Four 4-tube Radios

[wa2ise]

Originally Posted by DavGoodlin

AA4 sets in my collection;
A Westinghouse H648T4, Stewart Warner 9180H and Admiral 4L26

I will restore all four and compare them. I was always curious how sensitive these sets would be when the IF amplifier tube and one IF transformer were omitted.

Another omission is AVC, since there is no stage for IF amplification.

The lack of AVC should make for better diode detector performance, as there isn't any backbias from the AVC cap. Also, less tuned circuits (from a lack of a 2nd IF transformer) should make for wider bandwidth on detected audio from strong local stations. If you have a music radio station that's strong enough, and you'd want to listen to, you could modify one of these sets to become an AM tuner to feed a hifi system (of course you need a power transformer to make it safe). Most AM stations broadcast up to 10KHz of audio, but most receivers cut the top 5KHz of audio. Yes, stations are spaced by 10KHz, but not in the same city.