Need help with determining why my reception is still weak to non existant. I sent my radio out to have it gone thru (alignment, clean-up, etc.) when I got it back I called the man and he said the radio worked great he just had to tweak a bias voltage on it and align the pointer. I installed it my my car and I got garbeled voices and the only way you could hear anything was with the volume turned nearly to full volume. AM didn't work good either so I was told to check the integrity of my antenna (Made sense) I removed the antenna cleaned all the ground connections for the ground strap to the frame, checked the coax with an ohmeter to make sure it wasn't shorted or open it was OK. I reinstalled everything and the sound was maybe a little better but far from correct. My question is could the speaker be the problem? I ohmned out the speaker lead and it measures 11.2 ohms. Someone tolde me it should be 10 ohms. Any suggestions on what to do next is sure appreciated!
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Re: C2 radio speaker
Forgot to mention I also installed a new reflective ground plate. -
Re: C2 radio speaker
Sounds like you've covered all the bases except the speaker. The cone may be shot/loose. There are places that recone speakers. I've seen one in Charlotte NC. Don't remember the name but you may be able to find someone on the internet.Comment
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Re: C2 radio speaker
Steve,
LIC sells what I am told is an electronically correct speaker for about $30. It includes the transformer and a decent sized magnet. Charles Seigfried (sp?) who is overhauling my radio suggested them as a source.
DaveComment
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Re: C2 radio speaker
Jim,
Your repair man adjusted the bias voltage on the collector of the output transistor. It should be adjusted for 1.5V. This is the big transistor on the back of the radio.
What has happened here is the resistor that is used to adjust the bias is a wire wound resistor and it corrodes. When it was shipped back it lost it adjustment or the corrosion took over.
It's on the bottom of the radio and there is a small hole to put the screwdriver thru.
If you have a voltmeter or can get one, just attach the positive lead on the fins of the output transistor and the black lead to ground. Then adjust for 1.5V on the DC scale. Your radio will probably start working great.
You don't need a new speaker I don't think but if makes you feel better go ahead and spend the $40.00 to $50.00.
Regards,
JRComment
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Re: C2 radio speaker
I had my '63 AM/FM radio done last fall by Retro Radio in PA. He told me he needed a speaker to tune the radio to the speaker. So I drop shipped a new speaker from LIC. It was so far out of spec, RR returned it to LIC saying it would have caused a wiring fire within 30 mins. So I sent my beat-up (no wiring connections and little cone left) speaker core, and he sent it over to The Speaker Shop in OH run by a guy named Nick Dorazio - nijaq@aol.com. Here's Nick's first email:
"Good evening Pete, the site does not explain the process but, the speaker's voice coil and spider and of course cone are replaced with original parts!! 30 years of collecting and purchasing other companies inventory has allowed us to keep many older speakers sounding as new. The turn around varies from 5-14 days (working). We will email you once unit arrives at our door and will keep you informed with costs and shipping tracking number(s)."
Six days later, my speaker was back at RR, the speaker price was $55.29, and that beat-up speaker looked and sounded BRAND NEW. New voice coil, new cone/cover, all new wiring (he was able to re-use the choke (it's not a transformer).
PeteComment
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Re: C2 radio speaker
Gordon,
That is interesting. I spoke to Charles Siegfried, who is (I believe) one of the best vintage radio repair people in the country, and his suggestion as a source for the speaker was LIC. When I sent him my radio I told him I had no speaker and asked him if he could supply a electronically correct speaker. He said to order it from LIC and it would work fine. Since he provides a 3 year warrenty, he has an interest in the quality of the speaker that is used.
I plan to call him today to ask him about the status of my radio (it should be close to being done) and I will ask him again and let everyone know what he says.
DaveComment
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Re: C2 radio speaker
Jim,
While I don't have a C2 I have worked on many such systems. The difference from 10-11 ohms on speaker impedance is imperceptable and mostly affects system efficiency for power transfer. I doubt you could tell the difference in 8 ohms either. Most likely your speaker has a bad cone, or dirt in the voice coil. The advice to recone is very good. I have done several and they come back good as new. I use a place in Colorado Springs and will email you the info if you desire. Bias on the transistor could be a problem but unless that wirewoundpot is really bad I doubt it changed.
Just plug any 8 ohm speaker in place of the installed speaker. If the sound cleans up then the speaker is your problem. If not, the problem is elsewhere. These old cones get sun damaged, and get torn, etc, all of which deteriorates the sound. If you need more advice, email me directly.Comment
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Re: C2 radio speaker
I hooked up a known good speaker form my home stereo and the radio works fine. I have never seen this before - I ohmed out the speaker and the cone material is not damaged but apparently the voice coil is frozen. I am going to send the speaker out for rebuild. Thanks everyone!Comment
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Re: C2 radio speaker
You know, that's what I had heard too. And I'm a regular at LIC anyway. So it was a no-brainer. But the guy at Retro Radio was really disgusted with what he received. Here's a portion of the email I received from him:
"There is no way that I can adjust the bias of the output transistor with that speaker and choke combination. It is WAY out of spec. Aside from that, the assembly is sloppy with the choke loosely pop-riveted on the speaker. Sure to cause rattling and buzzing. I will send it back to get you a refund."
I was surprised. LIC had no trouble or comment taking it back. But I'm very happy with the route I took as well - another original piece saved.
PeteComment
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