[Collins] 75A1 Modifications or inhancements

[Dr. Gerald N. Johnson]

Its single conversion on the lowest band, so make that work first.

With it open, put a finger on the wiper of the volume control. If the 
speaker buzzes, the audio section is working. If not, be sure the 
speaker is hooked up and go from there. Check the power supply voltages 
with a meter, not a wet finger. Remember tubes are in sockets because 
they are expected to need changing. But when you change IF and RF tubes, 
you need to do an alignment which can get touchy with old ceramic 
trimmer capacitors.

As for upgrades there probably were many published in the ham magazines 
back then, things like different mixers.

73, Jerry, K0CQ, Technical Adviser to the Collins Radio Association.

On 4/3/2010 9:41 PM, BUDW2GLN at aol.com wrote:
> I just recently purchased an early serial (441) 75A1 and I am looking for
> any information that I can gather in order to help me, after I bring it to
> life  :-), perform ANY upgrades along with "things to be aware of" in an
> effort  to help bring this beautiful Collins receiver up to par..... I have an
> excellent Copy of the manual and a copy of the Sam photo fact......After
> bringing it up slowly for most of the day the unit is dead.....I don't think
> that I will have any problem with the general purpose troubleshooting
> But...........If there is any downloadable information out there in that vast
> hyper space :-) I surely could use it.....
>
> Thanks
>
> 73
>
> Bud
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