The Stovebolt Site Forums The Shop Area The Electrical Bay The Radio Bench Excellent, another radio to play with

project update
Today will be two posts to fit more photos. Almost complete!

I Resolved the few minor issues found in the test fit. Increased the Tone wires by a couple inches and the tuning clutch was a bit looser than i liked, it measured 0.022 at open, i reduced that to about 0.018 and it feels better.

I like using old rusty tubes that i don't care about for the initial power up and DC checks.
I get the fancy glass tubes with GM Genuine Part markings once i know the radio won't burn any out.
Some of the old tubes had some rusting on the metal base, soaking them in evaporust and rinsing them off with alcohol got them looking good.

The initial power up test revealed excessive current draw which i traced to the speaker wiring, I wired up the plug "top view" by accident, my notes were written with "bottom view" pinout. Fortunately this error didn't cause any permanent damage and was an easy fix.

The alignment procedure was a bit more painstaking because I didn't have my AM signal generator in California.
To do the alignment i used a simple function generator outputting a pure sine wave at the specified frequency.
Then instead of looking at the demodulated tone at the 6V6 i check the carrier or IF with an oscilloscope.

Before the unit is aligned it will (should) pick up radio stations and sound reasonable, however you may notice that the unit is more sensitive and picks up the weak stations better post alignment; for this particular radio it was very noticeable, the AM band had more usable station after it was aligned.