RE; SB-200 circuit breaker.
I have had s few of these amps in the past. All seemed to
suffer from heat problems, no doubt to the poor (in my
opinion) ventelation. The muffin fan is a good start.
However, I had the Harbach mod in one of the units. It
failed (actually the unit was like this when I bought it).
I didn't see the problem until I noticed the plate current
did not cut off during standby. Harbach uses a circuit that's
diffrent in this amp as opposed to the SB-200 (or TL-922).
It has to bias the tube and control the relay, etc.
In any event, replaced the componenets on both tube sockets
and switched to a small, high speed relay for exciter interface.
I removed the Harbach mod which cured the problem.
ed K0kl
----- Original Message -----
From: <amps-request@contesting.com>
To: <amps@contesting.com>
Sent: Monday, August 27, 2007 3:04 AM
Subject: Amps Digest, Vol 56, Issue 38
> Send Amps mailing list submissions to
> amps@contesting.com
>
> To subscribe or unsubscribe via the World Wide Web, visit
> http://lists.contesting.com/mailman/listinfo/amps
> or, via email, send a message with subject or body 'help' to
> amps-request@contesting.com
>
> You can reach the person managing the list at
> amps-owner@contesting.com
>
> When replying, please edit your Subject line so it is more specific
> than "Re: Contents of Amps digest..."
>
>
> Today's Topics:
>
> 1. Re: SB-200 circuit breakers (Tom Osborne)
> 2. Re: SB-200 circuit breakers (jeremy-ca)
> 3. Re: SB-200 circuit breakers (Tom Osborne)
> 4. SB-200 circuit breaker (Tom Osborne)
> 5. Re: SB-200 circuit breaker (jeremy-ca)
> 6. Re: SB-200 circuit breakers (jeremy-ca)
> 7. Re: SB-200 circuit breaker (Dan Hearn)
> 8. Patent - was: Heat Dissipating 8877 HV Plate Caps (Peter Chadwick)
> 9. Re: SB-200 circuit breakers (Gudguyham@aol.com)
>
>
> ----------------------------------------------------------------------
>
> Message: 1
> Date: Sun, 26 Aug 2007 17:22:19 -0700
> From: "Tom Osborne" <w7why@verizon.net>
> Subject: Re: [Amps] SB-200 circuit breakers
> To: <Amps@contesting.com>
> Message-ID: <008601c7e840$5502db30$eec8fea9@Tom>
> Content-Type: text/plain; format=flowed; charset=iso-8859-1;
> reply-type=original
>
> Hi Lou
>
> I guess I didn't explain it right. What I meant is that after it cools
> down, I can manually reset the breaker. If I push on it right after it
> trips, it won't reset. Actually, after a while I can hear an audible
> 'click' and then I can manually reset it.
> Tom W7WHY
>
> >
> > After it
> > cools down a bit, it will come back on.
> >
> > As far as I know the breakers are not self re-setting, are you sure you
> > are
> > not manually re-setting it? If you are not, I don't think the breaker
is
> > shutting off. I am pretty sure you have to press it to make it go back
on
> > if IN
> > FACT it has tripped. Maybe you explained it wrong? Lou
> >
> >
> >
> > ************************************** Get a sneak peek of the all-new
AOL
> > at
> > http://discover.aol.com/memed/aolcom30tour
> >
>
>
>
> ------------------------------
>
> Message: 2
> Date: Sun, 26 Aug 2007 20:28:18 -0400
> From: "jeremy-ca" <km1h@jeremy.mv.com>
> Subject: Re: [Amps] SB-200 circuit breakers
> To: "Tom Osborne" <w7why@verizon.net>, <Amps@contesting.com>
> Message-ID: <014701c7e841$2c84fde0$6500a8c0@KITTYMA123>
> Content-Type: text/plain; format=flowed; charset="iso-8859-1";
> reply-type=original
>
> Three possibilities come to mind.
>
> - Defective breaker. Possible but quite rare.
