> Supply and measure for -109 on J5-2,3, if OK put back on. This
> can be difficult to do with transformer installed in amp, as an option
> go to step 3.
>
> 3) Pull connector J1 on Input T/R board (under tube deck), measure
> -109v
> there (P1-3, measure on cable connector not circuit board). If bad,
> problem is usually in LVPS. Plug in connector and measure again, if
> voltage is good at J1 but bad at Safety Choke Board, it may be a
> shorted
> Q2 (Input T/R Board). Go to step (4) before changing Q2, it is turned
> on/off by the +/-30v.
>
> 4) Measure +/- 30v on connector in T/R module, J2-2,3. It should be
> +30v when NOT keyed, and -30v when keyed.
>
> To check the PIN diodes one end must be lifted from the circuit. The
> multimeter must be in the NORMAL resistance measuring range, NOT the
> "diode check" function.
>
> The forward resistance will vary a bit depending on the voltage that
> the meter puts across the leads in the resistance measuring function.
> We usually use Fluke 77 meters, and they use 0.750vdc when measuring
> resistance, and 2.5vdc in the diode check range. I have another meter
> here that uses only 0.25vdc in the resistance function, and it reads a
> good diode ever higher (about 1.5 megohm) in forward bias, and
> 3.9 megohm in reverse bias. Measure your meter in the normal
> resistance check function with another in the volts range to check
> the bias voltage that is used (leads connected together).
>
> The tan/yellow diodes in the T/R module are KS1001 types (the
> Recieve PIN diodes), and with one end lifted and 0.75vdc from the
> meter used to FORWARD bias it, they read 1.5 megohm. The
> REVERSE bias reading must be close to 3.9 megohm. If yours
> are reading 10k and your meter uses a similar voltage on the test
> leads, then it is leaking too much and the diode is bad.
>
> There is also a KS1001 PIN diode under the tube deck that should be
> checked if the other 4 are OK.
>
> Check L1 (in the T/R Module) for any traces of an arc or burn. It
> may be under L1 (use some epoxy material for isolation).
>
>
> On Sun, Oct 23, 2016 at 7:37 AM, n2bj@comcast.net [Alpha87a] <
> Alpha87a@yahoogroups.com> wrote:
>
>>
>> I could use some input. I was on 75M a few weeks back in one of the RTTY
>> contests and all of a sudden I started getting CODE 9 Faults
>>
>> 2 weeks of troubleshooting by one of the best in the field has found that:
>>
>> "Still getting a fault. Using a 100: 1 probe I connected my oscilloscope
>> to RBIAS. It's 750 volts and should be 0 volts during receive. There's no
>> "R"
>>
>> 5 volts coming from the micro. "
>>
>> Anyone have any input that could help us out??
>>
>> Thanks
>>
>> 73
>>
>> Barry
>>
>>
>> my direct email is:
>> n2bj@comcast.net
>>
> Glenn, Merri, Hildie IJC, WV-I
> and NATCH Katie,
> NADAC Elite Versatility Award, O-TG-E, HP-O,
> MXB, MJB, OF,
> APD, APG, APR, APK,
> SPG, SPR, SPK, SPJ
> S-SSA, S-SSLA, S-STA, S-SJA, S-IAA,
> http://www.hoopsandjumps.com/
> http://funagility.webs.com/
> --------------------------------------------------------------------------
> http://asktheham.com/node/64
> Alpha 87A Checking PIN Diodes
> published by administrator on Sat, 12/04/2010 - 21:09
> Forums:
> Alpha 87A Entries
> To check the PIN diodes one end must be lifted from the circuit. The
> multimeter must be in the NORMAL resistance measuring range, NOT the
> "diode check" function.
> The forward resistance will vary a bit depending on the voltage that
> the meter puts across the leads in the resistance measuring function.
> We usually use Fluke 77 meters, and they use 0.750vdc when measuring
> resistance, and 2.5vdc in the diode check range. I have another
> meter here that uses only 0.25vdc in the resistance function, and it
> reads a good diode ever higher (about 1.5 megohm) in forward bias.
> Measure your meter in the normal resistance check function with
> another in the volts range to check the bias voltage that is used
> (leads connected together).
> The tan/yellow diodes are KS1001 types, and with one end lifted and
> .75vdc from the meter used to forward bias it, they read 1.5 megohm.
> If yours are reading 10k and your meter uses a similar voltage on the
> test leads, then it is leaking too much.
> Log in or register to post comments
> K4VUD
> Sat, 01/29/2011 - 01:44
> Permalink
> Fault 9 and PIN diodes
> I have had Fault 9 on TWO different 87a amps over the past 20 years.
> One went back to factory THREE TIMES and the other Twice. The problem
> happened again after the "fix" and the one I have now is stuck again
> on Fault 9.
> This seems to be a design flaw in this amp and the only fix appears to
> replace the failed parts at the factory price of about $350, plus
> shipping. There is a factory add-on that promises to retard RF from
> another big amp operating near the 87a from coming into the 87a and
> blowing some of these parts that give Fault 9, but I put all that
> stuff in and still have Fault 9 right now.
> I think I will just sell this un-fixable thing and get something
> better.
> =========================================================
> http://asktheham.com/node/62
> Alpha 87A/89 Amplifiers and AM
> published by administrator on Sat, 12/04/2010 - 21:09
> Forums:
> Alpha 87A Entries
> To run AM with an amplifier, you should tune it up first at the full
> power level of the AM signal that is 100% modulated. If this is going
> to be 1500w, the carrier power with NO modulation would then be set to
> 375w without retuning the amp (set it with the drive control on the
> transceiver in AM mode).
> The ALPHA 87A uses a pair of Eimac 3CX800A7 tubes, grid driven in
> Class AB2.
> Carrier-only output is limited by the facts that
> (1) the amplifier must remain linear on 100% modulation peaks, which
> are 4x the carrier power,
>
> (2) efficiency of an AB or B linear amplifier at 25% of design power
> output (or more to the point, at 25% of the peak output power for
> which it's tuned up) is typically about 30% ... it pretty much runs
> Class A at that power level, and (3) consequently, power supply
> loading and tube plate dissipation are the limiting factors under
> carrier conditions (without modulation).
> Let's assume linear operation with 100% A3 amplitude modulation,
> yielding the 87A's nominal rated PEP output of 1.5 kW. By definition,
> carrier output must be 375 watts. Assuming ~30% plate efficiency under
> carrier-only conditions, d-c plate input must be in the vicinity of
> 375/0.3 = 1250 watts. Most of the difference, or 1250-375 = 875W, is
> plate dissipation.
> As it happens, the 87A can comfortably handle both of these
> parameters, although one definitely should use a good, high-output
> "Muffin" type auxiliary cooling fan to keep the tubes and cabinet cool
> under continuous duty conditions.
> ============================================
> http://asktheham.com/node/61
> Alpha 87A Wattmeter Scaling
> published by administrator on Sat, 12/04/2010 - 21:08
> Forums:
> Alpha 87A Entries
> 1) Connect PC to serial port with a modem program communicating with
> the amplifier.
> 2) With the 87A in STANDBY, transmit through the amplifier with 100 w
> steady carrier (use CW or RTTY) from the radio to a dummy load or
> antenna with low SWR.
>
> 3) On the PC, type EXT ON.
> 4) On the PC, type GPIO (radio still transmitting 100w). This command
> reports Grid current, Plate current, Input power, and Output power
> each time it is typed. It should be showing about 100w input and
> output. If one of those is not reading correctly, either the wattmeter
> diodes are damaged or it just needs to be rescaled.
> Rescaling the wattmeter calibration involves changing data in the
> microprocessor tables. This involves reading and changing data at
> certain memory locations, the data is in hexadecimal format (base 16).
> Instructions are below.
> The Input Power scaling factor is stored in addresses B79B and B79C.
> The Output Power scaling factor is stored in addresses B79D and B79E.
> 1) Read the hex values stored in those locations (write them down!!!):
> type
> EXT ON(ENTER)
> DM B79B(ENTER) (record the first 4 pairs of hex numbers, left to
> right)
> The data in B79B is the first pair, the data in B79C is the 2nd pair,
> data in B79D is 3rd pair, and data in B79E is 4th pair of hex numbers.
> 2) To raise the INput power reading, increase the number in B79C
> (lower the number to lower power reading):
> W B79C xx(ENTER) xx = original hex number plus 16 (for example, 8E
> changes to 9E, 9E would be changed to AE, etc) Finer increments result
> from changing the last digit, for more coarse increments you could
> change the last digit in B79B by one. Change scaling up or down as
> needed.
> After every change, transmit 100w through amp (in standby) and type
> GPIO command to read wattmeters.
> 3) To raise the OUTput power reading, increase the number in B79E.
> W B79E xx(ENTER) xx = original hex number plus 16
> ====================================================
> http://asktheham.com/node/60
> Alpha 87A noise on receive
> published by administrator on Sat, 12/04/2010 - 21:08
> Forums:
> Alpha 87A Entries
> When this occurs move the tune cap out of resonance in RX and the amp
> in operate and no drive. If the noise changes it is the TX diodes. If
> it does not it is the RX diodes.
