5-tube commercial radio (T1619E)

This commercial superheterodyne receiver was found in a 1949 Radio Electronics. The circuit uses battery.

15 V Regulator MC1539 (CB19674E)
The circuit is from the MC1539 manual, an operational one close to the 741. The transistor admits...
CB7437E Dummy load for transmitters testing ()
This circuit was found in an American documentation from the 90's. The circuit is intended for...
Telephone Recording (CB24587E)
This telephone recording circuit was found in the June 1979 issue of Radio Electronics magazine. The...