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[AMPS] Benefit

To: <>
Subject: [AMPS] Benefit
From: (km1h @
Date: Sun, 15 Mar 1998 16:17:10 EST
On Sat, 14 Mar 1998 22:51:40 EST KA2YKC <> writes:
>In a message dated 98-03-14 11:56:21 EST, you write:
><< I assume that is with zero reflected power? Seems a bit hard to 
> with only 60W of drive.  What is your key down Ep and Ip at this 
> Rich, myself and others have tried to explain since the beginning of 
> reflector that the AL80xxx manual is a study in irresponsible 
> To tune to 550ma plate and 200ma grid is asking for a very poor SSB
> signal. I would urge you to obtain a copy of the Eimac/Amperex spec 
> and follow their reccomendations, not MFJ/Ameritron. 
> At 2700V Ep,  130ma Ig and 400ma Ip you should obtain around 650-700W 
> output, add 12-15% for PEP. BTW, on SSB the peak Ip meter reading 
> not exceed 250-300ma, even with processing.  That will keep the rest 
> us on the band happy also.
> 73  Carl  KM1H >>
>I seem to recall getting around 900-1000w on a Bird 43 on 20 meters, 
>with a
>low swr. However, one minor difference in the numbers quoted above was 
>Plate voltage, which was around 3300v or so. I would guess that may be 
>case with his AL80B.
>Eric KK2ED

Eric, I never said that you can't get a KW out...what I am saying is that
in order to do that on SSB you will have a very dirty signal.
If the 80B version (I was reading from the 80A manual) runs at 3300VDC
key down the Ip should STILL not exceed 400ma...that is 1320W input.
Assume 60% average efficiency 160-10M and we have roughly 790W CW output;
add 12% for PEP and you have almost 890W at the absolute modulation
crest...not what you read on over the counter power meters. This is fine
and is also what others have recommended...not 1000-1200W SSB as claimed
by Ameritron.  There is no amount of magic or advertising BS that will
change it.

The AL-80 series are reasonably decent amps when operated in "accordance
with good engineering practices".  Read the March QST editorial.

73  Carl  KM1H

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