> ===============================
> http://asktheham.com/node/59
> Alpha 87A HI/LO switch
> published by administrator on Sat, 12/04/2010 - 21:07
> Forums:
> Alpha 87A Entries
> You should always use the HI setting of the HV switch. The low HV is
> for some overseas customers that only have an 800-1000w output limit
> (Japan and some Europeans). The lower plate voltage forces the plate
> current to be higher, which limits their maximum output. In some
> countries they are required to show this in operation to the licensing
> authorities, etc. Control the output power by lowering the drive to
> the amplifier.
> ==============================
> http://asktheham.com/node/58
> Alpha 87A Frequency Detect Adjustment
> published by administrator on Sat, 12/04/2010 - 21:07
> Forums:
> Alpha 87A Entries
> Alpha 87A Frequency Detect Adjustment:
> The pot in the bottom of the 87A is to be adjusted as follows.
> 1. Place the 87A on it's right side.
> 2. Remove the bottom cover under the tubes.
> 3. Place the transceiver on 28mhz and adjust the power output to 5
> watts.
> 4. Place the amplifier in the 160 meters position.
> 5. Put the pot in the full clockwise position to start.
> 6. Key the radio and adjust the pot counter clockwise until the
> amplifier changes bands then stop there.
> 7. Replace the covers and place the amp back flat on the table.
>
> If the amp is still having problems changing frequency than the amp
> needs to be repaired. The problem is most likely on the frequency
> counter PCB and will need additional trouble shooting.
> =====================
> http://asktheham.com/node/57
> Alpha 87A Intermittent Frequency Detect
> published by administrator on Sat, 12/04/2010 - 21:06
> Forums:
> Alpha 87A Entries
> Intermittent Frequency Detect in Alpha 87A
> 1) Unplug amplifier from the 220vac and take apart the plug. Make sure
> the screws holding the wires are tight, they sometimes get loose. When
> you unplug the amplifier from the power, you are also resetting the
> microprocessor. It has 5v whenever the amp is plugged in, even when it
> is turned off. Resetting the microprocessor might fix it. Plug in the
> amp and turn it on. Test to see if it now works OK.
> 2) If it is still not working correctly, you will need to unplug it
> from the power again. If you have bolted the big power transformer
> into the chassis, tip the amplfier up so that it is standing on it's
> right-hand side. If the transformer is not bolted to the chassis, you
> will need to take off the cover and remove the transformer before
> setting the amp on it's right side, or put in the bolts to hold in the
> transformer now.
> 3) Remove the plate on the bottom of the chassis that is under the
> tube deck (where the tubes plug in). When you look into the opening,
> there is a white 8-pin connector in the upper right-hand corner near
> the edge of the opening. This connector carries the frequency signal
> to the microprocessor. Pull the connector off and push it back on,
> making sure that it is on all the way. In the upper left-hand corner
> there is a short jumper between two circuit boards. It should go into
> holes in the two boards that are
> labeled RF FWD. Check very closely and make sure that it is in the
> correct holes. There is one hole labeled GND and the wire should NOT
> be in this hole. Near the middle of the top circuit board, to the left
> of the white 8-pin connector, there is a small variable resistor
> (potentiometer). This adjusts the sensitivity of the frequency
> measuring circuit. The slot in the potentiometer should be about in
> the middle, pointing almost straight up. Note the position of the
> slot, then use a small screwdriver to turn the adjustment from one end
> to the other a few times. The potentiometer may have dirty contacts
> and this will clean them. Set the adjustment back where it was when
> you started. Replace the metal plate and put the amplifier back to
> it's normal position on the table.
> 4) There is one more cable that you can try to reseat. It is the other
> end of the frequency signal to the microprocessor. With the top cover
> removed, it is a long red connector that you can see at the top
> right-hand part of the amp just behind the front panel (there are two
> long red connectors together). This plugs into the control board that
> has the microprocessor. Carefully pull the connector off and plug it
> back on, making sure that it is pushed on all the way.
> Replace the top cover and test the amplifier again.
> =======================
> http://asktheham.com/node/56
> Alpha 87A Fault 99
> published by administrator on Sat, 12/04/2010 - 21:06
> Forums:
> Alpha 87A Entries
> Please unplug the 87A for 2 minutes and then plug it back in to the
> 240v. This will reset the microprocessor and can sometimes correct
> erratic operation (possibly caused by stray RF), although it will NOT
> clear hard faults or remove them from the fault log.
>
> The 87A should 'talk' to the PC anytime it is plugged into mains
> power, even when it is turned off. This is the best troubleshooting
> tool that we have.
> Below are some notes about the 87A fault protection and instructions
> for clearing the fault log.
> IMPORTANT !!!!!
> Please remember that when the 87A gets a hard fault and then the power
> is turned back on, it will report the fault for 30 seconds and then
> clear automatically. You must not turn off the power before the fault
> clears (about 30 seconds), or it will log another hard fault the next
> time the power is turned on. Also remember that six of the SAME hard
> fault shutdowns over ANY period of time (with no other kind of Hard
> fault) will then put the 87A in Fault 99 which locks it up. This
> function was put in the amplifier to prevent any further damage if
> operation was attempted after a failure had occurred. If you keep
> turning off the power before a hard fault has cleared, and this causes
> 6 of the same hard faults to be entered in the fault log, the 87A will
> then go into Fault 99 and will not turn on. Also, if the 87A is turned
> on 6 times when it keeps shutting down immediately because of a hard
> fault, it will go into Fault 99.
> Here are two sets of instructions, one for setting up HyperTerm that
> is built into most versions of Windows for the communications, and the
> second set is for clearing the Fault 99.
> To find out what the status of the amplifier is, you need to use a
> modem communications program. Windows 95/98 comes with one called
> HyperTerminal. It is usually located in the ACCESSORIES program group.
> On Win98 it may not have been installed as the default and you can
> install it by inserting the Win98 CD and selecting it in the "Add
> Programs, Communications" menu.
> When you click on HyperTerminal from the START, PROGRAMS, ACCESSORIES
> menu it will open a program group on the screen.
> Click on HYPERTRM.EXE and it will open a window for a new connection.
> Give it a name, and in the next window select the "Connect Using:
> Direct to COMx" pulldown menu (in the bottom of the box on my version
> of Win95); select the Com port you will use. If the COM port you
> select is available it will open another box called "COMx Properties".
> Going down the list, select Bps-4800, Data
> bits-8, Parity-NONE, Stop bits-1, Flow control-NONE. Click OK to close
> the window. Now pull down the FILE menu and click PROPERTIES. Click
> the SETTING tab and then click ASCII SETUP at the bottom of the
> window. Click the box for "Echo typed characters locally" (it could
> have a check in the box). Click OK to close both windows.
> Plug in the amp (power off) and it should be communicating with the
> computer. Type VER and press the Enter key. The 87A should respond
> with the firmware version number.
> ATTENTION ATTENTION !!!!!!!!!!!!!!
> If you see garble (or nothing) you will need to remove pin 22 of the
> 25-pin end of the cable (the 87A end). It is used to set the baudrate
> of the amplifier. Page 19 of the 87A manual has a complete explanation
> of the communications connections.
> When it is communicating OK, type SF and HF to display the Soft Fault
> and Hard Fault logs (press Enter key after each command). Save the
> result of those commands.
> A list of more commands is on pages 20 and 21 of the 87A manual (pages
> 40 and 41 in 87A Manual Rev 1.0)
> To clear a Fault 99 on an Alpha 87A amplifier with a PC connected:
> Type in the following commands and enter them for each new line.
> EXT ON
> W B71A FF
> W B71B FF
> W B71C FF
> W B71D FF
> W B71E FF
> W B71F FF
> W B720 FF
> W B721 FF
> W B724 FF
> W B725 FF
> W B726 FF
> W B727 FF
> W B728 FF
> W B729 FF
> W B72A FF
> W B72B FF
> W B72C 0C
> W B72D B5
> W B7E0 FF
> W B7E1 FF
> W B7E2 FF
> W B7E3 FF
> W B7E4 FF
> W B7E5 FF
> W B7E6 FF
> W B7E7 FF
> HF
> SF
> When you type HF and SF they should show all 00. Unplug the 87A from
> the mains power for 30 seconds. This resets the microprocessor. The
> amplifier is now ready for normal use
> ================================
> http://asktheham.com/node/55
> Alpha 87A Fault 8
> published by administrator on Sat, 12/04/2010 - 21:05
> Forums:
> Alpha 87A Entries
> THIS IS VERY, VERY DANGEROUS. IF YOU DON'T HAVE EXPERIENCE WORKING
> AROUND HIGH VOLTAGE, DO NOT - WE REPEAT, DO NOT DO THIS. CALL THE
> COMPANY FOR AN RMA NUMBER, PACK THE AMPLIFIER IN A BOX, AND RETURN IT
> TO US FOR SERVICE. THERE IS A 3,000 VOLT POWER SUPPLY IN THE AMPLIFIER
> THAT CAN EASILY KILL YOU. THERE ARE MULTIPLE POINTS IN THIS AMPLIFIER
> THAT GENERATE LETHAL VOLTAGES. WE REPEAT - UNLESS YOU KNOW EXACTLY
> WHAT YOU ARE DOING WITH THIS, AND YOU'VE WORKED AROUND HIGH VOLTAGES
> BEFORE, DO NOT OPEN THE CASE AND DEFEAT ANY INTERLOCK EVER. (EVER)
> Fault 8 is a problem with the -109vdc PIN diode bias voltage, usually
> caused by the PIN diodes or sometimes the power supply.