>
> - Leaky filter caps. A very good possibility if they are original. Leave
the
> amp on for a half hour or so and then shut off. Make sure the HV is down
to
> zero and pull the plug. Feel the caps. If they are more than just barely
> warm they should be replaced. The plate meter will not show the capacitor
or
> bleeder current. Get 220 MF 450V Cornell Dublier 381LX series caps from
> Mouser. They are snap locks but all can be oriented to fit existing holes.
> Replace the 8 bleeder resistors with 75K 3W MOX, also from Mouser.
>
> - Bad tube or tubes. Actually not bad but not compatible with the SB-200
> design. Some Chinese and especially Russian tubes have different
> interelectrode capacitances and lower mu than the original Cetrons and
> become unstable. Unless you want to install a neutralization circuit and
> possibly increase the operating bias the best step is to replace the
tubes.
> There are still many good and even NOS Cetrons around. BTW, what brand are
> they?
>
> Carl
> KM1H
>
>
> ----- Original Message -----
> From: "Tom Osborne" <w7why@verizon.net>
> To: <Amps@contesting.com>
> Sent: Sunday, August 26, 2007 6:16 PM
> Subject: [Amps] SB-200 circuit breakers
>
>
> > Hi All
> >
> > On my SB-200, the front circuit breaker trips after half hour or so of
> > operation on RTTY. If running RTTY, I usually keep it down to 200-250
> > watts. It is the same breaker, the front one, that always trips. After
> > it
> > cools down a bit, it will come back on. The plate current is only
running
> > about 300 ma or so.
> >
> > The tubes are fairly new (4 months) and don't run red when operating
RTTY
> > at
> > 200-250 watts. I also have some muffin fans on top with the lid open to
> > take out some of the heat.
> >
> > In looking at the schematic, the breakers are in the primary of the
power
> > transformer. What causes them to trip, heat? There doesn't seem to be
> > that
> > much with the extra fans on top. 73 and thanks
> > Tom W7WHY
> >
> >
> > _______________________________________________
> > Amps mailing list
> > Amps@contesting.com
> > http://lists.contesting.com/mailman/listinfo/amps
> >
>
>
>
> ------------------------------
>
> Message: 3
> Date: Sun, 26 Aug 2007 18:35:25 -0700
> From: "Tom Osborne" <w7why@verizon.net>
> Subject: Re: [Amps] SB-200 circuit breakers
> To: <Amps@contesting.com>
> Message-ID: <003401c7e84a$8b882d90$eec8fea9@Tom>
> Content-Type: text/plain; format=flowed; charset=iso-8859-1;
> reply-type=response
>
> Hi Carl
>
> Filter caps have been recently replaced. They are 100uf at 450 volts. I
see
> in the schematic that the originals were 125uf. I will do the 'heat' test
> and see if they do in fact get warm.
>
> Tubes were replaced just 3 or 4 months ago. They are Taylor tubes.
>
> It is a problem that has just reared its ugly head in the past few weeks.
I
> used to run the amp around 300 watts on RTTY with no problems, but just
> lately it has started tripping the one breaker, and only at 200 watts.
>
> I guess I could just solder a wire across the breaker :-) 73
>
> Tom W7WHY
>
>
>
>
> > Three possibilities come to mind.
> >
> > - Defective breaker. Possible but quite rare.
>
> >
> > - Leaky filter caps. A very good possibility if they are original. Leave
> > the amp on for a half hour or so and then shut off. Make sure t>he HV
is
> > down to zero and pull the plug. Feel the caps. If they are >more than
> > just barely warm they should be replaced. The plate meter >will not
show
> > the capacitor or bleeder current. Get 220 MF 450V >Cornell Dublier
381LX
> > series caps from Mouser. They are snap locks >but all can be oriented
to
> > fit existing holes. Replace the 8 bleeder resistors with 75K 3W MOX,
also
> > from Mouser.
>
> > - Bad tube or tubes. Actually not bad but not compatible with the
SB->200
> > design. Some >Chinese and especially Russian tubes have different
> > interelectrode capacitances and lower mu than the original Cetrons >and
> > become unstable. Unless you want to install a neutralization circuit
>and
> > possibly increase the operating bias the best step is to replace the
> > >tubes. There are still many good and even NOS Cetrons around. >BTW,
what
> > brand are they?
