Jerry,
Welcome to the "old Alphas owners group".
If you think the 78 is heavy, try a 77. Yikes. ;-)
Suggestions:
(1) Put a reverse-biased rectifier diode between collector and emitter
on that transistor switch. You just never know what you're going to hook
it up to next, and relays can have a pretty good inductive kick.
(2) Gently bead-blast the cover, then find a friendly powder-coat shop
that will put wrinkle black on it. $50-$75 would be a good price.
You remind me that I have a 76A that's been waiting for me to put caps
in it for a couple of years now. [sigh]
Congrats and 73,
Jim N7CXI
On 6/18/2012 5:39 PM, Jerry Kaidor wrote:
> Back from the Frigid North ( about 1 hour north of the QTH ),
>
> I have the Alpha 78 in hand. Works fine. We had a moment of panic
> when the seller powered it up with the top cover off. Flash went the
> HV fuse!
> First impressions:
>
> * This thing is a beast. O my aching back. It's also physically large,
> and visually overpowers the rest of the station. But it "feels" like
> a piece of commercial equipment that won't need to be babied.
>
> * The blower is a little louder than I'd like. I see RF Concepts has
> new blowers, not too expensive...
>
> * I'm not sure if I like the verniers on the plate and load caps. I
> like to tune *fast*. On the 30L1, I even turn off the transmitter
> between trying load values. Try a load setting, give it a toot of RF,
> and dip. Let it rest, try another value, another toot of RF & dip.
>
> * It's got a couple of big scratches on the top cover. And several
> missing top cover screws. That's OK, the top cover doesn't worry me
> much. Scratches on the front panel OTOH would be a big deal. The top
> cover can easily be repainted. RF Concepts has a complete set of screws
> for $5...
>
> * There's an elaborate QSK system that I don't understand yet, and might
> not use.
>
> * It's going to be easy to switch the PTT. The PTT voltage is positive
> 21.5 volts, and when you ground it to transmit, you only need to sink
> 2.5mA. I'm thinking a 2N3904, a resistor, and a few bypasses.
>
> - Jerry Kaidor ( jerry@tr2.com )
>
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>> Hi Guys,
>>
>> I have come to an agreement to buy an Alpha 78 from a local ( 1.25 hour
>> drive ) guy. Will probably drive out there to pick it up today.
>>
>> - Jerry Kaidor
>>
>>
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>>
>
>
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