Hi John,
In a message dated 96-04-06 12:32:24 EST, you write:
<snip>
>Info on Semi- and Super-Catode-Driven Amplifiers is available from
>QST p 34 July 1967
>Ham Radio p 73 Nov 86
>Ham Radio p 43 Feb 87 with a minor correction in HR p 50 Apr 87
>
>73 John W0UN
>
I've never been able to duplicate the result the results claimed in those
articles. To the contrary, I've found (and other engineers have confirmed)
IMD increased and stability decreased by following the suggestions in that
series.
While the original Collins circuit worked very well (I think it was one of
the best and most innovative designs ever), applying Collin's techniques to
triodes or class AB2 amplifiers without IMD and stability testing isn't a
good idea.
If you look at any of the circuits suggested by actual design engineers at
Eimac, and published in official Eimac data like "Care and Feeding of Power
Grid Tubes" or in tube data sheets, the "Super Cathode Driven" circuits are
nowhere to be found. I think that tells us something.
73 Tom
>From jfunk@adams.net (jim funk) Sun Apr 7 05:29:50 1996
From: jfunk@adams.net (jim funk) (jim funk)
Subject: 599s
Message-ID: <9604070429.AA30399@golden.adams.net>
Seems to me that signal reports in contests, while "meaningless", serve as
spacers and help maintain rhythm to contacts. And you're right, Trey.
Contests don't all have to be the same.
73, Jim N9JF [599 IL ;>)]
>From Marijan Miletic <s56a@s55tcp.ampr.org> Sun Apr 7 10:25:42 1996
From: Marijan Miletic <s56a@s55tcp.ampr.org> (Marijan Miletic)
Subject: Tetrode QRO
Message-ID: <12652@s55tcp.ampr.org>
Hi Garry, we seem to be tuned at the same wavelength (no input coils either)!
I modified my SB-220 by grounding grids directly as one of the initial
designers admited it was mistake to introduce RF feedback without the control
of the phase relationship over the 80-10m. It saves me some power on IC-735.
There is elegant DL EME PSU using 5 x 500V with 1N4007's and TV capacitors and
plain vanila Zeners for a screen two-way protection. Another VHF trick is to
ground screen and use two negative supplies with floating heather voltage.
I prefer KISS approaches...
73 de Mario, S56A, N1YU.
>From trogo@primenet.com (Tony Rogozinski) Sun Apr 7 07:35:17 1996
From: trogo@primenet.com (Tony Rogozinski) (Tony Rogozinski)
Subject: DG tells us how to talk
Message-ID: <199604070635.XAA18759@usr3.primenet.com>
At 11:07 PM 4/6/96 EST, Douglas S. Zwiebel wrote:
>Weh, ih we aw taw tha way, we onnee nee a tweh our tes so we aw can geh mo
slee.
>I LIKE IT! Kinda like 5nnt5 on cw, right? LET'S DO IT. de Doug KR2Q :-)
>
I like : . -. -. -. -. (ARRL CW) better.
73
N7BG/TU5A
>
Tony Rogozinski N7BG
VooDoo Contest Group
trogo@primenet.com
("VooDoo" - white magic from Africa)
I Collect TELEGRAPH KEYS - Especially "Bugs"
Call Me At 1-800-966-6264 If You Have Any To Sell Or Trade
>From oo7@astro.as.utexas.edu (Derek Wills) Sun Apr 7 08:38:46 1996
From: oo7@astro.as.utexas.edu (Derek Wills) (Derek Wills)
Subject: 599s
Seems to me that signal reports in contests, while "meaningless",
serve as spacers and help maintain rhythm to contacts.
73, Jim N9JF [599 IL ;>)]
That's what it has always seemed to me. When a DX station sends 599,
it means "got you", and in a contest it's the equivalent of saying
"please copy...", not that I ever say that (gack).
There's nothing wrong with having tests of copying skills, but they
should be separate events from the traditional contests - perhaps one
station sends a verse or two from one of the Homeric odysses, in the
original Greek, and the other translates it and sends it back in English.
