03-12-2013, 12:48 PM
Dave
1. Do NOT, and I repeat, do NOT turn it on by plugging it in the Mains if you had not make sure by now you can do that.
2. I strongly recommend you fully recap the radio, but as a minimum you should change EVERYTHING capacitive in the rectifier filter section.
3. First use a Variac to bring it up, use voltmeter and see if the voltages make sense, even if they are not 100% the same as the charts show.
4. Do the smoke test - bring it up very quick, with the voltmeter on the rectifier output, make sure the voltage rise is not impeded and it goes where it should, bring it back to Zero.
5. Take a breather, let the heartbeat go back to 70 beats per minute, then repeat the experiment and wait for a minute or so, waiting for the smoke to appear. if nothing smokes - you have passed the smoke test.
6. Now you can do the troubleshooting.
Start from here.
PS. Before you start - check your cord for cracks, check the radio with the Power Switch in "ON" position with the Ohmmeter across the Mains plug for a dead short. Turn it Off, see if the continuity disappears.
It does not hurt to check the continuity of the transformer for every winding. If you are really anal, desolder every winding and see if there is a short across the load.
I do not do this but I have enough experience to react quickly if something happens, and I kinda know what bad things one could expect.
In short: This is a TUBE radio, there are high voltages, it is powered from Mains and there can be consequences to your health and property if the due respect is not paid.
Be safe.
1. Do NOT, and I repeat, do NOT turn it on by plugging it in the Mains if you had not make sure by now you can do that.
2. I strongly recommend you fully recap the radio, but as a minimum you should change EVERYTHING capacitive in the rectifier filter section.
3. First use a Variac to bring it up, use voltmeter and see if the voltages make sense, even if they are not 100% the same as the charts show.
4. Do the smoke test - bring it up very quick, with the voltmeter on the rectifier output, make sure the voltage rise is not impeded and it goes where it should, bring it back to Zero.
5. Take a breather, let the heartbeat go back to 70 beats per minute, then repeat the experiment and wait for a minute or so, waiting for the smoke to appear. if nothing smokes - you have passed the smoke test.
6. Now you can do the troubleshooting.
Start from here.
PS. Before you start - check your cord for cracks, check the radio with the Power Switch in "ON" position with the Ohmmeter across the Mains plug for a dead short. Turn it Off, see if the continuity disappears.
It does not hurt to check the continuity of the transformer for every winding. If you are really anal, desolder every winding and see if there is a short across the load.
I do not do this but I have enough experience to react quickly if something happens, and I kinda know what bad things one could expect.
In short: This is a TUBE radio, there are high voltages, it is powered from Mains and there can be consequences to your health and property if the due respect is not paid.
Be safe.
