- 2024
- Apr
- 20
A Radio Shack 28-177 Crystal Radio Kit
This kit used to be a staple of Radio Shack’s lineup. It’s nothing more than a simple crystal radio kit with a tuning capacitor, ferrite bar antenna coil, and a 1N34 or equivalent diode on a simple plastic cased paper breadboard. The plastic chassis was reused for many things, as evidenced by the battery holder on the bottom, and the multitude of devices that were presented in the catalog.
This particular example is brand new. First thing to do is inventory all the parts, and they’re all here in 3 bags.
1 - Spring terminals and free candy.
2 - Ferrite bar, earpiece, antenna wire, and diode.
3 - Capacitor, knob, wires, and screws.
The chassis and manual complete the parts included. You’ll need a piece of wire for a ground - the manual suggests using part of the antenna wire. I had some 18ga primary wire in my toolbag, I used that for this test instead.
Assembly really only takes about 15-20 minutes. Punch out the holes for the springs, install them, then the diode, tuning capacitor and ferrite bar.
The only issue here was determining what wire on the ferrite bar’s coil went where. The color on the white and yellow wires was somewhat faded from years of storage. There was just enough left that, with some close-up examination, I was able to determine where they went.
Assembly was finished, with just the antenna, ground, and earpiece to add.
(The ground wire was connected after the picture was taken. It went right to the earth of the building I was in.)
Unfortunately, the area I was in didn’t have any strong AM stations around, so there was nothing to listen to. I was able to get some electrical noise on the earpiece, so it’s at least working. I was going to demo the device connected to a signal tracer, but that’s going to wait until I can get to a location with better signal strength.
Stay tuned!