By comparing the original and translation, both stations know that the
information was passed successfully.
I use contests mainly as a DXing tool, and don't wish to burden the DX
station with anything other than my call and a 599 meaning "got it".
Please copy,
Derek AA5BT, G3NMX
oo7@astro.as.utexas.edu
>From I2UIY <pcortese@mbox.vol.it> Sun Apr 7 10:43:45 1996
From: I2UIY <pcortese@mbox.vol.it> (I2UIY)
Subject: EUROPEAN SPRINT
--=====================_828870225==_
Content-Type: text/plain; charset="us-ascii"
--=====================_828870225==_
Content-Type: text/plain; charset="us-ascii"
EU SPRINT 1996 - Rules
The EU Sprint Committee hereby invites you to participate in the
four European Sprint Contests held in 1996.
Entrants: any licensed station operating from Europe or outside
Europe may enter the Sprint.
Object: EU stns work everybody, DX stns work only EU
Categories: Single Operator ONLY. Only ONE signal may be aired at
one time.
Dates:
EU SPRINT Spring:
SSB: third Saturday in April - 20 April 1996 - managed by G4BUO
CW: third Saturday in May - 18 May 1996 - managed by B.C.C.
EU SPRINT Autumn:
SSB: first Saturday in October - 5 October 1996 - managed by
I2UIY
CW: second Saturday in October - 12 October 1996 - managed by
OK2FD
Time: from 15:00z until 18:59z.
Bands: 20, 40 and 80 meters only. Pilot frequencies are: SSB:
14.250, 7.050, 3.730. CW: 14.040, 7.025, 3.550
Exchange: all of the following data MUST BE PART OF THE EXCHANGE:
- your callsign,
- the other station's callsign,
- your serial number starting from 001 (RST not required),
- your name or nickname.
Please note that BOTH callsigns MUST be repeated by BOTH
stations.
A valid exchange is: "OK2FD de I2UIY 118 Paolo" while "OK2FD 118
Paolo" is NOT a valid exchange.
Special QSY Rule: if any station initiates a call (by sending CQ,
QRZ?, etc.), he is permitted to work ONLY one station on the same
frequency. He must thereafter move AT LEAST 2 (two) kHz before he
may call another station or before he may solicit again (CQ,
QRZ?, etc.) other calls.
Valid contacts: valid contacts are QSOs correctly logged and
confirmed. Each operator may use ONE and ONLY one name during the
Sprint. If the exchange is copied incorrectly, that operator will
receive zero (0) points. In case of miscopied callsigns, both
stations will receive zero (0) points for that QSO. The Committee
reserves the right to apply penalties in particular cases of
violation of the rules or spirit of the contest.
Scoring: each valid QSO counts one point. The final score is the
total number of QSOs.
Awards: there are NO awards or prizes since these contests have
been created to test the individual skills only. Results will be
forwarded as soon as possible to Leagues, magazines and
bulletins.
Logs: a single chronological log is required. PLEASE SEND US YOUR
LOG ON A FLOPPY DISK. Use any of the available software or send a
plain ASCII file. A separate summary sheet is required too. Logs
must be sent NO later than 15 days after the contest to the
appropriate address:
- Spring SSB Sprint: Dave Lawley, G4BUO, Carramore,
Coldharbour Road, Penshurst, Kent, TN11 8EX, England, UK.
- Spring CW Sprint: Bernhard Buettner, DL6RAI, Schmidweg 17,
85609 Dornach, Germany.
- Autumn SSB Sprint: Paolo Cortese, I2UIY, P. O. Box 14, 27043
Broni (PV), Italy.
- Autumn CW Sprint: Karel Karmasin, OK2FD, Gen. Svobody 636,
674 01 Trebic, Czech Republic.
Logs for ANY of the four events may also be sent by Internet Mail
to "eusprint@dl6rai.muc.de". The receipt of your electronic log
will be confirmed. If you don't receive a confirmation within two
days, try again or use the postal system.
