When operating DR1A I do as well, but release it on pauses.
73
Peter
-----Original Message-----
From: amps-bounces@contesting.com [mailto:amps-bounces@contesting.com] On
Behalf Of Carl
Sent: Mittwoch, 4. April 2012 18:32
To: Peter Voelpel; amps@contesting.com
Subject: Re: [Amps] amp cooling / triodes vs tetrodes
Many use a foot switch
Carl
KM1H
----- Original Message -----
From: "Peter Voelpel" <df3kv@t-online.de>
To: <amps@contesting.com>
Sent: Tuesday, April 03, 2012 10:31 PM
Subject: Re: [Amps] amp cooling / triodes vs tetrodes
> Why should one care about an amplifier without EBS or high idle current at
> all?
> That current is only drawn if actually transmitting and not in standby
> mode
> without output power.
>
> 73
> Peter, DJ7WW
>
> -----Original Message-----
> From: amps-bounces@contesting.com [mailto:amps-bounces@contesting.com] On
> Behalf Of Jim Thomson
> Sent: Dienstag, 3. April 2012 17:46
> To: amps@contesting.com
> Subject: [Amps] amp cooling / triodes vs tetrodes
>
> Date: Mon, 02 Apr 2012 12:59:10 -0700
> From: Jim Barber <audioguy@q.com>
> Subject: Re: [Amps] amp cooling / triodes vs tetrodes
> Leigh,
>
> Not to drive everyone up a tree with this topic, but do you know of any
> non-proprietary designs that might serve at least as a basis for a
> properly-done EBS implementation?
>
> I'm not thinking so much of modifying my (newest) commercial amp, but I
> do have a YC156 project that seems to be in eternal overhaul, as well as
> a Henry 3KA that could benefit from such a beast.
>
> Along that line I also (still) have one Alpha 77 left with their EBS,
> but I'm not sure I'd qualify that one as more than a good start at
> "properly done", at least by today's standards. (It's from before they
> added the control pot, early design)
>
> Thanks,
> Jim N7CXI
>
> ### You can buy the entire TRI-state EBS from the Ameriton catalog.
> They have 1-2 versions of it. Complete, ready to go.
> It might need some tweaking to obtain higher V levels for a YC-156.
>
> ## I dunno why you would want to mess with EBS....if you use VOX on SSB.
> You don't need to suck 350 ma of idle current on a YC-156. 150-200ma is
> plenty.
> 150 ma idle on a 3CX-3000A7 triode is plenty for superb imd .
> 150-200 ma idle on a 3CX-6000A7 is ample for good imd.
>
> ## On CW mode, there is NO reason at all to suck
> 150-350 ma of idle current !!!! On CW, just crank up the bias V..until
> the
> idle current is down to 10-20ma. Use a string of series 1N5408 or 6A10
> diodes
> for this job.. and or... a single wire wound resistor. On CW..with
> any
> GG triode
> you can not run the idle current at zero ma...or you will get key clix.
> With 10-20ma
> you wont get any at all. Tank eff will be improved a whole bunch too.
> Your
> idle power
> will be so low, it's a non issue.
>
> ## EBS, even tri-state is a fubar way to go on CW..and also FM.
>
> ## EBS, if using PTT SSB is ok..and saves heat. If using VOX on ssb,
> the ebs will
> not buy you much for heat savings at all. The only time it kills heat is
> between when you
> stop talking..and when the VOX drops out. The EBS is NOT gonna be fast
> enough to toggle
> between syllables !
>
> ## If you want to see something really stupid, check out the 3 x hole
> tetrodes from QRO, etc.
> They idle at a whopping 750ma ! The 2 x holer idles at 450 ma (225 ma
> per tube)
> Using the 3 holer with the same plate xfmr as the 2 holer is even more
> silly. If any
> sb-220 etc, sucked 750ma, it would burst into flames.
>
> ## sure the small tetrodes can be driven with 10-20 watts. Who cares.
> The typ xcvr puts out
> 100-250w these days. You run a 200w xcvr at just 20 watts out..and the
> eff
> goes straight to hell,
> and ditto with the TX imd. You really require a good 3-9db pad to run
> those low power tetrodes
> properly..when driven from your typ xcvr.
>
> Later........ Jim VE7RF
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