Audio Systems: 1968 Volvo 122 coupe with no volume, defective capacitor, amplifier section


Question
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Followup To
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My radio produces  good quality sound but the volume is very poor.
   
Is this an amplifier that has gone wrong?  

The exterior antenna  is attached to the radio (noise is produced when I wiggle it).  Could a fault in the antenna explain the lack of volume?

What about the loudspeakers?

If there isn't a 'simple answer' to this problem, could you recommend a book I might read to sort this out?

Thanks very much for offering your expertise.

Jim Taylor



Answer -
Hello Jim,
Please give me some more details about the problem. Does the sound have a buzz or static in it? Or is the volume very low? Give me the complete model number of the radio.

TOM,
T&D ELECTRONICS
tdeser@zoominternet.net

Tom,

The band of the radio is BENDIX  at the buttom of a "100% Certifation test' attached to the body of the radio there is a number :
2092214-0019
Answer -
Jim,
The problem may be a defective capacitor or a transistor in the amplifier section. A good way to test the antenna is to switch to AM, if AM stations come in good then the antenna may be OK. As for the speakers, they could be warped and the cones are sticking and this would not give you good volume, however in most cases when this happens any sound produced would be slightly distorted. By my experience based on the age of this radio, I would replace the electrolytic capacitors in the audio output section.

TOM,
T&D ELECTRONICS
tdeser@zoominternet.net

Tom,
Thanks very much for you guidance.

Where would I locate capacitors for this age of the radio?

Answer
Jim,
Any electrolytic caps will work as long as they are of same values. As for the numbers that you gave me none of them will cross to a model number. If possible give me all the numbers that you see on the outside of the case of the radio. also open the covers and look for stickers or any other numbers that you find. I will need a model number to locate the service data in my files.

TOM,
T&D ELECTRONICS
tdeser@zoominternet.net