Thanks in advance for your participation de: G4BUO, I2UIY, OK2FD
and the B.C.C. Sprint Committee.
--=====================_828870225==_
Content-Type: text/plain; charset="us-ascii"
[ ] Paolo Cortese, I2UIY / N7PMC / OK8AFL
[ ] P. O. Box 14 - 27043 Broni (PV) Italy
[ ] Phone 0039-385-53203
[ ] A.R.I. HF Contest Manager
[ ] Email: PCORTESE@MBOX.VOL.IT
--=====================_828870225==_--
>From John Brosnahan <broz@csn.net> Sun Apr 7 14:50:47 1996
From: John Brosnahan <broz@csn.net> (John Brosnahan)
Subject: 4-1000 Info Please?
Message-ID: <199604071350.HAA03532@lynx.csn.net>
As the discussion becomes more esoteric, Tom and I have taken it
off-line. I am not a proponent of the super cathode driven
circuitry and have never used it -- just reported what has been
published in the literature. Tom has tried it and had poor
results as he indicates below. Caveat Emptor!
One statement I made was not as clear as it should have been
(something that Tom was quick to question) so I add his off-line
comment and my response for clarity.
--------------------------
>>Adding grid and screen supplies increases the complexity and
>>will move the operating conditions from the Class B region to the
>>Class AB1 region.
>
>Did you mean from AB2 to AB1? The 2 indicates control grid current and the 1
>indicates no control grid current. AB means between 180 and 360 degrees
>conduction angle.
>
I meant Class B as one limit and Class AB1 as the other limit and
the meaning would have been better stated if I had used "TOWARD"
rather than "TO". ie While increasing the biases you can move the
operation point from B (THROUGH AB2) (all the way) "TO" ("TOWARD')
AB1 if so desired.
Guess I thought my meaning was obvious but it is usually my
mistake to believe that others probably think like me! HI
73 John W0UN
----------------------------
>I've never been able to duplicate the result the results claimed in those
>articles. To the contrary, I've found (and other engineers have confirmed)
>IMD increased and stability decreased by following the suggestions in that
>series.
>
>While the original Collins circuit worked very well (I think it was one of
>the best and most innovative designs ever), applying Collin's techniques to
>triodes or class AB2 amplifiers without IMD and stability testing isn't a
>good idea.
>
>If you look at any of the circuits suggested by actual design engineers at
>Eimac, and published in official Eimac data like "Care and Feeding of Power
>Grid Tubes" or in tube data sheets, the "Super Cathode Driven" circuits are
>nowhere to be found. I think that tells us something.
>
>73 Tom
John Brosnahan
La Salle Research Corp 24115 WCR 40 La Salle, CO 80645 USA
voice 970-284-6602 fax 970-284-0979 email broz@csn.net
>From Brian K. Short" <ke7gh@primenet.com Sun Apr 7 15:33:16 1996
From: Brian K. Short" <ke7gh@primenet.com (Brian K. Short)
Subject: More Amp Info: Ameritron?
Message-ID: <01BB248F.2BA3D0E0@ip021.phx.primenet.com>
I appologize for the ongoing amplifier saga, but perhaps I can
summarize at a convenient time...
Someone suggested that I ask about operating Ameritron Amps in
RTTY/contest service. I am curious about anecdotes, stories,
technical information etc regarding using the AL-1200 and AL-1500
amps. I already know 8877's are expensive, but how often do they
fail? What about power supplies, band switches, arcing, etc? How
does an AL-1500 compare to an Alpha 77? How does the AL-1200 and
other similar designs compare?
Your tolerance is greatly appreciated!