> With the POWER OFF, remove the amplifier cover and measure the
> resistance from chassis to the tank coil, there should NOT be a short.
> If there is, that will cause a Fault 8 because the -109 goes through
> the two resistors mounted on the left side of the chassis. Check the
> small blue capacitor from bandswitch to the chassis located near the
> little circuit board on the chassis, left side. This should NOT be
> shorted, it should be a high resistance. If it is close to zero ohms,
> then there is something shorting to ground in the RF section of the
> amplifier. Also Check diode D1 (1N5404) on the Safety Choke Board,
> mounted on the chassis near the two resistors.
> Defeat BOTH interlocks. Put the plastic cap of a Bic pen on the screw
> of the HV shorting spring to insulate it.
> Connect the 87A to AC power and turn it on. Be VERY CAREFUL, there is
> 3000v in the power supply and on the tubes!
> 1) Measure the -109vdc at either end of the large resistor mounted on
> the chassis at the left side of the RF section. If it is below 89
> volts when receiving, that is causing the fault, check PIN diodes.
> First remove the end of the coax cable on the little circuit board
> (Safety Choke Board), turn on the amp and measure -109 again. If
> normal (above -89vdc) there is a bad Power PIN diode (on the ABX-X220
> board in the T/R Module). Reconnect coax center to Safety Choke Board.
> 2) Pull connector J12 (5 pin connector) at edge of Low Voltage Power
> Supply and measure for -109 on J5-2,3, if OK put back on. This can be
> difficult to do with transformer installed in amp, as an option go to
> step 3.
> 3) Pull connector J1 on Input T/R board (under tube deck), measure
> -109v there (P1-3, measure on cable connector not circuit board). If
> bad, problem is usually in LVPS. Plug in connector and measure again,
> if voltage is good at J1 but bad at Safety Choke Board, it may be a
> shorted Q2 (Input T/R Board). Go to step (4) before changing Q2, it is
> turned on/off by the +/-30v.
> 4) Measure +/- 30v on connector in T/R module, J2-2,3. It should be
> +30v when NOT keyed, and -30v when keyed.
> To check the PIN diodes one end must be lifted from the circuit. The
> multimeter must be in the NORMAL resistance measuring range, NOT the
> "diode check" function.
> The forward resistance will vary a bit depending on the voltage that
> the meter puts across the leads in the resistance measuring function.
> We usually use Fluke 77 meters, and they use 0.750vdc when measuring
> resistance, and 2.5vdc in the diode check range. I have another meter
> here that uses only 0.25vdc in the resistance function, and it reads a
> good diode ever higher (about 1.5 megohm) in forward bias. Measure
> your meter in the normal resistance check function with another in the
> volts range to check the bias voltage that is used (leads connected
> together).
> The tan/yellow diodes in the T/R module are KS1001 types, and with one
> end lifted and 0.75vdc from the meter used to forward bias it, they
> read 1.5 megohm. If yours are reading 10k and your meter uses a
> similar voltage on the test leads, then it is leaking too much.
>
> There is also a KS1001 PIN diode under the tube deck that should be
> checked if the other 4 are OK.
> =======================
> http://asktheham.com/node/54
> Alpha 87A Fault 37
> published by administrator on Sat, 12/04/2010 - 21:04
> Forums:
> Alpha 87A Entries
> Fault 37 means that either the bandswitch is just momentarily stuck,
> or there has been a failure on the motor-driver board.
> You can try manually moving the bandswitch to loosen it up. Unplug the
> amp, remove the cover, and turn the white gear on the left side a half
> inch or so. Put cover back on and turn on amp to see if that has
> worked (or defeat BOTH interlocks and turn on with cover off).
> If it stays on, cycle the bandswitch 5 or 6 times by manually
> selecting first 10m, then 160m.
> If the amp is still getting an immediate Fault 37, we will have to
> repair it here, we can give you a Return Authorization number and
> shipping instructions.
> ===================
> http://asktheham.com/node/53
> Alpha 87A Fault 24
> published by administrator on Sat, 12/04/2010 - 21:04
> Forums:
> Alpha 87A Entries
>
> 1) Do you notice that the amp is always on the same band when this
> happens?
> 2) Check the AC mains voltage and what you have the 87A set for. You
> must measure the AC voltage with a digital multimeter, the actual
> voltage must be within +/- 10 vac of what the amp is set for. Your
> line voltage may vary quite a bit from one season to another.
> 3) Unplug the amp and remove the cover. On the AC voltage selection
> terminal strip, the heavy white wire goes on the first of 4 terminals
> and does not move. For 240vac, the other heavy white wire should be on
> the 4th screw terminal (2 empty screws between them).
> 4) Visually check that connector J3 on the right rear edge of the Low
> Voltage Power Supply (LVPS) is plugged onto the pins on the LVPS
> circuit board. This connector is just below the horizontal circuit
> board, and next to the white supporting post. It can be pulled loose
> when installing the transformer. Look at the red connectors in the
> same area of the LVPS to be sure they are all plugged in.
> 5) Measure from the gold-colored resistor on the chassis of the amp
> (left side of RF section) to ground to see if it is shorted to the
> chassis. You should measure 18 ohms across the two parallel resistors.
> The resistance to the chassis on either end should be more than 100
> kohms. If it is too low it will drag down the -109vdc.
> 6) Look carefully at the monoblock HV bridge rectifier on the HV
> circuit board (about 1.5" square, black, 4 leads coming out of it),
> inspect it to be sure there are no burned areas or signs of arcing. If
> it is mounted under the HV circuit board, it may have fallen off the
> board and be shorting to something.
> 7) Check the three resistors R15, R16, R17 (all 1 megohm, measure
> about 667k in the circuit), R20 (measures 3.8k to ground) and R38 (1
> kohm), all located on the left side of the HV circuit board. This is
> the HV monitoring circuit and can cause Fault 24 even if the HV is
> good.
> 8) Check transistors and regulator on the right side of the HV circuit
> board, be sure they are not bent or broken.
> Log in or register to post comments
> mollyh
> Thu, 12/09/2010 - 02:32
> Permalink
> Benign causes of Fault 24
> A spurious Fault 24 can be caused when your 87A has been left
> connected to the mains supply for an extended period of time. Whenever
> the 87A is connected to the mains supply, the micro processor is
> running - a simple brown-out can cause the processor to partially
> reset and generate a fault 24. Although this fault is difficult to
> diagnose and frequently amps with this problem have to return to us
> for repair - about 30% of the time simply unplugging the amp from the
> line voltage to reset it and then letting it warm up normally will
> cure the problem.
> Please also pay particular attention to point 7) above - if the
> metering resistors have failed you'll get a Fault 24 that is really
> easy to diagnose and repair - those resistors look like a string of
> hot dogs.....
> Log in or register to post comments
> N6YW
> Thu, 07/19/2012 - 20:37
> Permalink
> Fault 24
> I have thoroughly gone through my 87A problem child, checked every
> possible known issue and all checks out, including my line voltage
> which never fluctuates more than a few volts during measurement. The
> branch circuit to my shack runs about 30 ft using #10 THHN. During
> operation, under load, my mains voltage drop is only 2 volts compared
> to the amp being off.
> The date codes on my filter capacitors show them all to be late 2001,
> so while I was inspecting the LVPS board, I went ahead and replaced
> the fault 24 cap on IC4. We'll see if that helps or not.
> Otherwise, my head scratching starts all over again. Meanwhile, the
> love/hate relationship with my 87A continues.
> 73 N6YW
> ============================
> http://asktheham.com/node/52
> Alpha 87A Fault 22
> published by administrator on Sat, 12/04/2010 - 21:04
> Forums:
> Alpha 87A Entries
> If the 87A reports a Fault 22, it is usually caused by a blown
> step-start fuse (at the center of the amp next to the AC Voltage
> terminal strip), or can indicate that the 36v power supply fuse is
> blown.
> The 36v fuse is on the Low Voltage Power Supply (LVPS). The fuse is
> marked 125v/2A, it is called the 36v fuse because it is in the 36v
> circuit. The LVPS is under the HV Power Supply, its circuit board is
> vertically mounted.
> This is a small cartridge fuse that plugs into a socket (usually
> white). This can be seen from the right-hand side of the amplifier,
> under the High Voltage board 1/5 in from the top edge and 3/4 in from
> the right-hand edge of the LVPS board. It may measure a few ohms when
> good, but should be less than 10 ohms.
> Another cause of the amp shutting down can be a shorted tube. You can
> test that by either removing the tubes, or by disconnecting the red HV
> lead from the left-rear corner of the HV power supply board. It will
> still get a fault, but should not be a hard fault.
