Congrats on the Alpha 78. A word to the wise, keep the grid current under
50ma and run the amp very conservatively because the 8874's are very
expensive to replace. My 78 (serial # 8271)puts out 1200 watts and that's
enough.
Bob W6TR
----- Original Message -----
From: "Frank N. Haas" <headrat@rats-computers.com>
To: <amps@contesting.com>
Sent: Tuesday, September 27, 2005 1:58 AM
Subject: [Amps] Suggestions for new Alpha Owner?
>
> Greetings Amp'ers:
>
> Today I fulfilled a long time dream. I now own a real Alpha HF power
> amplifier.
>
> A ham within 1 hour driving time recently offered his Alpha 78 for sale at
> a price I could afford. When I read his ad I immediately called him and
> arranged to visit and examine the amp. It's cherry and works perfectly.
> Serial Number 8355 with the Low Power Mod and an SO-239 on the RF Input.
>
> I got it home, connected it and proceeded to make contacts on 75 SSB and
> 40
> CW. Great signal reports. Good clean signals on both modes. Testing into a
> dummy load, the amp easily produces up to 2 KW output on 80 through 15
> meters with grid current well below 50 ma. I couldn't be happier.
>
> Prior to visiting and buying the amp, I downloaded the manual and searched
> the web for info on this model. I didn't find much. By most accounts it's
> possibly one of the best amps ever made. Sure the tubes are expensive and
> are on the verge of being discontinued but if the legend is true and I
> don't abuse the amp, the tubes should last nearly forever.
>
> So what suggestions do you have for a new Alpha owner?
>
> Some I've read so far in my research:
>
> Annual cleanings
> Monitor the Grid Current
> Keep the load SWR 1.5 to 1 or less
> Keep the chimneys and anode vents clean
>
> Are there others?
>
> I have been using a Heathkit SB-221 with much success for quite a while.
> It
> experienced the dreaded Glitch and blew a tube. I added Harbach mods and I
> don't worry about such things any longer. Is the Alpha subject to the same
> Glitch problem??? I did read where 24 MHz is not recommended because of a
> HV plate choke resonance issue at 25 MHz.
>
> Are there other mods recommended?
>
> I await your advice.
>
> Respectfully,
>
> 73,
>
> Frank N. Haas KB4T
> Florida
>
>
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