Re: Wonderbar radio operation

Posted by humanpotatohybrid On 2023/12/18 18:09:57

Currently I have been bench testing it with a switching power supply which garbles up the output. I will test with a fuse and battery later.

Perhaps the trigger tube was going bad? With new caps, new tubes, and polished contacts there is very little that could cause a problem unless it was pulled out of a swamp or something. The trigger tube monitors the AVC line to get the current signal strength. When the AVC line is pulled low enough (strong signal) the trigger tube reduces its amplification. Instead of amplifying an audio signal it "amplifies" the power available to the solenoid that keeps the tuner from stopping its progression. Less amplification = less power for the solenoid, and it releases the catch to stop the autotuner.