Hello friends, attached are some photos of the radio I have. It used to work decently. Several years back, it started to have a problem. They only way I can explain it is like a "an electrical storm" in the power tube. I of course have not plugged it in since and my uncle, (87 GE for 40 years) gave me a replacement checked power tube and checked all the other tubes. Between the two uncles, I have come to learn the following: The capacitors dry out and lose function. He cautioned me they have positive and negative poles so replacement must be mindful of that. Not sure why but he said "only use resin core solder when you rewire it" but he did.
That is all I have to work from. I have decent mechanical skills, I was a professional mechanic. But my expertise is really in medical imaging, analog and digital systems.
What I think I need to have a shot at success?
photo of radio with the resistors circled to be replaced, source and part numbers. I can provide the stock photos once I have it on my bench
Same for capacitors
Same for the caps? (sorry I don't know what those are just heard they need to go)
Any other tips, watch outs and whatever you do "don'ts".
My uncle said he was astounded to see the wheel tuning cord and system working perfectly with the original cord. Since I like the short wave and that requires tuning if you members think that has to go while it's apart I'll need to know that too. So begins the Odyssey, I was told it's best to keep it all in one thread so this is it!
I look forward to all your replies and thank you so much in advance. Here's my radio:
(This post was last modified: 08-18-2020, 05:47 PM by escapefromny.)
Thanks a lot, so eight right? I'm going to need a lot of study to find what you circled in the radio, I have no experience with schematics. I asked my field engineer if I could get some help, we are both retired. This guy used to tear into x-ray generators and more and he said " I don't think I'd be any good on that project". Great! That made me pause and think of how nice it looks as an antique piece! I'm not giving up that easy though. I'm going to go look at that link.
Radio in general teaches patience and persistence, do not hesitate for help here or a local radio club, many willing to help, it may take a winter. Nice radio, good luck, be careful, it can be fun. Paul
Paul, I'm already taking pause. My cousin said last night, "that should be a straight forward repair". Sure Bob, that 1001 Radio Shack board I had as a kid was perfect preparation, I got this! But I don't at all in reality. My plan was to first replace the capacitors as directed by the two uncles, if I lived near the 96 year old he could guide me. It would also have been a cool legacy, his brother bought the radio. He'll have to support me on the phone, not particularly helpful for a guy who has no experience with schematics.
If someone could post where you get your parts and the capacitor order numbers for this radio that would be greatly appreciated. My cousin looked at the schematics last night and said it appears there are polarized and non polarized capacitors in this radio, does that sound right? Thanks to everyone for their immediate patience and encouragement.
(This post was last modified: 08-19-2020, 05:18 AM by escapefromny.)
Page 4 of NA link David provided contains the parts values.
For the capacitors it is good to not think much and assume 630V voltage rating.
The sources: many, including AES (antique electronic supply), Mouser, and I forgot who - someone here is a re-seller too.
People who do not drink, do not smoke, do not eat red meat will one day feel really stupid lying there and dying from nothing.
The capacitors in your parts list are called condensers and there are several types. The ones you want to replace right away are the tubular, which are paper caps, and electrolytic, which are polarized and used in the power supply. You can purchase poly film caps for the tubular and aluminum electrolytic caps for the electrolytics. The capacitance you should buy will probably be different from what is listed. The standard values today are slightly different from the old ones. So when you want a. 05mfd you will want to order a .047mfd, replace a .003mfd with a .0033. As Mike said, get the 630 volt poly caps and at least the listed voltage for the electrolytics. Your radio has at least one bakelite block, called line condenser in the parts list, which contains 2 capacitors. Replace these with 2 Y2 safety caps. There are several techniques for replacing them which you can read about elsewhere in the Phorum. The mica condensers rarely go bad. Compensating caps are adjustable and are now called trimmers which are used for alignment of the radio. There are 2 tuning condensers which are the plates that move when the tuning knob is turned. They will probably have to be cleaned with an electronic spray cleaner. After cleaning lubricate the bearings. In the schematic, the capacitors that are adjustable have arrow heads. When you order your parts keep in mind to check quantity breaks. If you want 5 or 6 of one value you'll often spend the same money for a quantity of 10.
For resistors learn the color code. You probably have dog bone resistors in your set. The color code is the same as modern resistors but you read it differently, BED: body, end, dot. I use 10 percent as a go/nogo, most use 20 percent.
You have plenty to absorb, so good luck and ask questions when you're stuck. Hope you have a soldering iron.
Rod
(This post was last modified: 08-19-2020, 08:40 AM by RodB.)
Four months ago, I had never laid eyes on a schematic or held a soldering iron. With lots of reading/YouTubing, trial and error, and much help from patient Phorum members, I've now replaced all the capacitors in my Philco (similar to yours) and can find my way around its circuit with some degree of confidence.
Generally, I've found that the info geared toward "beginners" tends to assume a baseline level of knowledge that I completely lacked when starting out (and still lack, actually). Don't let that discourage you. Enjoy the process of discovery, go ahead and ask the "dumb" questions, and take it slow. Every time you figure something out, two new mysteries emerge! Little by little, things start to click together.
For the capacitors and resistors, I've ordered from justradios.com and have been happy with the service. I would advise buying a kit. If you tell them the radio you're working on they'll point you to the right kit, probably $99 (shipping is free). That may seem like a lot to spend all at once but it's worth it.
Agree on the kits. You'll save on postage over ordering just what you need. Besides, if you do one radio, pretty soon you'll have another and then another to do!
