Four 4-tube Radios

[DavGoodlin]

After a friend asked me to restore a 1954 GE model 419 - brown plastic with 4 tubes, I realized there were 3 more untested 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. I also wonder if there were distant regions in which these would not work during daylight hours or where AA4s just were not sold at all.

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

What is really odd is that the Stewart Warner has no loop but a long wire antenna and uses a 12BE6 instead of the 12AU6 as the other three do.

The first to be recapped is the Stewart Warner. Four paper caps, two electrolytics and three out-of-tolerance resistors were replaced. Using a signal generator per Sams schematic, I tweaked the one IF trans for 455kC, oscillator coil and both trimmers. The night reception with a 10 ft wire got only one local station, but I first tried it on a 30 foot outside wire, got pretty decent reception of the usual distant stations, for example; WBBM 780, WJR 760, WKBW 1520* and a few Canadian stations. The sound was pretty good as well.

* This radio came from Buffalo, no surprise this was the first station it picked up

I will post pictures as I work on the others.