> >
> > Carl
> > KM1H
> >
> >
> >
> >
> >> Hi All
> >>
> >> On my SB-200, the front circuit breaker trips after half hour or so of
> >> operation on RTTY. If running RTTY, I usually keep it down to 200-250
> >> watts. It is the same breaker, the front one, that always trips.
After
> >> it
> >> cools down a bit, it will come back on. The plate current is only
running
> >> about 300 ma or so.
> >>
> >> The tubes are fairly new (4 months) and don't run red when operating
RTTY
> >> at
> >> 200-250 watts. I also have some muffin fans on top with the lid open
to
> >> take out some of the heat.
> >>
> >> In looking at the schematic, the breakers are in the primary of the
power
> >> transformer. What causes them to trip, heat? There doesn't seem to be
> >> that
> >> much with the extra fans on top. 73 and thanks
> >> Tom W7WHY
>
>
>
> ------------------------------
>
> Message: 4
> Date: Sun, 26 Aug 2007 18:51:42 -0700
> From: "Tom Osborne" <w7why@verizon.net>
> Subject: [Amps] SB-200 circuit breaker
> To: <Amps@contesting.com>
> Message-ID: <001c01c7e84c$d1a553a0$eec8fea9@Tom>
> Content-Type: text/plain; format=flowed; charset=iso-8859-1;
> reply-type=original
>
> Hi Carl
>
> I did that and the caps are barely warm, but the bleeders are really hot.
> Too hot to touch.
>
> Tom W7WHY
>
>
> > - Leaky filter caps. A very good possibility if they are original. Leave
> > the amp on for a half hour or so and then shut off. Make sure the >HV
is
> > down to zero and pull the plug. Feel the caps. If they are more >than
> > just barely warm they should be replaced.
>
>
>
> ------------------------------
>
> Message: 5
> Date: Sun, 26 Aug 2007 23:08:55 -0400
> From: "jeremy-ca" <km1h@jeremy.mv.com>
> Subject: Re: [Amps] SB-200 circuit breaker
> To: "Tom Osborne" <w7why@verizon.net>, <Amps@contesting.com>
> Message-ID: <01d401c7e857$9c7f84b0$6500a8c0@KITTYMA123>
> Content-Type: text/plain; format=flowed; charset="iso-8859-1";
> reply-type=original
>
> Thats because they are running close to max ratings. Replacing them with
75K
> will cut down on the heat and give adequate equalizing. The bleed down
will
> take a bit longer. Heat kills electrolytics.
>
> Carl
> KM1H
>
>
> ----- Original Message -----
> From: "Tom Osborne" <w7why@verizon.net>
> To: <Amps@contesting.com>
> Sent: Sunday, August 26, 2007 9:51 PM
> Subject: [Amps] SB-200 circuit breaker
>
>
> > Hi Carl
> >
> > I did that and the caps are barely warm, but the bleeders are really
hot.
> > Too hot to touch.
> >
> > Tom W7WHY
> >
> >
> >> - Leaky filter caps. A very good possibility if they are original.
Leave
> >> the amp on for a half hour or so and then shut off. Make sure the >HV
is
> >> down to zero and pull the plug. Feel the caps. If they are more >than
> >> just barely warm they should be replaced.
> >
> > _______________________________________________
> > Amps mailing list
> > Amps@contesting.com
> > http://lists.contesting.com/mailman/listinfo/amps
> >
>
>
>
> ------------------------------
>
> Message: 6
> Date: Sun, 26 Aug 2007 23:20:17 -0400
> From: "jeremy-ca" <km1h@jeremy.mv.com>
> Subject: Re: [Amps] SB-200 circuit breakers
> To: "Tom Osborne" <w7why@verizon.net>, <Amps@contesting.com>
> Message-ID: <01f501c7e859$33ea1260$6500a8c0@KITTYMA123>
> Content-Type: text/plain; format=flowed; charset="iso-8859-1";
> reply-type=original
>
> Hmmm, Im not a fan of the Taylor label, Ive had several problems with them
> right out of the box. Im not sure how many Chinese factories are producing
> 572B's and prints which label.
