The Stovebolt Site Forums The Shop Area The Electrical Bay The Radio Bench I have noise

I put in the new vibrator and now I have a hum that I can control with the volume knob. I will have to check my solder joints and look at some voltages tonight. If it was 1968 I would take the tubes to the local Totsum store and check them. I guess I can bring home the scope and see what I have going on if the Simpson and some voltage checks don't clue me in. At least now I have an output to play with.

Neilroy,
you might want to have a look at the thread "New Stovebolt Radio", below. I went through a technique there that can save you a lot of time. Congratulations on your excellent signs of life!

Well I have determined that with the output of the OZ4 disconnected I have 280 volts with a load it drops to 122 volts. I guess now the hunt is on to see what is loading it down. My B+ on all of the tubes is about half of what it should be. I will check out the thread.

Neil,
if this is similar to the AD radio, you should have a resistor between the two main filter capacitors. Is your voltge low for both these points? Also,if you are using a trickle charger, the radio may be starving for current. If it is a 6/12V trickle charger, you could flip to 12v for mabe 30 seconds to see if your radio responds.

Fred

It looks like my charger is only putting out about 2.8 amps. I am going to see if I can find a better power source. I also had swapped my leads on the filter capacitor and opened up the 20 mf @ 25 volt part. That wasn't good. Even after color coding the leads with heat shrink. Now I get to pull it back out. I have 4 of the 20mf @ 450 volts but none at 25 on hand. Thanks.

Neil,
you can use the higher rated 450V capacitor. It is just takes more space. That is the voltage at which the capacitor will break down.

I already tagged one on the bottom and will probably not worry about pulling the can back apart. I think I am going to build up that regulator circuit for 12 to 6 volts and see how that works out for power.

I built up the 12 to 6 volt converter. The increase in current got my regulated voltage up to 186 volts. Still a problem somewhere but the regulator circuit seems to be a good under $20 deal. I have hit the mother load with one of my old TV station engineering buddies he has a tube tester and a huge selection of tubes. Hopefully I can have the tubes tested and get some tubes from him. I sent him a schematic and he looking for replacement tubes.