Yes, My Radios And I Are Still Here.....

 Again, my apologies for another long lapse since my last entry. I can't say it is because I am too busy. On the contrary, being retired and keeping to myself at home during a pandemic, I have way too much time on my hands, but my hands don't seem to find their way to the keyboard. I have become physically and mentally lethargic. Nevertheless, here I am and my subject choice probably won't move you, but more likely put you to sleep.

 My primary distraction is my hobby of collecting and refurbishing vintage radios, both tube and transistor. The years range from 1936 to 2004, presently. Time passes very swiftly while tinkering in my workshop! In this entry, I am going to show you some of the process of resurrecting a radio. "Oh joy!" you are probably thinking. Not to worry, the pain will pass.

This particular set (Emerson 710B) has serious case problems, as you can see. Repairing this case would be a whole story on its own so I will save that for another day. There are cracks on the front and bottom.

 So today I shall focus on repairing the innards.

The first thing to do is give it a test. Not knowing the history of an old radio, it is best to use an isolation transformer and variac. Because many old sets have the metal chassis connected to one side of the two conductor power cord, it can be a shock hazard so the isolation transformer comes into play. And because the components are old and possibly unstable or shorted, a variac is used to gradually bring up the voltage while monitoring the current being drawn. If it hums loudly, the filter caps are bad, if nothing happens, maybe a tube but more likely something else. I rarely find bad tubes. Sometimes other capacitors are bad but they all get replaced anyway. Sometimes a bad resistor, sometimes a bad coil. Here is mine, built on a cake pan:

 Back view, before and after:

Front view:

Top view:

Bottom view:

Various stages:

A 'whoopie pie' nearby is a very important factor:

 

 

That's about it, of course it needs testing when it is done. Sometimes they come up nicely, sometimes not. Further troubleshooting is necessary. Could be a resistor or coil problem. More often than not, it is a wiring error, hmmm, who did that?

Hope you find this meandering interesting!

• The mystery of life is certainly the most persistent problem ever placed before the thought of man. . . . . . The inability of science to solve it is absolute. This would be truly frightening were it not for faith.                    - Guglielmo Marconi