Hello!
I pulled this little guy out of the FM module of a Fleetwood tube radio from the early '60s. It was causing intermittent problems due to a broken leg. When I tried testing it, it's other leg fell off too, but there was enough metal to try. I think it's a 'dog bone' resistor, but I've also seen photos of antique ceramic caps that look similar. I tested for resistance and capacitance and got nothing (open resistance). There are about 5 of these type of parts mixed in with normal looking carbon resistors and ceramic disc caps, so I'm not sure why they're needed (and only in the FM circuit). I pulled a couple similar parts out, but they also failed to test. Could they perhaps be tiny wire wound resistors that blew with a surge? Or maybe out of my meters range? I tried for hours to find a schematic, but could not.
Anyway, the main part in question is grey with a green dot on the left end, with 82 printed on the body. Grey would match up with the 8, and green could be the multiplier? So maybe a 8.2 Mega ohm resistor?
Any help or insight would be greatly appreciated
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I pulled this little guy out of the FM module of a Fleetwood tube radio from the early '60s. It was causing intermittent problems due to a broken leg. When I tried testing it, it's other leg fell off too, but there was enough metal to try. I think it's a 'dog bone' resistor, but I've also seen photos of antique ceramic caps that look similar. I tested for resistance and capacitance and got nothing (open resistance). There are about 5 of these type of parts mixed in with normal looking carbon resistors and ceramic disc caps, so I'm not sure why they're needed (and only in the FM circuit). I pulled a couple similar parts out, but they also failed to test. Could they perhaps be tiny wire wound resistors that blew with a surge? Or maybe out of my meters range? I tried for hours to find a schematic, but could not.
Anyway, the main part in question is grey with a green dot on the left end, with 82 printed on the body. Grey would match up with the 8, and green could be the multiplier? So maybe a 8.2 Mega ohm resistor?
Any help or insight would be greatly appreciated
Has {nearly} no business in an FM tuner.
I would bet a penny on a capacitor, possibly 8pFd, which is about impossible to read with a bench meter. But the coil theory is worth a penny also.
Fleetwood radios did not have model numbers?
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I'm thinking 8.2 pF ceramic capacitor or 8.2 nH inductor. Probably capacitor.
Tom
Tom
8 Megs does seem high! I thought it might be an inductor, but that would have given a reading. There are also a few bare copper coils and one pancake pcb coil, which makes me think the inductors are taken care of. Fleetwood (from what I could find) was a small Canadian company that seems a bit similar to Grundig. This is from a giant wooden console and all is says is Fleetwood Custom High Fidelity Stereo Receiver.
I'll throw a cap in tomorrow and see.
Thank you!
+1 on an 8.2pF capacitor, of course impossible to read with a hobbyist meter.
Such low values are often used in compensation, neutralization, and of course it being an FM radio, frequencies involved are around 100mHz, so 8.2pF is not an irrelevant or outlandish value by any means.
Just get and solder an 8.2pF ceramic there, radio should return to normal.
For those thinking "8.2pF is a VERY low value, what possible effect it might have?", sometimes even smaller "pinch/gimmick" capacitors were used , 2 short pieces of wire (less than 1/2") twisted together, effective value being wire to wire capacitance, a few pF 😱
http://sm0vpo.altervista.org/begin/gimmik-0.htm
Such low values are often used in compensation, neutralization, and of course it being an FM radio, frequencies involved are around 100mHz, so 8.2pF is not an irrelevant or outlandish value by any means.
Just get and solder an 8.2pF ceramic there, radio should return to normal.
For those thinking "8.2pF is a VERY low value, what possible effect it might have?", sometimes even smaller "pinch/gimmick" capacitors were used , 2 short pieces of wire (less than 1/2") twisted together, effective value being wire to wire capacitance, a few pF 😱
http://sm0vpo.altervista.org/begin/gimmik-0.htm
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People who think 8pf couldn't affect anything are thinking only in audio land.
Those little tubular capacitors vary with temperature and often have a companion with a different temperature variation to keep the set on the tuned station as it warms up.
It is worth trying to solder the wires back onto the two ribs (not the body).
The green will be the temperature code.
The components are accurately placed due to capacitance between them.
It is worth trying to solder the wires back onto the two ribs (not the body).
The green will be the temperature code.
The components are accurately placed due to capacitance between them.
Thanks everyone! I won't get to it until tomorrow or Tuesday, but will update you then.
Could this capacitor being out of whack be responsible for the dail and stations not lining up?
Could this capacitor being out of whack be responsible for the dail and stations not lining up?
I would suspect a much more mundane problem: those old tuners typically used a piece of waxed string o similar to couple tuning knob - tuning capacitor - dial needle together, VERY easy to stretch and slip so "showing" the wrong frequencies, nothing indicating at all that there is a real Electronic misalignment problem.
Old schematics, such as Sams Photofacts (search for your model there) often included "restringing" instructions, if not search old radio Fan sites , even YT might have a couple videos.
No big deal.
EDIT: here´s EXCELLENT Uncle Doug advice,
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Use polyester thread, from a sewing supply or kite string.
Less prone to stretching than cotton.
Less prone to stretching than cotton.
There ARE places online to purchase real (Google - "dial cord") instead of putzing around with inferior subsitutes and plain string.
It comes in various sizes, and usually has a reinforcing core to prevent stretching and changing indicator alignment.
But since that radio has been compromised already, it'll now require proper repairs and alignment procedures.
Otherwise shelf-it.
It comes in various sizes, and usually has a reinforcing core to prevent stretching and changing indicator alignment.
But since that radio has been compromised already, it'll now require proper repairs and alignment procedures.
Otherwise shelf-it.
Dial cord last seen in 80s here.
Polyester thread, braided, about 0.5 to 1.5 mm diameter, is a good substitute.
eBay prices are $5 to $195 for dial cords, the high price is for a reel.
Polyester thread, braided, about 0.5 to 1.5 mm diameter, is a good substitute.
eBay prices are $5 to $195 for dial cords, the high price is for a reel.
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