73 de Brian
#ifdef HONEST_OPERATOR
#define US_LEGAL_LIMIT (1500.0)
#else
#define US_LEGAL_LIMIT ((double)MAXINT)
#endif
/* Setup Duty Cycle (percentage) */
Amplifier.Duty_Cycle := 100.0;
/* Setup Power Output (watts) */
Amplifier.Power_Output := US_LEGAL_LIMIT;
/* Setup Mean Time Between Failures (years) */
Amplifier.MTBF := Owner.Life_Expectency;
>From AA3JU George Cook <george@epix.net> Sun Apr 7 16:34:06 1996
From: AA3JU George Cook <george@epix.net> (AA3JU George Cook)
Subject: Contest Exchanges
Message-ID: <199604071528.LAA25100@coconut.epix.net>
I would have to oppose the checksum idea big time.
Many of the Q's we get in any contest are those second and third level guys
that have no idea what the contest is but do get on and make 5 or 10
contacts with the loudest stations that they hear. So can you imagine
trying to explain to some 70 year old guy (a nice guy at that) wh just came
home from church on Sunday AM exactly how to determine what his Hexadecimal
checksum is? I have no doubt that Sunday morning contesting would be a
whole new experience.
I think too that if you like long challenging exchanges that the contests
are already in place. Do sweepstkes rather than ARRL DX or CQ.
AA3JU george@epix.net AA3JU@W3PYF
Proudly F R C...........
"FRC When second best just isn't good enough!"
>From Paul Erickson <paul1@wizard.ucs.sfu.ca> Sun Apr 7 17:02:06 1996
From: Paul Erickson <paul1@wizard.ucs.sfu.ca> (Paul Erickson)
Subject: email address for WV0M?
Message-ID: <9604071602.AA21060@wizard.ucs.sfu.ca>
Anyone have the email address for John WV0M? I need to talk to him
about the wpx test.
cheers, Paul
ve7cqk
email: paul1@wizard.ucs.sfu.ca
>From Bruce (AA8U)" <aa8u@voyager.net Sun Apr 7 18:57:40 1996
From: Bruce (AA8U)" <aa8u@voyager.net (Bruce (AA8U))
Subject: DXpedition Location
Message-ID: <199604071757.NAA10350@vixa.voyager.net>
Hello Fellow Contesters,
I am looking for information regarding rentable accommodations compatible
with contesting in the Caribbean or Central America for the '97 contest
season. A location with some antenna supports in place and maybe some
equipment on site would be a plus. Please forward information you think
might assist me in planning for one of the major contests. Thanks in advance
for your advice and assistance.
73,
Bruce (AA8U)
>From Chris & Bill Shell <shell@callamer.com> Sun Apr 7 20:34:04 1996
From: Chris & Bill Shell <shell@callamer.com> (Chris & Bill Shell)
Subject: More Amp Info: Ameritron?
Message-ID: <01BB247E.E4449640@shell>
Brian,
I have an AL1200 that I purchased in 1989. It replaced two homebrew amps
which used 2x3-500Zs and a single 4CX1500B.
Generally, I find the 3CX1200A7 quite rugged. I run it at 1500W near
continuously during DX contests. On RTTY I also run 1500W, but have never
used it during a contest. It does get very hot on RTTY, but with the fan
on the highest (read loudest) of the four settings, it stays at a steady
1500W. This is unlike my 4CX1500, which tended to drop off the longer I
kept transmitting. But that was an old commercial pull that just kept
going.
Overall, I find the single 3CX1200 has been many times more rugged than the
3-500s which only lasted me one to two years before deteriorating to less
than 1500W. I am still using my first tube after 7 years, although, I now
have a spare just in case of a failure. Hi Hi.
The AL1200 can be modified to use a pair of 3CX1200s by adding a filament
transformer, tube socket, chimney, and a few miscellaneous parts. When I
was interested in trying RTTY contesting, I talked with the guys at
Ameritron about it (before the MFJ merger), and they indicated that it
could be easily done. They said it would take a bit more drive to get
1500W output since it would not be quite as efficient. My AL-1200 takes
right at 90W drive for 1500W output.
That is about all I can think of to say today.
73, Bill
WA6IET
shell@callamer.com
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