4-1000 Info Please?

W8JITom at aol.com W8JITom at aol.com
Sat Apr 6 23:21:26 EST 1996

Hi John,
In a message dated 96-04-06 12:32:24 EST, you write:

>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

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 at adams.net (jim funk)  Sun Apr  7 05:29:50 1996
From: jfunk at adams.net (jim funk) (jim funk)
Date: Sat, 6 Apr 1996 22:29:50 -0600
Subject: 599s
Message-ID: <9604070429.AA30399 at 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 at s55tcp.ampr.org>  Sun Apr  7 10:25:42 1996
From: Marijan Miletic <s56a at s55tcp.ampr.org> (Marijan Miletic)
Date: Sun, 07 Apr 96 05:25:42 EDT
Subject: Tetrode QRO
Message-ID: <12652 at 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 at primenet.com (Tony Rogozinski)  Sun Apr  7 07:35:17 1996
From: trogo at primenet.com (Tony Rogozinski) (Tony Rogozinski)
Date: Sat, 6 Apr 1996 23:35:17 -0700 (MST)
Subject: DG tells us how to talk
Message-ID: <199604070635.XAA18759 at 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
>I LIKE IT! Kinda like 5nnt5 on cw, right?  LET'S DO IT.   de Doug KR2Q  :-)
I like : .  -.  -.  -.  -.   (ARRL CW) better.   



                                Tony Rogozinski N7BG
                                VooDoo Contest Group
                                 trogo at 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 at astro.as.utexas.edu (Derek Wills)  Sun Apr  7 08:38:46 1996
From: oo7 at astro.as.utexas.edu (Derek Wills) (Derek Wills)
Date: Sun, 7 Apr 1996 01:38:46 -0600
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 at astro.as.utexas.edu

>From I2UIY <pcortese at mbox.vol.it>  Sun Apr  7 10:43:45 1996
From: I2UIY <pcortese at mbox.vol.it> (I2UIY)
Date: Sun, 07 Apr 1996 09:43:45 +0000

Content-Type: text/plain; charset="us-ascii"

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.

SSB: third Saturday in April - 20 April 1996 - managed by G4BUO
CW:  third Saturday in May - 18 May 1996 - managed by B.C.C.
SSB:  first  Saturday in October - 5 October 1996  -  managed  by 
CW:   second Saturday in October - 12 October 1996 -  managed  by 

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 
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 

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 at 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.
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


>From John Brosnahan <broz at csn.net>  Sun Apr  7 14:50:47 1996
From: John Brosnahan <broz at csn.net> (John Brosnahan)
Date: Sun, 7 Apr 1996 07:50:47 -0600
Subject: 4-1000 Info Please?
Message-ID: <199604071350.HAA03532 at 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
>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 at csn.net

>From Brian K. Short" <ke7gh at primenet.com  Sun Apr  7 15:33:16 1996
From: Brian K. Short" <ke7gh at primenet.com (Brian K. Short)
Date: Sun, 7 Apr 1996 14:33:16 +-100
Subject: More Amp Info: Ameritron?
Message-ID: <01BB248F.2BA3D0E0 at 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 

#define US_LEGAL_LIMIT (1500.0)
#define US_LEGAL_LIMIT ((double)MAXINT)

/* 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 at epix.net>  Sun Apr  7 16:34:06 1996
From: AA3JU George Cook <george at epix.net> (AA3JU George Cook)
Date: Sun, 07 Apr 1996 11:34:06 -0400
Subject: Contest Exchanges
Message-ID: <199604071528.LAA25100 at 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 at epix.net    AA3JU at W3PYF
Proudly  F R C...........
"FRC When second best just isn't good enough!"

>From Paul Erickson <paul1 at wizard.ucs.sfu.ca>  Sun Apr  7 17:02:06 1996
From: Paul Erickson <paul1 at wizard.ucs.sfu.ca> (Paul Erickson)
Date: Sun, 7 Apr 96 9:02:06 PDT
Subject: email address for WV0M?
Message-ID: <9604071602.AA21060 at wizard.ucs.sfu.ca>

Anyone have the email address for John WV0M? I need to talk to him
about the wpx test.

cheers, Paul
email: paul1 at wizard.ucs.sfu.ca

>From Bruce (AA8U)" <aa8u at voyager.net  Sun Apr  7 18:57:40 1996
From: Bruce (AA8U)" <aa8u at voyager.net (Bruce (AA8U))
Date: Sun, 7 Apr 1996 13:57:40 -0400 (EDT)
Subject: DXpedition Location
Message-ID: <199604071757.NAA10350 at 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.

Bruce (AA8U)

>From Chris & Bill Shell <shell at callamer.com>  Sun Apr  7 20:34:04 1996
From: Chris & Bill Shell <shell at callamer.com> (Chris & Bill Shell)
Date: Sun, 7 Apr 1996 12:34:04 -0700
Subject: More Amp Info: Ameritron?
Message-ID: <01BB247E.E4449640 at shell>


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 

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
shell at callamer.com

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