>
> Leave the perforated cover off and the lid up and see if you can catch a
> tube starting to glow red when operating. If they stay dark and plate
> current doesnt sore they are likely OK,
>
> I have put clip leads across those breakers while trying to find a problem
> but do so at your own risk More than once Ive made a 2 handed grab for
the
> on/off switch while a tube is approaching bright orange. Luckily the tubes
> survived the extreme abuse.
>
> Carl
> KM1H
>
> ----- Original Message -----
> From: "Tom Osborne" <w7why@verizon.net>
> To: <Amps@contesting.com>
> Sent: Sunday, August 26, 2007 9:35 PM
> Subject: Re: [Amps] SB-200 circuit breakers
>
>
> > Hi Carl
> >
> > Filter caps have been recently replaced. They are 100uf at 450 volts. I
> > see
> > in the schematic that the originals were 125uf. I will do the 'heat'
test
> > and see if they do in fact get warm.
> >
> > Tubes were replaced just 3 or 4 months ago. They are Taylor tubes.
> >
> > It is a problem that has just reared its ugly head in the past few
weeks.
> > I
> > used to run the amp around 300 watts on RTTY with no problems, but just
> > lately it has started tripping the one breaker, and only at 200 watts.
> >
> > I guess I could just solder a wire across the breaker :-) 73
> >
> > Tom W7WHY
> >
> >
> >
> >
> >> Three possibilities come to mind.
> >>
> >> - Defective breaker. Possible but quite rare.
> >
> >>
> >> - Leaky filter caps. A very good possibility if they are original.
Leave
> >> the amp on for a half hour or so and then shut off. Make sure t>he HV
is
> >> down to zero and pull the plug. Feel the caps. If they are >more than
> >> just barely warm they should be replaced. The plate meter >will not
show
> >> the capacitor or bleeder current. Get 220 MF 450V >Cornell Dublier
381LX
> >> series caps from Mouser. They are snap locks >but all can be oriented
to
> >> fit existing holes. Replace the 8 bleeder resistors with 75K 3W MOX,
also
> >> from Mouser.
> >
> >> - Bad tube or tubes. Actually not bad but not compatible with the
SB->200
> >> design. Some >Chinese and especially Russian tubes have different
> >> interelectrode capacitances and lower mu than the original Cetrons >and
> >> become unstable. Unless you want to install a neutralization circuit
>and
> >> possibly increase the operating bias the best step is to replace the
> >> >tubes. There are still many good and even NOS Cetrons around. >BTW,
> >> what
> >> brand are they?
> >>
> >> Carl
> >> KM1H
> >>
> >>
> >>
> >>
> >>> Hi All
> >>>
> >>> On my SB-200, the front circuit breaker trips after half hour or so of
> >>> operation on RTTY. If running RTTY, I usually keep it down to 200-250
> >>> watts. It is the same breaker, the front one, that always trips.
After
> >>> it
> >>> cools down a bit, it will come back on. The plate current is only
> >>> running
> >>> about 300 ma or so.
> >>>
> >>> The tubes are fairly new (4 months) and don't run red when operating
> >>> RTTY
> >>> at
> >>> 200-250 watts. I also have some muffin fans on top with the lid open
to
> >>> take out some of the heat.