> ====================
> http://asktheham.com/node/51
> Alpha 87A Fault 20 or 18
> published by administrator on Sat, 12/04/2010 - 21:03
> Forums:
> Alpha 87A Entries
> We have found that reseating the connectors on circuit boards may stop
> the erroneous filament current readings.
> Stand the 87A on the right-hand side and remove the plate under the
> tube-deck. Unplug and carefully reconnect the plugs inside the tube
> deck. Also reseat the orange connector on the LVPS (Low Voltage Power
> Supply) directly in front of the power transformer, and just above the
> bottom orange connector that is on one of the transformer cables. Use
> Caig DeOxit contact cleaner (available at Radio Shack) on those
> connectors to ensure a better contact.
> Reseat the two large red connectors on the top edge of the control
> board. They are accessable through the slot in the top-right side of
> the front sub-chassis (behind the LED bargraph displays).
> The Fault 20 may indicate a bad tube or a metering resistor that has
> aged and changed value. With a computer connected to the 87A serial
> port you can use the following commands to see what the filament
> current is (they are always followed by the ENTER key):
>
> Type EXT ON (ENTER) , this puts the amp in the 'factory mode' and will
> let it accept the next command.
> Type ADS FIL (ENTER) numerous times and record the readings. This will
> give you the filament current. It will read some filament current even
> when the 87A is turned off, this is normal and is not a 'real' number
> because the tubes are turned off. The fault limit is 4.0 amps.
> When you are done testing, type EXT OFF to turn off the 'factory mode'
> so that no wrong commands will accidentally be written to the
> microprocessor.
> Once you have completed this process, email the factory with your
> results and for further instructions on possibly changing the filament
> current limits in the amplifier EEPROM
> Log in or register to post comments
> mollyh
> Thu, 12/09/2010 - 02:23
> Permalink
> Fault 20 on the 87A
> Note that although the formal resolution above also talks about a
> possible tube problem - in my 10+ years working directly with Alpha
> amps I have yet to see a Fault 20 that is caused by a bad tube.
> Cleaning the connectors as described above will give you anywhere from
> 6 months to 2 or 3 years more 20-free operating. Eventually you will
> need to get the connectors changed......
> =====================
> http://asktheham.com/node/50
> Alpha 87A Fault 17 and GPIO test
> published by administrator on Sat, 12/04/2010 - 21:03
> Forums:
>
> Alpha 87A Entries
>
> The Fault 17 is a TUNE, or GAIN, fault. If it is happening on all
> bands, it is possibly because of a failed diode (1N5711) in one of the
> wattmeters. There are Input and Output wattmeters.
> Here are some tests.
> 1) Connect PC to serial port with a modem program communicating with
> the amplifier.
> 2) With the 87A in STANDBY, transmit through the amplifier with 100 w
> from the radio to a dummy load (or antenna with low SWR).
> 3) On the PC, type EXT ON.
> 4) On the PC, type GPIO (radio still transmitting 100w). This command
> reports Grid current, Plate current, Input power, and Output power
> each time it is typed. It should be showing about 100w input and about
> 100w output. If one of those is not reading correctly, that indicates
> the wattmeter diodes are damaged.
> -----------------------------------
> To: ve6jy.1@gmail.com
> Subject: Re: [Amps] Alpha fault 17
> From: K2CB <k2cb@comcast.net>
> Date: Fri, 9 Dec 2016 00:53:30 -0500
> Cc: Amps@contesting.com
> Do a search of the 87A Yahoo group regarding the large L1 choke coil
> on the RF output wattmeter / pin diode / bypass relay module near the
> rear antenna jack. Don't quote me on the exact part designation, as I
> am not at my desk top at the moment, but it is the large green one on
> that board.
> Remove the four screws and shield cover. You will see a large green
> wire wound choke coil. Alpha placed a piece of black foam between the
> coil and circuit board as an insulator.
> This material is breaking down over time, and causing the coil to arc
> over to the ground plane of the circuit board. It will get worse over
> time, and the fault 17 will occur with less and less rf output power
> as time goes on.
> Remove the choke from the board, remove all the old foam pad, clean
> off any carbon on the circuit board from the arcing , and install a
> replacement piece of insulation material. I used some thin black
> plastic. Then reinstall the choke coil.
> If you must remove the entire circuit board, be especially careful
> with the pin diode mounting and associated insulators. They are
> somewhat fragile.
> If you like, I can send you some pictures I took of the last 87A I
> repaired with the same problem. The photos are on my desktop. I can
> send them tomorrow when I get back to my office.
> FYI - Credit is due to Brad from Alpha (or whatever their name is this
> year!) for originally suggesting this as a possible Fault 17 cause.
> Eric
> K2CB
>
> ---------------------------------------
> have you noticed whether the Fault 17 occurs when
> changing bands? If so, here is another note I found in my files from
> Glenn
> at Alpha years ago where a misalignment of the frequency detect can
> lead to
> Fault 17:
>
> 73 es HH
> Jerry NY2KW
>
> ******************************************************
> Alpha 87A Frequency Detect Adjustment:
> The pot in the bottom of the 87A is to be adjusted as follows.
>
> 1. Place the 87A on it's right side.
> 2. Remove the bottom cover under the tubes.
> 3. Place the transceiver on 28mhz and adjust the power output to 5
> watts.
> 4. Place the amplifier in the 160 meters position.
> 5. Put the pot in the full clockwise position to start.
> 6. Key the radio and adjust the pot counter clockwise until the
> amplifier
> changes bands then stop there.
> 7. Replace the covers and place the amp back flat on the table.
> *******************************************************
> From: "Dick Green WC1M" <wc1m73@gmail.com>
> Date: Fri, 9 Dec 2016 12:48:08 -0500
> Cc: Amps@contesting.com
>
> Some additional points:
>
> - You may not be able to see evidence of arcing until you remove the
> choke.
> - You may need to replace (rewind) the coil. Just count the turns and
> use
> the same gauge/type of wire
> - When my choke coil started arcing, I didn't get fault 17. I got
> faults 8
> and 9 (and 1, I think).
> - This was evidence that the arcing damaged one of the transmit PIN
> diodes,
> which I had to replace.
>
> Don't use the amp until you attend to the choke coil. You don't want
> to risk
> damage to the PIN diodes, which are expensive.
>
> 73, Dick WC1M
> =======================
> http://asktheham.com/node/49
> Alpha 87A Fault 11
> published by administrator on Sat, 12/04/2010 - 21:02
> Forums:
>
> Alpha 87A Entries
>
> Fault 11 usually means that one of the variable capacitors (TUNE or
> LOAD) is shorted, or the PIN diode T-bias voltage is low.
>
> If it faults on all bands, check the 1/4 amp fuse in the Output T/R
> Module. It is a small clear and white fuse that plugs into a white
> socket on the circuit board. Also look for any other burned parts in
> the T/R module whle checking
> the fuse. Look for the leads of PIN diodes recently changed that may
> be touching the chassis?
>
> Fault 11 is fairly unusual and we don't have any set guidelines for
> troubleshooting that, other than tracking down the T-bias circuit. I
> can give you a Return Authorization Number to send here for repair.
> ==============================
> http://asktheham.com/node/48
> Alpha 87A Fault 1 Troubleshooting
> published by administrator on Sat, 12/04/2010 - 21:02
> Forums:
>
> Alpha 87A Entries
>
> THIS IS VERY, VERY DANGEROUS. IF YOU DON'T HAVE EXPERIENCE WORKING
> AROUND HIGH VOLTAGE, DO NOT - WE REPEAT, DO NOT DO THIS. CALL THE
> COMPANY FOR AN RMA NUMBER, PACK THE AMPLIFIER IN A BOX, AND RETURN IT
> TO US FOR SERVICE. THERE IS A 3,000 VOLT POWER SUPPLY IN THE AMPLIFIER
> THAT CAN EASILY KILL YOU. THERE ARE MULTIPLE POINTS IN THIS AMPLIFIER
> THAT GENERATE LETHAL VOLTAGES. WE REPEAT - UNLESS YOU KNOW EXACTLY
> WHAT YOU ARE DOING WITH THIS, AND YOU'VE WORKED AROUND HIGH VOLTAGES
> BEFORE, DO NOT OPEN THE CASE AND DEFEAT ANY INTERLOCK EVER. (EVER)
>
> Alpha 87A Fault 1 Troubleshooting Instructions
>
> Here are troubleshooting instructions for a Fault 1. Be sure to defeat
> both interlocks when turning on the amplifier with the cover off, the
> microswitch and the HV shorting crowbar at the center of the amp! Slip
> the cap from a Bic-type pen over the crowbar screw to insulate it, the
> shorting spring will hold it in place.
>
> These notes apply to firmware v1.08G or 1.00AT, earlier versions may
> not turn on R-bias during warmup.
>
> 1) The receive bias switches when you go from STBY (700 to 900v) to
> OPERATE (less than 1v). When the amp is in OPERATE and keyed, it will
> also be 700v to 900v. Measure at the R BIAS (or R with a line over it)
> terminal on right rear corner of HV Power Supply board.
