Restoring the Heathkit Jr 35
|Heathkit Jr Electronic Workshop "35", Model JK-18|
The Heathkit Jr 35 evidently had been stored with batteries in the battery holder, which corroded badly. I replaced it with a plastic RadioShack 4 D-cell battery holder (270-389), wired into the negative power rail and the hot side of the power switch (which is part of the variable resistor).
|Corroded battery holder|
|Replacement battery holder mounted|
|The remote speaker station|
The rubber foot used to protect the relay from being crushed when you turn the kit over was stuck to the remote speaker station. I put it in its rightful place.
|Relay with the brown rubber foot|
I ran through the tests in the manual appendix to check out the lamp, power switch, speaker, earphone, antenna coil continuity, remote station speaker & telegraph key, slide switch, and relay.
I then jumped ahead of myself, building the 4-transistor AM radio experiment; I got slight hints of a audio signal if I wiggled and touched some of the wires. I'm highly suspicous of the electrolytic capacitors. I probably should have tested those (and the transistors) before using them in such a complex circuit. The wire connections to the springs are not all that reliable, and the wires might have some oxidation on them.