A quick walk through the circuit with a VOM showed that the reason for the fever were a few bad resistors.
Though I was careful to check the resistors before I ordered parts for this radio, now nearly every one of them were reading very high and well out of tolerance. Two, which showed good when initially tested, were now completely dead! (infinite resistance)
Another quick order to AES and the problem was solved. A quick replacement of all the resistors and then back on to the dim bulb tester for safety's sake, then back to full power. This time the fever was cured.
I then ran the radio for a full hour to ensure that the problem was indeed solved.
There is still a slight problem with the dial lamps. One glows about half as bright as the other and often fades out. Both lamps flicker with modulation though, a problem that definitely deserves attention. It is also in desperate need of re-alignment and the cabinet needs to be refinished but at least it's now safe to listen to it's golden tone again.
7 comments:
I have one of these too; it was my grandfathers. The cabinet looks in pretty good condition. The dial doesnt work, but it has all the tubes etc.
Does yours get anything besides AM broadcast?
to be honest, I've never really tried any of the other bands. :D
I'll give it a go and let ya know :)
Ive taken the guts out and ready to clean.
How do you recap?
Well, for starters, I don't recommend that a beginner gut their radio, but since you have begin with a good copy of the schematic diagram, wiring diagram and parts list.
You will need to purchase the capacitors in the nearest available value to those listed on the parts list. Do not deviate more than 5% to 10% of the listed value.
DO NOT BUY NOS CAPACITORS ESPECIALLY ELECTROLYTICS
Electrolytic capacitors dry up over time and can explode with a force equal to 1/4 stick of dynamite.
For the large metal electrolytic cans mounted to the chassis of your radio, simply leave them in place and DO NOT solder any wires to them AND DO NOT USE THE SOLDERING LUGS. Just solder in a modern electrolytic and leave the old cans as decoration.
For all the wax caps, just replace them with modern capacitors.
I also recommend joining a good forum such as Antique Radio Forums or Tube Radio Forums. Both have experienced technicans who can give you step by step help as you learn. :)
God Bless and Good Luck :)
Enjoyed your blog and love your beautiful radios!
Great blog. Ran across it while working on my RCA 86K7. How did you get the dial needles off without damaging them or the shaft?
Nelson 3140
My apologies for not replying before now. Certain changes somewhat forced me out of the hobby and I failed to check the blog.
The hands on my radio just popped right off without a problem. Just keep a smooth steady outward pressure and be careful to pull STRAIGHT off so nothing strips or bends.
Would love to see pictures of your project. :)
Post a Comment