>
> 2) If the voltage is always lower than 700v, turn off the amplifier,
> remove the connector at R BIAS on the HV Power Supply, and turn the
> 87A back on. If R BIAS is still low the problem is on the HV board,
> either an open resistor at R40-R43 (each 220k/2w or two 470K/1w in
> parallel) or
> a defective Zener diode at D18-D22. Older 87A HV Power Supply boards
> do not have those components on the circuit board, they will be wired
> and suspended above the 2 watt HV bleeder resistors. If R BIAS is 700v
> to 900v with the connector removed and the amplifier turned on, turn
> off the amplifier, put connector back on and proceed to next step.
>
> 3) Remove fuse F2 on the ABX-X180 board (inside the output T/R box)
> and then check 87A again. If it does NOT fault and R-BIAS voltage is
> between 700 and 850 volts, replace D2 and D8. R-BIAS can be measured
> at the back-right corner of the High Voltage Power Supply board, on a
> terminal labeled NOT-R (R with a line over it), or on J4 of the
> ABX-X180 board.
>
> 4) If it DOES fault with F2 removed, lift D6 and D11 diode chain on
> the ABX-X180 board. If the 87A does not fail and R BIAS voltage is
> between 700 and 900 volts, replace D6 and D11.
>
> 5) Lift R5 on the ABX-X180 board and measure to make sure it is not
> open. R5 is located below the large 2.5 mH 'safety choke' mounted on
> the front edge of the T/R compartment.
>
> Note: When replacing the diodes, be careful not to have the leads
> protruding too far below the circuit board, it is possible for them to
> touch the chassis (gnd).
>
> 6) Replace D16 on the HV P/S board, ABX-X177. It can leak and slow
> down the bias switching.
>
> On the HV POWER SUPPLY BOARD drawing #SXX-X161 (in the complete set of
> 87A schematics) transistors Q3 and Q4 (schematic Rev I) may cause the
> bias to stop switching (Q4 on schematic Rev K). They may also be the
> problem if the bias does not switch at all.
> ===============================
> http://asktheham.com/node/47
> Alpha 87A Communications
> published by administrator on Sat, 12/04/2010 - 21:01
> Forums:
>
> Alpha 87A Entries
>
> Please unplug the 87A for 1 minute and then plug it back in to the
> 240v. This will reset the microprocessor and can sometimes correct
> erratic operation (possibly caused by stray RF), although it will NOT
> clear hard faults or remove them from the fault log.
>
> The 87A should 'talk' to the PC anytime it is plugged into mains
> power, even when it is turned off. This is the best troubleshooting
> tool that we have. Note that the 20A fuses must be good.
>
> Below are some notes about the 87A fault protection.
>
> Please remember that when the 87A gets a hard fault and then the power
> is turned back on, it will report the fault for 30 seconds and then
> clear automatically. You must not turn off the power before the fault
> clears (about 30 seconds), or it will log another hard fault the next
> time the power is turned on. Also remember that six of the SAME hard
> fault shutdowns over ANY period of time (with no other kind of Hard
> fault) will then put the 87A in Fault 99 which locks it up. This
> function was put in the amplifier to prevent any further damage if
> operation was attempted after a failure had occurred.
>
> If you keep turning off the power before a hard fault has cleared, and
> this causes 6 of the same hard faults to be entered in the fault log,
> the 87A will then go into Fault 99 and will not turn on. Also, if the
> 87A is turned on 6 times when it keeps shutting down immediately
> because of a hard fault, it will go into Fault 99.
>
> Once the 87A is in Fault 99 condition, each time the ON switch is
> pressed it logs another Fault 99. After 8 times, the original hard
> fault will have been shifted out of the fault log, it will only show
> 99 and not the fault that caused the original problem.
>
> Here are instructions for setting up HyperTerm that is built into Win
> 95/98 for the communications.
>
> To find out what the status of the amplifier is, you need to use a
> modem communications program. Windows 95/98 comes with one called
> HyperTerminal. It is usually located in the ACCESSORIES program group.
> On Win98 it may not have been installed as the default and you can
> install it by inserting the Win98 CD and selecting it in the "Add
> Programs, Communications" menu.
>
> When you click on HyperTerminal from the START, PROGRAMS, ACCESSORIES
> menu it will open a program group on the screen.
>
> Click on HYPERTRM.EXE and it will open a window for a new connection.
> Give it a name, and in the next window select the "Connect Using:
> Direct to COMx" pulldown menu (in the bottom of the box on my version
> of Win95); select the Com port you will use. This is the same one that
> you were using with the AlphaRemote software. If the COM port you
> select is available it will open another box called "COMx Properties".
> Going down the list, select Bps-4800, Data bits-8, Parity-NONE, Stop
> bits-1, Flow control-NONE. Click OK to close the window. Now pull down
> the FILE menu and click PROPERTIES. Click the SETTING tab and then
> click ASCII SETUP at the bottom of the window.
> Click the box for "Echo typed characters locally" (it could have a
> check in the box). Click OK to close both windows.
>
> Plug in the amp (power off) and it should be communicating with the
> computer. Type VER and press the Enter key. The 87A should respondwith
> the firmware version number.
>
> ATTENTION ATTENTION !!!!!!!!!!!!!!
>
> If you see garble (or nothing) you will need to remove pin 22 of the
> 25-pin end of the cable (the 87A end). It is used to set the baudrate
> of the amplifier. Page 19 of the 87A manual has a complete explanation
> of the communications connections.
>
> When it is communicating OK, type SF and HF to display the Soft Fault
> and Hard Fault logs (press Enter key after each command). Save the
> result of those commands.
>
> A list of more commands is on pages 20 and 21 of the 87A manual (pages
> 40 and 41 in 87A Manual Rev 1.0)
> =============
> http://asktheham.com/node/46
> Alpha 87A Bandswitch Alignment
> published by administrator on Sat, 12/04/2010 - 21:01
> Forums:
>
> Alpha 87A Entries
>
> Setting bandswitch positions:
>
> With amplifier turned on, select 10 meter band by pushing switch for
> 28 MHz. Turn amplifier off and remove plug from Mains AC power.
>
> Remove amplifier cover and defeat both interlocks: the microswitch at
> center of amp and the metal spring that will short the HV to chassis
> (insulate the screw in the center of the hole in the spring).
>
> Note the position of the bandswitch fingers, they will be in the
> approximate position of Band 9 (10m) that is needed for the first step
> of realignment.
>
> Plug amplifier into Mains AC but do not turn on.
>
> Establish PC communications with amplifier (use Hyper Terminal or
> other modem program, do NOT use AlphaRemote software). Amplifier power
> is still OFF.
>
> Type "EXT ON" then 'ENTER'.
>
> Type "W B7BB FF" then 'ENTER'.
>
> On the PC, type "AC ON" then 'ENTER'.
>
> The amplifier should come up in the band switch alignment mode with
> only the band-select button 9 (28 MHz) LED flashing. The bandswitch
> will move to the end of its range (past the 10m position)
>
> Referencing the previously noted position for Band 9 (10m), move the
> bandswitch there by pressing the LOAD up/down buttons.
>
> Set each band switch position so that the switch wipers are centered
> by pressing the LOAD up/down buttons. Press 'ENTER' on the amplifier
> front panel to store the selected bandswitch position. The band switch
> will move to the next position and the next lower band-select button
> LED will
> light. After band switch position 1 is set the amplifier will go into
> WAIT mode.
>
> Type "EXT OFF" then 'ENTER'. EXT ON sets the factory mode which allows
> writing to all memory data locations and can be dangerous if left
> enabled.
>
> Turn off amplifier, restore interlocks to normal and put cover back on
> amplifier.
> ================
> http://asktheham.com/node/45
> Alpha 87A Autotune Function
> published by administrator on Sat, 12/04/2010 - 21:00
> Forums:
>
> Alpha 87A Entries
>
> The 87A Autotune (AlphaMax) function is not that of an antenna tuner.
> It constantly monitors the input power, output power, and grid current
> and tunes the motorized TUNE and LOAD capacitors for best efficiency.
> The optimum settings will change as you move across the
> band and if the drive power is changed.
>
> The amplifier measures the frequency of the drive signal and changes
> bands within one second when the radio is keyed on a new frequency. It
> goes to saved settings in memory, and retunes if it is needed. The
> Autotune function of the 87A works at about 30w of drive and higher
> (typically 800w output). It is at this level so that it does not try
> to retune when SSB signals drop between voice peaks.
>
> The 87A has high reflected power protection, tripping to standby if it
> exceeds 225w. This is almost 3:1 VSWR at 1500w output. This is to
> protect the PIN diodes in the T/R circuit from excessive voltages.
> Reducing the output power will allow transmitting into a higher VSWR.
>
> An antenna tuner capable of really handling 1500w under a wide variety
> of loads is almost the same size as the amplifier (like a Nye-Viking
> or Pal-Star tuner). If your antenna has a VSWR of over 3:1 on some
> bands, I would suggest making changes to the antenna(s) or using a
> heavy-duty antenna tuner.
