Emerson 547A My first radio project from start to finish, and what I learned.

I just finished up an Emerson 547A. It went really easy, except for one miswired capacitor, and one resistor lead that I forgot to trim. It’s funny how fast a 35W4 rectifier tube can go from good to junk when you do that, and just how bright a #47 bulb can get before it blows 😁.

I had absolutely no sound on the first attempt, and panicked. Being my first radio attempt, I had no clue where to start troubleshooting. Or so I thought. When I calmed down, I remembered all I had to do was feed a signal to the input side with the power disconnected, and I should get something out. So used my Eico 377 generator set to 400 hz and sure enough, I had sound from the speaker. Then I traced out the schematic, found the miswired cap, corrected it, and it came to life!

This morning I set up my Eico 315, and 324 signal generators, and my Tek CDC250 frequency counter, let them warm up, and connected each generator to its own channel of the counter, and let them sit for a half hour. When I started the alignment, the 315 wouldn’t hold a steady frequency, so I need to figure that one out, but the 324 stayed rock solid. Then, when the tenths digit would change on the counter, I could hear it through the radio. I’m betting that has to do with BNC to alligator clips in the counter, and the old microphone connector to clips setup I was using. So it looks like all the old Eicos are getting BNC connectors now!

So, if your still reading my jumbled mess, just know that you’re probably smarter than I am, so If can manage to take a dead, old, AA5, and bring it back to life, so can you! Just don’t panic if something goes wrong, go back and give Mr. C’s videos a rewatch, because he’s probably covered your problem in one of the videos, and keep using your brains. You’ll figure it out eventually. Mr. C has given us all a pretty good set of mental tools to work with, to diagnose these little problems. And Mr. C, if you happen to see this, Thanks for all you do. I’ve always wanted to do this, but have always thought radios were a bit of dark magic, and was above me. Thanks for shining a light on it, and showing me I was wrong!