[SCCC] Alpha 78

[Michael Tope]

----- Original Message ----- 
From: "Glenn Rattmann" <k6na at cts.com>
To: "Rick D" <n6pe at pacbell.net>; <sccc at contesting.com>
Sent: Monday, January 22, 2007 5:54 PM
Subject: Re: [SCCC] Alpha 78


> Rick,
>
> The Jennings RJ-1A relay new is probably $150 or so; check with Alpha
> if you haven't yet (your amp uses the 24 VDC version).  If you want
> to try the cheaper method, you can get surplus RJ-1A pulls from
> medical equipment from Alan Bond at Max Gain Systems in Georgia.  He
> has a website:
>
> www.mgs4u.com/
>
> Call and ask him about the relay, I think they might be about $45 or
> so if you want to try a used one.

I had good luck with one of those Alan Bond RJ-1A relays that I put in
one of the W6UE Alpha 78's

>
> On the gummy paint-- good luck.  Alpha has newly painted front panels
> (using modern hard paint) for $130 or so.  I was thinking of getting
> a new panel to replace my nasty 76A panel on my old original
> box.  Wonder if they give "core credit" for sending in the old metal
> panel; seems like it ought to be worth something to them compared to
> knocking out new metal work...?
>
> I heard long ago that Dave Ritchie, formerly of this club but now
> living up north somewhere had redone some Alpha panels locally in the
> LA area and it was much cheaper.  Maybe W4EF remembers that....

That was before my time, Glenn. I think Dave just changed his email,
so he might be off the list now (I am cc:ing him).



> Regarding tubes-- I don't know of a specific tube mod other than the
> pair of 3cx800 mod that is offered by Dick at:
> www.N4UQ.com

Here is another site I stumbled on to recently:

http://www.kk5dr.com/alpha76/OLD76.pdf

This OM is suggesting the RF Parts RFC-3 plate choke as a
replacement for the stock Alpha 78 choke to fix the 12 meter resonance
problem inherent in the stock choke. As I understand it, the RFC-3 is the
same choke the Ameritron uses in many (if not all) of their HF tube
amplifiers. I am going to try that one of these days (if I ever get my life
back from work).

And of course my half-baked and much in need of updating Alpha 78 page:

http://www.dellroy.com/W4EF's-Ham-Radio-Page/Alpha78/Alpha78.htm

73, Mike W4EF........................

> If I were keeping the amp for a few more years, and doing a mod, I
> would do it that way I think.  Not cheap but you end up with two of
> the modern tubes, and don't have to look for 3 of the 8874's.  I have
> a friend in the Bay area who had it done by N4UQ and he was happy.
>
> Good luck and let us know how you proceed, I'm sure there are other
> Alpha 78/76 owners on here who might be interested!
>
> Glenn K6NA
>
> At 08:37 AM 1/22/2007, Rick D wrote:
>>Hi all,
>>
>>My old original Alpha 78 will not QSK and I suspect the vacuum relay
>>is shot. Is there a cheap replacement or a solid state mod floating 
>>around?
>>
>>It is a 3 hole and the 8874s are original.  I've seen some
>>replacement mods, but the replacement mods are almost as much as
>>Russian 8874s.  Is there a good mod using some easy to get cheap
>>tubes. Even if it is less power it is OK with me. Seems like I could
>>buy a new Ameritron for what it will cost to fix this one.
>>
>>Also, anyone have an easy fix for the gummy paint these things develop.
>>
>>Thanks
>>
>>Rick Darwicki  -= N6PE =-
>>=================================================
>>17775 Elmhurst Circle
>>Yorba Linda, CA 92886
>>
>>http://www.qsl.net/n6pe/