>
> Log in or register to post comments
>
> N6AJR
>
> Sun, 01/30/2011 - 22:04
>
> Permalink
> The 87A and auto tuning
>
> I have noticed a lot of the time when I use my 80 or 160 antenns ( a
> sloper and a Verticle) that as I tune up the band, say from 1.800 to
> 1.835, the amp will show higher and higher reflected power, then will
> automatically adjust itself for a better match, this also happens if
> you raise the power level as you transmit.
>
> I ues my Alpha 87 A mostly in Alpha Max mode, where you press the load
> and enter buttons at the same time and the default ligh blinks ,
> indicating the Alpha Max mode. This makes the amp almost bullet proof.
>
> What a great amp. I have it set up to run on my Orion and most of the
> time I use my 3 element steppir for 10-20 m and my sloper and ver for
> 30 to 160 m. This makes them follow you around the band like a puppy.
> cool
> =============================
> http://asktheham.com/node/44
> Alpha 87A and FT-1000D Power Spike
> published by administrator on Sat, 12/04/2010 - 21:00
> Forums:
>
> Alpha 87A Entries
>
> Use of ALC is OK, but first the radio output must be set to the
> correct level for the output that you want from the amplifier. It is
> not a good idea to use ALC to force the radio output from 100w to the
> needed 50w, for example.
>
> The ALC control on the amplifier should be adjusted so that it limits
> the exciter from going ABOVE the desired level. It is to keep the amp
> from being overdriven and should not be needed if the radio is
> operated correctly.
>
> We do not recommend using the ALC feedback to the radio with modern
> solid-state transceivers. They have an internal ALC circuit that will
> limit the drive from the radio when adjusted correctly, and the
> external
> ALC is not necessary.
>
> Some FT-1000D radios output a spike of full power when first keyed if
> the power sontrols are not set correctly. Using the ALC feedback from
> the amplifier will not stop this because the amp must first be
> overdriven to generate ALC voltage, and the spike is faster than the
> feedback can happen.
>
> Please read these e-mails from the Amps Reflector archive for a
> discussion of the problem by Dick Ehrhorn:
>
> http://lists.contesting.com/pipermail/amps/1999-April/010468.html
>
> http://lists.contesting.com/pipermail/amps/1999-April/010483.html
>
> The trick is to lower both power controls (I think they are called RF
> PWR and DRIVE), instead of just one as the manual instructs. You may
> want to sign onto the Yaesu e-mail list on www.contesting.com and ask
> about it there. I don't have a picture of the FT-1000D front panel
> here, but I know there are two controls for power that must be
> adjusted
> lower to keep down the spike.
>
> Log in or register to post comments
>
> w0ric
>
> Fri, 01/28/2011 - 23:02
>
> Permalink
> ALC
>
> I've never ran the ALC connection. Only the relay cable from the
> 1000-D to the 87A. Seems to be working just fine.
>
> 73
> Rick
> W0RIC
>
> Log in or register to post comments
>
> K4VUD
>
> Sat, 01/29/2011 - 01:27
>
> Permalink
> ALC and 87a
>
> Follow the book.... just do not use ALC. ALC is for whoosies.
>
> Log in or register to post comments
>
> K4VUD
>
> Sat, 01/29/2011 - 01:35
>
> Permalink
> 87a and power spikes
>
> A "power spike" is a flaw in a transceiver whereby it puts out full
> power for a fraction of a second before it settles down to the RF
> power you set with your front panel controls. This is a common flaw in
> many radios, and I have first hand observation of it occurring in the
> K3, FT-897, IC-706, IC-718, and IC-7000. Many hams will tell you that
> these radios NEVER output a power spike, but they are simply thinking
> with love of the radio instead of facts.
>
> The spike will sometimes fool the OH SO TOUCHY Alpha 87a and cause it
> to fault and turn itself to Standby. I do not know what you can do
> about it except sell the radio or the amp and get a better one or
> other.
>
> Be especially careful if you have a 200 watt or 400 watt driver ...
> that is, the tranceiver has this level of RF output.
> ======================
> http://asktheham.com/node/43
> Alpha 87A AC Tap Settings
> published by administrator on Sat, 12/04/2010 - 20:59
> Forums:
>
> Alpha 87A Entries
>
> The AC voltage tap may still be set for 200v, which we have here.
> Measure your line voltage where the amp plugs in, then set the tap
> wire to the appropriate setting. The terminal strip is near the
> step-start fuse at the center of the amp.
>
> The first heavy white wire at the front end of the terminal does not
> move (if you have the optional fan there is also a black wire on the
> same screw). The second white wire moves to the other terminal to
> determine the tap. The second black wire should stay on the lug that
> is 2 positions from the first one (220vac). The 240 screw is 3
> positions
> from the first one (2 empty between the first wire and the 240).
> ======================
> http://asktheham.com/node/42
> Alpha 87A AC Module fuse
> published by administrator on Sat, 12/04/2010 - 20:59
> Forums:
>
> Alpha 87A Entries
>
> On the Simplified Schematic (87A Manual Fig 9) fuse F3 in the AC
> Module is shown as a 500ma fuse. It is really a 100ma fuse and the AC
> module must be removed to check it. If this is blown it will keep the
> 87A from running and it will NOT communicate with the PC via the
> serial port.
>
> To check the fuse, remove the nut at the front of the AC Module and
> the two screws on the rear of the chassis above and below the 20A fuse
> holders. When putting it back in, be sure to tighten the rear screws
> FIRST, then tighten the nut at the front. Doing this in reverse order
> can warp the chassis and may cause the bandswitch to bind up.
> ================
> http://asktheham.com/node/41
> Alpha 87A 40m Clapper Fix
> published by administrator on Sat, 12/04/2010 - 20:58
> Forums:
>
> Alpha 87A Entries
>
> 87A 40m (Segment 1) Clapper Fix
>
> 1) Establish computer communications with amplifier per 87A Operating
> Manual (pages 19-21).
>
> 2) Amplifier plugged in, power OFF.
>
> 3) Type: EXT ON (turns on FACTORY mode)
>
> 4) Type: DM B782[enter] (dump memory at location specified)
>
> a) If first pair of numbers is ØØ then proceed to step 7.
>
> b) If first pair of numbers is BØ type W B782 ØØ[enter]
>
> 5) Unplug 87A AC power, plug back in.
>
> 6) Repeat steps 3) and 4) to verify data written to memory.
>
> 7) Unplug 87A AC power, plug back in.
>
> 8) The amplifier is now ready for normal use.
> ============================
> http://asktheham.com/node/40
> Alpha 87A 17m Testing Bandswitch
> published by administrator on Sat, 12/04/2010 - 20:58
> Forums:
>
> Alpha 87A Entries
>
> A problem with the tuning on 17m can be caused by the bandswitch being
> a little bit out of alignment on that band. To test this, first
> manually select a lower band, then go to 17m. Try transmitting and
> tuning the amp. If you are able to tune it up, save the setting (press
> ENTER and then press the segment that you are on). Then manually
> select a higher band, then go to 17m, and try transmitting again. If
> the tuning changes, or if the 87A gets a Fault 17, it is the
> bandswitch alignment.
>
> We can send you instructions to do it, you will need to have a
> computer communicating with the amp before you can realign the
> bandswitch.
> =================
> http://lea.hamradio.si/~s55o/files/manuals/Alpha%2087a/87A%20Bandswitch%20Tuning.pdf
> FIX FOR ALPHA 87A BANDSWITCH FAULT
> de K6FG
> Many of our members have Alpha 87A amplifiers. Some of us have had a
> problem with recurring faults on one or more bands. Usually the fix
> involves moving to another band, keying down, and then trying again on
> the desired band. The >fault= generally appears with indicator LEDs 1
> & 5 lit. (In my case the problem occurred only on 17 meters.)
> The bad news is that Alpha confirmed that the cause is bandswitch
> misalignment on the particular band. The good news is that the problem
> is easily fixed via software instructions from a computer attached to
> the amplifier's serial port.
> The following are relevant excerpts from Alpha technical support
> emails:
> You will need to have a computer communicating with the amp before you
> can realign the band switch. Here are some notes on the 87A Fault
> protection and instructions for connecting the PC, followed by the 17m
> instructions.
> The 87A should 'talk' to the PC anytime it is plugged into mains
> power, even when it is turned off. This is the best troubleshooting
> tool that we have. Note that the 20A fuses must be good.
> Here are instructions for setting up HyperTerm that is built into Win
> 95/98 for the communications:
> To find out what the status of the amplifier is, you need to use a
> modem communications program. Windows 95/98 comes with one called
> HyperTerminal. It is usually located in the ACCESSORIES program group.
> On Win98 it may not have been installed as the default and you can
> install it by selecting the "Communications" selection on the AWindows
> Setup@ tab on the AAdd Programs@ screen within the Windows AControl
> Panel.@ (You may need to have your Windows installation CD inserted in
> your CD drive.)
> To use the HyperTerminal, click on HyperTerminal from the START,
> PROGRAMS, ACCESSORIES menu.
