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Expert
Posts: 2202
 
Location: Muskego, WI | I recently corrected the reversed polarity in my 1958 Belvedere so I thought I'd dig into the radio. I have the 854 model which is a transistor model, after removal I found that the fuse was burned out. Replaced the fuse and re-installed the radio and it worked... for a while any way. The power stays on to the radio but no sound comes through. I turn the volume knob and the static volume doesn't increase, just stays faint. The power connection, ground and speaker connections are all solid. When I turn the radio on and off, I can hear the speaker "pop" on and off, but often there is no sound other than the faint static regardless of how high the volume knob is turned up. Other times the radio comes in loud and clear. Any ideas? |
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Expert
Posts: 3408
Location: Chestertown, NY ( near Lake George) | Yep, something wrong internally with maybe speaker amp unit, send it out and maybe upgrade to AM-FM. |
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Expert
Posts: 2264
Location: McComb, Mississippi | Try adjusting the screw on the side of the radio by the antenna... Before I took all the guts out of my radio, my radio did the same thing and I turned the adjusting screw and the static became much louder and I began to piuck up stations..Worth a try... |
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Expert 5K+
Posts: 6520
 
Location: Newark, Texas (Fort Worth) | My friend Jerry says the volume control go out on these alot. There is an upgrade for these too. Lets see if he is here and answers...
The mod also calls for a
different volume control, 1 megohm instead of the 3 megohm
part factory installed. My radio also uses a 1 meg ohm,
(part numer 33-5580-21), but the mod reference is to the
part number 33-5580-17. The drive signal for the search
relay uses the rectified audio signal to bias the relay
switch and apparently this change provides a signal boost.
Edited by mstrug 2012-04-23 9:20 PM
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Regular
Posts: 60
| The 1958 Mopar model 854 is NOT a transistor radio. It is a "Hybrid" auto radio that has vacuum tubes inside with Transistorized Audio Outputs. Chrysler and its divisions did not have all-transistor radios available in its cars until 1964. Although, Chrysler did come out with a test market All-Transistor car radio for only one year, which was an option on the 1956 line of Chrysler and Imperial cars (Mopar 914HR). This was the World's First All-Transistor Car Radio to be developed and produced for cars. Chrysler had made this News development announcement in April 1955. But, this all-transistor car radio was very expensive and was also a poor seller in 1956. So, Chrysler had decided to stop making them as an option, when its 1957 cars came out and instead starting making "Hybrid" Transistorized auto radios for its new line of cars (1957-1963).
Edited by electricalengineer 2012-04-29 10:16 PM
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Regular
Posts: 60
| This Radio will not work with "Reverse" polarity. In fact, you can do do serious damage to the internal electronic components that are inside this "Hybrid" car radio unit.
I do not have this particular schematic for your Mopar model 854.
Do you know if your radio that you have, is a positive or negative ground chassis design ? |
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Regular
Posts: 60
| HI
I found some info. on your 1958 Plymouth Mopar model 854 car radio. This radio was a "Hybrid" car radio that was made by Motorola and it contained (4) vacuum tubes inside unit and also had (1) Audio Output Power Transistor that was attached to the outside of Radio's chassis, which acted as a heat sink for this Power Transistor.
Thanks Rick
 (Chrysler Plymouth Mopar Model 854 Hybrid car radio=1958.jpg)
Attachments
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 Chrysler Plymouth Mopar Model 854 Hybrid car radio=1958.jpg (27KB - 301 downloads)
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Expert
Posts: 2202
Location: Muskego, WI | That would be my radio. I corrected my car to 12V negative ground, it had been running 12V positive ground. The radio will work when cold and then stop after about 8 minutes at mid volume. Guessing that once something warms up too much it cuts out. Oh well, I can live with it for a while. |
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Extreme Veteran
Posts: 337
Location: UK | The radio in my dodge works fine on switch on. You hear a pop as it's switched on (that will be the transistor output stage) but after a while starts to sound overdriven and distorted when it gets warm. If it gets too hot it cuts out and back in again.
It sounds to be you have not done any lasting damage to your radio but the components inside are so old they are out of tolerance (capacitors especially dry out) and will need to be replaced. You may be lucky and it will only need a couple of adjustments like setting the voltage on the tube heaters for the receiver circuit. Tubes don't last forever either and it may be their time is up too.
I've not had mine apart yet to see. I work in electronics (I get by) but never worked on anything with tubes myself so it will be a totally new experience. |
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Expert
Posts: 1737
Location: Hay Lakes, Alberta, Canada | You will probably want to take your radio out, and have it "tuned up". All old radios, regardless whether they are tube, transistor, or a hybrid, have components that get dirty, and age with time. You should have the controls cleaned, the tubes checked (replaced if poor), electrolytic capacitors replaced (as mentioned, they dry out), all resistors tested (replaced if out of tolerance) and all the dust and crap cleaned out of the insides. Also, you may want to check your speakers and see what kind of shape the cones are in. They will need to be re-coned if the paper cone is shriveled up or dry rotted. I have done may of these radios- they are not hard to work on.  |
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Elite Veteran
Posts: 1110
Location: Tulare Ca | How Difficult Would It Be To Convert A Radio Delete Car To Have A Radio?
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Expert
Posts: 3577
Location: Blythewood, SC | Myke - 2012-06-25 3:12 AM
How Difficult Would It Be To Convert A Radio Delete Car To Have A Radio?
Get a radio off e-bay, install an antenna, install a speaker, hook the radio up to the speaker, the antenna and the positive lead ( which I think is off the back of the ignition switch or the lead for the clock power, I can't remember off the top of my head) and that's it. |
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Elite Veteran
Posts: 1110
Location: Tulare Ca | Simple Enough, Thanks! |
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1958 Plymouth Belvedere radio
