Collins 75A 4 Receiver After Refurbishing

Another demo of a Collins 75A-4 receiver after refurbishing, including SSB and CW reception on the 40M ham band and AM reception at the upper end of the broadcast band, controls function testing and demos of the PTO/tuning dial accuracy after 15 minutes, and again after 1 hour warm-up periods.

[@richlevenson6605]

One helluva receiver. My cousin Norman (W1HOL - SK) had this with all the filters. Used to love listening to it as well as
tuning around the 20-meter band. Still such a sought-after radio. That will never change. Nice presentation - Rich, W2FKN

[@RadioRestoration]

Yes, its a real pleasure to use!

[@richardross3815]

Well done as usual Gerry. She’s a real beauty. Not an Eddystone of course… but still nice. Lol

[@RadioRestoration]

Thanks Richard. I was thinking it must be about time I found another interesting Eddystone set to work on - problem is that friends I have that own them are more than capable of working on them themselves, and I don't want to start buying and collecting boatanchors again, having divested of most of my collection as part of my 'downsizing' efforts. Hmmmm - I need to think of a new strategy....

[@dieselten01]

Beautiful radio, excellent refurb! Thanks for sharing

[@RadioRestoration]

Glad you like it. The matching KWS-1 transmitter and power supply are waiting to be refurbished later in the summer/Fall. These are also in excellent condition.

[@mikeerstad3705]

Beautiful Receiver Gerry.....I have one just like it,,,,,,I;m missing the 3rd "C" filter under Selectivity..... Thanks for the demo.....Mike

[@RadioRestoration]

Hi Mike. The owner of this set told me he bought the 6KHz filter as it was missing also - its a 'Longwave Products' part and works well

[@rodleger7132]

I have my Dad's 75A-4 from the 1950's.
I have recapped. Need to finalize the procedures.

[@RadioRestoration]

Have fun Rod - these sets are quite straightforward to align.

[@mikebracey8832]

Very nice.

[@RadioRestoration]

Indeed - the owner is a very lucky man (and who also owns the matching KWM-1 and power supply - that I have yet to refurbish)

[@union310]

Can I ask what the refurbishment involved please .

[@RadioRestoration]

In summary, replacing all paper and electrolytic capacitors, checking resistors/replacing four out of tolerance resistors, testing tube/replacing weak/failed tubes, cleaning switch contacts and controls and realignment. If you are on Facebook, you can read my blog that details all the work done: facebook.com/gerrysvintageradio/ . I am also preparing an article that will be posted to the SPARC Radio Museum website.

[@union310]

@@RadioRestoration That's fantastic, well done Sir.

[@RadioRestoration]

@@union310 I forgot to add that I also changed out several silver mica capacitors that are known to give problems, plus one in the 11M 1st local oscillator circuit that had an intermittent

[@union310]

@@RadioRestoration I am a model engineer in my spare time, I build all sorts of stuff from locos to traction engines and clocks as well as machines to that. I have always had an interest in Ham radio and have recently passed my foundation level. I made myself a Morse key last weekend, a little different in places but it works well as well as looking nice in Oak and brass. The aspirations are to pass they next two levels and build a transceiver.

[@RadioRestoration]

@@union310 All the best with the ham exams. I was G8GUH in the UK (licensed in 1972!), VP8BDE in the Falklland Is (mid-1980's)., and now VE7GUH in Canada

[@robertcros9488]

Military technology

[@RadioRestoration]

At least its application to a high-end ham bands only receiver!