> Click on HYPERTRM.EXE and it will open a window for a new connection.
> Give it a name, and in the next window select the "Connect Using:
> Direct to COMx" pull down menu; select the Com port you will use. This
> is the same one that you use with the AlphaRemote software.
> If the COM port you select is available it will open another box
> called "COMx Properties". Going down the list, select Bps-4800, Data
> bits-8, Parity-NONE, Stop bits-1, Flow control-NONE. Click OK to close
> the window.
> Now pull down the FILE menu and click PROPERTIES. Click the SETTING
> tab and then click ASCII SETUP at the bottom of the window.
> Click the box for "Echo typed characters locally" (it could have a
> check in the box). Click OK to close both windows.
> Plug in the amp (power off) and it should be communicating with the
> computer.
> Type VER and press the Enter key. The 87A should respond with the
> firmware version number.
> If you see garbage (or nothing) you will need to remove pin 22 of the
> 25-pin end of the cable (the 87A end). It is used to set the baud rate
> of the amplifier. (Page 19 of the 87A manual has a complete
> explanation of the communications connections.)
> Once the amplifier is communicating properly with the computer, type
> SF and HF to display the Soft Fault and Hard Fault logs (press Enter
> key after each command). Save the result of those commands. A list of
> more commands is on pages 20 and 21 of the 87A manual (pages 40 and 41
> in 87A Manual Rev 1.0)
> NOW HERE IS THE PROGRAMMING INFORMATION (Please note that it is for 17
> meters, only):
> The memory address for the 17m band switch position is B7C0 .
> From the terminal program type:
> EXT ON (turns on 'factory mode')
> DM B7C0 (write down first two digits)
> W B7C0 xx (xx = original hex number up or down 2)
> If it [17 meters] works when you come from a lower band, increment the
> number. If it [17 meters] works coming from
> higher band, decrement the number.
> When done type:
> EXT OFF
> The following is a list of memory addresses for all of the band switch
> positions:
> 160m B7BB
> 80m B7BC
> 40m B7BD
> 30m B7BE
> 20m B7BF
> 17m B7C0 (This is a number Azero@, not a letter AO@)
> 15m B7C1
> 12m B7C2
> 10m B7C3
> Personal War Story:
> On my 87A, I raised the B7C0 number by two (from 77 to 79) and my 17
> meter band switch problem completely disappeared.
> The Windows (98SE) terminal program would not recognize COM6 which I
> use to connect to the 87A. Instead of simply (and easily) moving the
> DB9 connector to COM1, 2, 3 or 4, I chose to communicate with the
> amplifier the hard way: I installed a shareware program that
> recognized COM6. That program is Ckubed Terminal Emulation Program.
> It is available at the following website:
> http://ourworld.cs.com/hsc1953/download.htm
> Page 11 SOUTHERN CALIFORNIA DX CLUB August 2003
> ----------------------------------------------------------------------------
> http://asktheham.com/node/39
> Alpha 87A 17m Bandswitch Alignment
> published by administrator on Sat, 12/04/2010 - 20:57
> Forums:
>
> Alpha 87A Entries
>
> The memory address for the 17m bandswitch position is B7C0 .
>
>> From the terminal program type:
>
> EXT ON (turns on 'factory mode')
> DM B7C0 (write down first two digits)
> W B7C0 xx (xx = original hex number up or down 2)
>
> If it works when you come from a lower band, increment the number. If
> it works coming from higher band, decrement the number.
>
> When done type:
> EXT OFF
>
> memory locations for the bandswitch positions:
>
> 160m b7bb
> 80m b7bc
> 40m b7bd
> 30m b7be
> 20m b7bf
> 17m b7c0
> 15m b7c1
> 12m b7c2
> 10m b7c3
> ===========================
> http://asktheham.com/node/38
> Alpha 87A 10m Unlock
> published by administrator on Sat, 12/04/2010 - 20:57
> Forums:
>
> Alpha 87A Entries
>
> 1. Turn on the amplifier; wait until time delay completes.
>
> 2. Select - BAND 1.8 MHz, SEGMENT 1 (far left). Note the green LEDS in
> the
> push-button will illuminate.
>
> 3. When time delay completes switch amplifier to STBY.
>
> 4. Simultaneously depress both DEFAULT and ENTER. If done correctly,
> the green LEDs in the BAND and SEGMENT buttons will go out. If one LED
> is blinking, simultaneously depress both DEFAULT and ENTER again. If
> the LEDs do not go out, it will be necessary to turn off the amplifier
> then turn it back on, waiting for time delay to complete and repeating
> the above steps.
>
> The code sequence for your amplifier is ____-_____-_____-_____.
>
> The nine BAND buttons are designated 1.8, 3.5, 7, 10, 14, 18, 21, 24,
> and 28. The 1.8 button is "1", 3.5 is "2", 7 is "3", and so on.
> Depress the first code sequence button firmly; the LED below the
> button will start blinking when the code number has been read. If the
> LED does not blink, depress the button again. Depress the second
> button; note the blinking LED. Continue with the third and fourth in
> order. When all four digits are entered the amplifier automatically
> unlocks and switches to 28 MHz, you may operate on this band or select
> another. Once unlocked your amplifier will remain so. If you wish to
> re-lock out the ten and twelve meter coverage repeat the code entry
> sequence. You may unlock the coverage again at any time.
> ------------------------------------------
>
> To: Alpha87a@yahoogroups.com
> Subject: [Alpha87a] Alpha 87A 10m / 12m Unlock via Hyperterminal
> From: "Glenn AE0Q gm5bkc@gmail.com [Alpha87a]"
> <Alpha87a@yahoogroups.com>
> Date: Tue, 5 Jan 2016 10:23:40 -0700
>
> Alpha 87A 10m Unlock via Hyperterminal
>
> Instructions to unlock Alpha 87A on 10/12m via serial port:
>
> Connect to serial port using Hyperterminal, amp plugged in but turned
> off.
> Type commands below:
>
> EXT ON
> W B717 00
>
> Then unplug amp from AC power, wait a minute, plug back in.
>
> DO NOT make any mistakes typing, you are writing directly to the
> microprocessor code! Writing to the wrong address will be fatal.
>
> The 87A microprocessor reloads the operating program every time the
> amp is
> plugged in. This can cure some strange operating problems. The amp
> should
> be unplugged from AC power when not in use.
>
> Glenn AE0Q
> Alpha Amplifiers
> RKR DesignsLLC
> =============================
> http://asktheham.com/node/37
> Alpha 87A - Using AlphaMax
> published by administrator on Sat, 12/04/2010 - 20:56
> Forums:
>
> Alpha 87A Entries
>
> When the AlphaMax (Autotune) firmware is installed in the 87A, the
> TUNE and LOAD LEDs will blink to indicate what the AlphaMax program
> would do if it was enabled.
>
> An addendum to the 87A manual was included with AlphaMax kits that
> were installed in the field, or you can download a copy of the new
> version of the 87A manual (with instructions for using AlphaMax) from
> our web site:
>
> http://www.rfconcepts.com
>
> You should tune up the amp with your antennas on each band/segment and
> save the settings in USER memories. You do this by pressing ENTER and
> then while the ENTER LED is flashing, press the segment that you are
> on. When changing bands the 87A first goes to the USER memory setting.
> If further tuning is needed it will make the adjustments if the
> Autotune mode (AlphaMax) is enabled. If it is not enabled, the TUNE
> and/or LOAD LEDs will blink to indicate what direction those would be
> moved.
>
> If it is not in Autotune and the user settings are not at all close to
> desirable, it will fall back to factory-saved default settings (for a
> 50 ohm load) and the DEFAULT LED will light solid.
>
> The Autotune function is enabled by pressing the LOAD^ and ENTER
> buttons at the same time when the amp is in operate and warmed up. The
> DEFAULT LED will flash when Autotune is enabled and the amp is in
> operate and warmed up.
>
> The DEFAULT LED indicates 3 conditions of the amp:
>
> 1) not lit means it is in original 87A function of automatically
> measuring transmitted frequency and recalling memory settings for band
> segment closest to that frequency detected.
>
> 2) blinking means that autotune (AlphaMax) is enabled, amp will
> dynamically retune if drive changes (as when yelling louder than
> normal in a pileup, etc).
>
> 3) lit solid means the factory memory setting has been recalled
>
> Please note that the TUNE meter is a rough indicator to allow the amp
> to be tuned with low drive levels so that it is close to being set for
> 1500w output. Once you increase the drive and are close to 1500w out,
> fine tune by adjusting the TUNE and LOAD controls for maximum output
> at the drive level you are at. This should correspond to a dip in the
> plate current. The TUNE LED may be a number of LEDs off center to
> either side. The most useful multimeter parameter to monitor when
> transmitting is the Ip (plate current), also watching the Ig (grid
> current).
>
> The TUNE meter is calibrated on 20m when the amp is tuned up for 1500w
> out, with new tubes. As the tubes age, it will indicate off center a
> bit. Line voltage that is not at the nominal value for each range
> (200, 220 or 240v) may also affect the TUNE calibration.