> >>>
> >>> In looking at the schematic, the breakers are in the primary of the
> >>> power
> >>> transformer. What causes them to trip, heat? There doesn't seem to
be
> >>> that
> >>> much with the extra fans on top. 73 and thanks
> >>> Tom W7WHY
> >
> > _______________________________________________
> > Amps mailing list
> > Amps@contesting.com
> > http://lists.contesting.com/mailman/listinfo/amps
> >
>
>
>
> ------------------------------
>
> Message: 7
> Date: Sun, 26 Aug 2007 20:39:37 -0700
> From: "Dan Hearn" <dhearn@air-pipe.com>
> Subject: Re: [Amps] SB-200 circuit breaker
> To: "Tom Osborne" <w7why@verizon.net>, <Amps@contesting.com>
> Message-ID: <ACEGINBFNLHLHJAHIHCPOEMPDLAA.dhearn@air-pipe.com>
> Content-Type: text/plain; charset="us-ascii"
>
> Tom, I once had a similar problem with my air conditioner, it would run
for
> several minutes and then the breaker would kick out. I was ready to think
> about replacing the compressor when a maintenance man at work suggested
that
> I measure the actual current to be sure the breaker was not bad. They have
> riveted joints in them and can develope increased IR drop with age. He
> loaned me his clip on ammeter and, sure enough the current thru the
breaker
> was less than its rating when it kicked out. Replaced the breaker and
> everything OK then.
> 73, Dan, N5AR
>
> -----Original Message-----
> From: amps-bounces@contesting.com [mailto:amps-bounces@contesting.com]On
> Behalf Of Tom Osborne
> Sent: Sunday, August 26, 2007 6:52 PM
> To: Amps@contesting.com
> Subject: [Amps] SB-200 circuit breaker
>
>
> Hi Carl
>
> I did that and the caps are barely warm, but the bleeders are really hot.
> Too hot to touch.
>
> Tom W7WHY
>
>
> > - Leaky filter caps. A very good possibility if they are original. Leave
> > the amp on for a half hour or so and then shut off. Make sure the >HV
is
> > down to zero and pull the plug. Feel the caps. If they are more >than
> > just barely warm they should be replaced.
>
> _______________________________________________
> Amps mailing list
> Amps@contesting.com
> http://lists.contesting.com/mailman/listinfo/amps
>
>
>
>
> ------------------------------
>
> Message: 8
> Date: Mon, 27 Aug 2007 09:34:01 +0200 (CEST)
> From: Peter Chadwick <g3rzp@g3rzp.wanadoo.co.uk>
> Subject: [Amps] Patent - was: Heat Dissipating 8877 HV Plate Caps
> To: amps@contesting.com
> Message-ID: <13993505.51961188200041101.JavaMail.www@wwinf3005>
> Content-Type: text/plain; charset=UTF-8
>
> The main use of a patent is that it looks good on your resume.
> Sometimes an employer pays a good bonus - mine pays $5000 - for a patent.
> Mostly, the writing up of the thing and dealing with the questions is more
trouble than it's worth - even for $5k! (I have to pay 40% tax on the
$5k....)
>
> You know you're getting old when you've got expired patents.
>
> 73
> Peter G3RZP
>
> ------------------------------
>
> Message: 9
> Date: Mon, 27 Aug 2007 04:04:21 EDT
> From: Gudguyham@aol.com
> Subject: Re: [Amps] SB-200 circuit breakers
> To: w7why@verizon.net, Amps@contesting.com
> Message-ID: <cea.18399bbc.3403df85@aol.com>
> Content-Type: text/plain; charset="US-ASCII"
>
>
> In a message dated 8/26/2007 9:36:31 P.M. Eastern Daylight Time,
> w7why@verizon.net writes:
>
> Filter caps have been recently replaced. They are 100uf at 450 volts. I
see
>
> in the schematic that the originals were 125uf. I will do the 'heat'
test
> and see if they do in fact get warm.
>
>
>
> I think 100uf caps are too small a value, I would have opted for 150's or
> better. I doubt if that is the problem though. Lou
>
>
>
> ************************************** Get a sneak peek of the all-new AOL
at
> http://discover.aol.com/memed/aolcom30tour
>
>
> ------------------------------
>
> _______________________________________________
> Amps mailing list
> Amps@contesting.com
> http://lists.contesting.com/mailman/listinfo/amps
>
>
> End of Amps Digest, Vol 56, Issue 38
> ************************************
>
_______________________________________________
Amps mailing list
Amps@contesting.com
http://lists.contesting.com/mailman/listinfo/amps
|