Wednesday, September 30, 2009

Radio working

Thanks to a fresh shipment of parts, I have resurrected the aformentioned Star Roamer radio. I replaced the large electrolytic caps in the power supply section with nice modern ones which don't dry out. I also bypassed the old selenium rectifier in there, as although it was still rectifying, I read reports of them failing by releasing nasty fumes at you. The modern equivalent is a silicon diode, which can cost upwards of 4 cents each.

The other items that had stopped working since the 60s were all the slide switches that operate things like Auto Noise Limiting, On/Off etc. There were four of them, and they all had intermittant connections; it's weird why such a simple device would fail like this. Perhaps I'll autopsy one of them. Anyway, they still make them, and now it has four new ones.

I rigged up an antenna wire, made from old network cable, around the ceiling and switched on. After waiting a short while for the tubes to warm up I heard a light crackle. I had the band on AM and expected to get something, but the were no stations coming in. But when I switched to one of the three(!) shortwave bands I could hear all sorts of stuff; Canadian, South American, even Italian and Russian programs. I think I heard Chinese once. On later investigation, I found the problem with AM - there was a short on the tuning coil. So all I need to complete this radio now is a replacement signal strength meter, which was missing from the kit, and was probably used to fix another radio...