>
> Since the 87A has memories that should be saved for the tuneup
> settings for each band segment, the TUNE meter isn't really as useful
> as it is with a manually tuned amp (Alpha 89/91B/99).
> =================
> http://asktheham.com/node/8
>
> ============================================================================
> http://df3cb.com/alpha87a/documentation/commands.php
>
> Reference: Alpha 87A Command
>
> HELP:
> AC STAT HF
> SF PANEL SER
> DATE VER HNDSHK
> DM ANTENNA BYE
> OPER MODE BAND
> SEG TUNE LOAD
> FREQ DEF ENT
> METER PWR REFL
> GRID LOCK AD
> ADS GPIO AUTOTUNE
>
>
> Power On/Off Command
>
> Command Description
> AC Is AC power on or off?
> AC ON Turns AC power on
> AC OFF Turns AC power of
>
>
> Set Commands
>
> Command Description
> BAND # (1-9) Sets band switch to any band one through nine
> DEF Sets tune, load and frequency to default or factory
> settings
> ENT Use with SEG command for saving data
> FREQ # (in kHz) Sets up unit for this entered frequency
> LOAD DOWN Adjusts load capacitor down one step
> LOAD UP Adjusts load capacitor up one step
> METER HV Sets multimeter to HV mode & reports value
> METER IP Sets multimeter to IP mode & reports value
> METER TUNE Sets multimeter to TUNE mode & reports value
> MODE HIGH Sets high voltage power supply to high mode
> MODE LOW Sets high voltage power supply to low mode
> OPER OFF Sets to standby mode
> OPER ON Sets to operate mode if ready
> SEG # (1-5) Sets segment to entered value
> TUNE DOWN Sets tune capacitor down one step
> TUNE UP Sets tune capacitor up one step
>
>
>
> Poll Commands
>
> Command Description
> STAT Reports unit status
> PWR Reports current forward power out in watts
> REFL Reports current load reflected power in watts
> METER Reports current reading of the front panel multimeter
> GRID Reports current grid current in mA
>
> FREQ What frequency is the unit on or last frequency used?
> LOAD Reports current load capacitor setting (0-100)
> MODE Reports current HV power supply setting, HI or LO
> OPER Reports whether in operate or standby
> SEG Reports current segment setting
> TUNE Reports current tune capacitor setting (0-100)
>
>
>
> STAT Unit Status Report
>
> ????????????????????
> STATE = OFF MODE = LOW
> 10-METER ENABLED PANEL ENABLED
> FREQUENCY = 18150 kHz
> BAND = 6 SEGMENT = 3
> TUNE = 40 LOAD = 70
> ANTENNA = 5
> ????????????????????????????
>
>
> Report Example Power off Example Power
> on Upon 240VAC
> ------ ----------------- ---------------- -----------
> state warm-up (AC) AMPLIFIER IS OFF (AC ON)
> AMPLIFIER IS ON
> standby, or operate: HV mode, low or high (STAT) STATE =
> OFF MODE = LOW ALPHA 87A ALPHA 87A
> 24-30 MHz enabled or disabled 10-METER
> ENABLED PANEL ENABLED VERSION UPX-X108-G VERSION
> 1.00-AT
> panel enabled or disabled FREQUENCY =
> 14000 kHz COPYRIGHT 1992 COPYRIGHT
> 1992, 1999
> frequency last entered BAND = 5
> SEGMENT = 1 ETO, INC. ALPHA/POWER,
> INC.
> band last selected TUNE = 48 LOAD
> = 57 POWER ON SEQUENCE POWER ON SEQUENCE
> segment last used USER
> tune and load capacitor positions 3
> MINUTE WARM-UP
> NOT VALID DURING WARM-UP
> ...
> MODE = HIGH
> STATE = STANDBY
> STATE = OPERATE
> ???????????????????????????????????????????????????????
>
> Nov 8, 2014:
> HF:
> HFAULT LOG = 24 24 24 22 37 37 24 24 HF bridge arc to PCB
> fixed with fishpaper shield
>
> SF:
> SFAULT LOG = 17 17 17 17 17 17 17 17
>
>
> Reference: Alpha 87A Fault Codes
>
>
>
> Code Type Description
> 1 Soft Receive PIN back bias voltage not at minimum
> required level with key down and no RF drive.
> 2 Hard Five volt supply voltage too low.
> 3 Hard Five volt supply voltage too high.
> 5 Hard Plate voltage abnormally low.
> 6 Hard Plate voltage abnormally high.
> 7 Soft Cathode and/or power PIN diode back bias
> (-109V) not switching to the required low level with key down.
> 8 Soft Transmit PIN diode back bias below minimum
> required value key up.
> 9 Soft Transmit PIN diode forward current below
> minimum required value key down.
> 11 Soft Transmit PIN diode forward current exceeds
> maximum limit key down.
> 12 Soft Excessive input reflected power.
> 13 Soft Excessive and unsafe drive power.
> 14 Soft Excessive load reflected power or RF voltage.
> May be caused by excessive load VSWR at an otherwise acceptable power
> (e.g. 4:1 at 1.5 kW)
> or excessive power at otherwise acceptable
> load VSWR (e.g. 2.5 kW at 1.9:1).
> 16 Soft Plate current greater than 1.35 amp for more
> than 4 seconds continuous. Note: The IP button LED flashes for several
> seconds before a fault 16 IP trip occurs.
> 17 Soft Abnormally low or high amplifier power gain.
> Usually due to extreme mis-tuning or possibly an RF arc. (XCVR drive
> too high)
> 18 Soft Filament current less than 2.0 amp. Possible
> open tube filament.
> 20 Soft Filament current greater than 3.5 amp.
> Possible shorted filament.
> 21 Soft Excessive tube temp. in transmit (key down);
> abnormal dissipation and/or insufficient airflow.
> 22 Hard Control system fault; D/A feedback) not
> working.
> 23 Hard Control system fault; D/A feedback 1 not
> working.
> 24 Hard System voltage fault. High voltage, +/-15
> volts, or 109 volts below safe operating level. (HF bridge arc to PCB)
> 26 Soft RF drive before or without amplifier keyed
> (possibly mis-sequenced T/R), or attempted automatic band change with
> excessive RF drive.
> 29 Soft Attempt to transmit on invalid frequency, such
> as above 24 MHz without unlocking 24-30 MHz coverage.
> 31 Soft Excessive grid current; above 100mA
> continuously for 2 seconds. NOTE: Red LED in IG bargraph flashes
> before IG trip occurs.
> 33 Soft Control system fault; TUNE capacitor not
> initializing.
> 34 Soft Control system fault; TUNE capacitor not
> moving or zero sensor position not working.
> 35 Soft Control system fault; LOAD capacitor not
> initializing.
> 36 Soft Control system fault; LOAD capacitor not
> moving or zero sensor not working.
> 37 Hard Control system fault; Bandswitch not moving.
> 99 Fault 99 Unit refuses to turn on. Same hard fault
> occured 6 consecutive times without one successful power-up.
>
>
> February 2, 2014:
> To clear a Fault 99 on an Alpha 87A amplifier with a PC connected:
> Type in the following commands and enter them for each new line.
>
> EXT ON
> W B71A FF
> W B71B FF
> W B71C FF
> W B71D FF
> W B71E FF
> W B71F FF
> W B720 FF
> W B721 FF
> W B724 FF
> W B725 FF
> W B726 FF
> W B727 FF
> W B728 FF
> W B729 FF
> W B72A FF
> W B72B FF
> W B72C 0C
> W B72D B5
> W B7E0 FF
> W B7E1 FF
> W B7E2 FF
> W B7E3 FF
> W B7E4 FF
> W B7E5 FF
> W B7E6 FF
> W B7E7 FF
> HF
> SF
>
> When you type HF and SF they should show all 00. Unplug the 87A from
> the mains power for 30 seconds.
> This resets the microprocessor. The amplifier is now ready for normal
> use
> ==========================================
>
> Archived Ask The Ham web site:
> https://web.archive.org/web/20130805035808/http://asktheham.com/forum/8
> https://web.archive.org/web/*/http://asktheham.com/forum/*
> -----------------------------------------------------------------------------------------
>
>
>
>> On Tue, 30 Jul 2019 11:37:14 -0400, Dave <rocketnj@gmail.com> wrote:
>>
>> Hi all
>>
>> Looking at an old 87A for a friend.
>> This is a 91xxx s/n without AlphaMax and NO updates done to amp.
>>
>> Originally faulting with fault 8. Replaced bad RX PIN diodes with 1N4007
>> diodes and TX PIN with pair of UM4006D. No more fault 8.
>>
>> Now whenever you press TUNE DOWN it immediately faults with fault 33. (Tune
>> motor failed to initialize).
>>
>> Another clue is on power up both Load
>> LEDs flash but only the TINE UP LED flashes twice. (Tune down does not
>> flash). But Tune Down LED does light when pressing Tune Down.
>>
>> Any ideas appreciated
>>
>> Dave wo2x
>>
>> Sent from my waxed string and tin cans.
> <87a_commands.txt>
> <87a_fuses.txt>
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