opened the casket on my radio

[maurice wade]

Last night I removed the radio from the dash, (p-15). I opened the side covers, and to my surprise, the inside of the radio was almost spotless. I cheched to see if all the tubes were tight, and they were. That is as far as I could go. My radio is humming, humming really loud. I can still hear music. I did notice in between the speaker wires and the radio was a small round plastic device. It is dark brown in color, and the wires run through the device. the center of the device is metalic, about 1/16 in diameter. It looks as though it was attached to something. What I don't know?. What is this plastic junction box for? 'Does it come apart? if not one will have to pull the speaker or un solder the wires from the speaker. Could a defective speaker be the cause of the humming? Will any speaker work as a test replacement? Any help is much appreciated. Maurice

[mackster]

Any speaker will do for the test. my first move would be to remove all speakers connected to the radio and crank it up to see if the humming is internal on the radio or on the speakers/the wiring connected to the speakers. if I dont hear anything then I would connect another speaker and wiring to test it. try to splice close to the radio if you are going to do it. I know that if the wires on the radio/speakers are cross(like if they are connected together) they will cause a humming that would get louder as the volume is turned up, but you will still be able to hear the music (may sound little mouffle)

hopefully this works for you...

[BobT-47P15]

I believe the radios in the P15s had an electromagnetic speaker.

There is a round plastic plug on the wire that goes from the radio

to the speaker. It plugs into a recepticle on the speaker.

You can see the round plug on the radio in the top picture.

I think a newer style speaker may work with these radios, but you may

need to experiment with it. I'm not much of an electronics expert.

[Oldguy48]

If the humming is originating at the loudspeaker, chances are that there are some capacitors in the radio that need replacement. The vibrator and transformer in the radio produces a high voltage alternating current that is then converted to DC, and filtered by the capacitors. The tubes require this high DC voltage to operate. If the filtering isn't sufficient, the result is humming that is audible through the loudspeaker, and these capacitors can deteriorate with age, and lose their effectiveness. The capacitors don't unplug like the tubes. They are soldered into the circuit, but most any electronics repair shop should be able to take care of it for you.

[martybose]

You can use a newer speaker with the old radios. When I cleverly put a screwdriver through the cone of my original speaker, I went down to Radio Shack and bought one of theirs, worked fine. I just screwed the connector plug from the old speaker to the frame of the new speaker and plugged it in.

Marty

[Frank Elder]

Does it matter6/12 volt ?

Does it matter6/12 volt for a" test speaker" on a 6v radio?

[oldmopar]

Here is a radio diagram it may not be your exact radio but it will be close enough. I would 1st check as oldguy48 said the capacitors the diagram will show you which ones and a give you a value just get ones close in value. You can get them at radio shack should only be a few dollars.

http://oldmopar.com/p15/P15radioa.pdf

[BobT-47P15]

I would think it matters if 6 or 12 V......as it was probably designed

for six. But, I'm no expert on that. Maybe a voltage reducer if you

have converted to 12V.

[Alexander]

If the radio humms and you can still hear faint radio in the back ground, this is a good sign. Replacing all wax paper capacitors will usually get it going again. In rare cases you will also need to replace the electrolytic capacitor(s) too. But first replace all the wax paper caps. While at it, I would strongly recommend you replace the vibrator to a solid-state one (see link).

http://www.tubesandmore.com/scripts/foxweb.dll/moreinfo@d:/dfs/elevclients/cemirror/ELEVATOR.FXP?item=P-V1015P

If you have more questions, keep posting and we will get you through it. These radios are not hard too fix.

cheers

Alex

[martybose]

I would think it matters if 6 or 12 V......as it was probably designed

for six. But, I'm no expert on that. Maybe a voltage reducer if you

have converted to 12V.

The speaker doesn't care if the car is 6V or 12V, but the radio does! My original 6V 802 radio worked fine on 6V, but will not work at all off of any 12V to 6V convertor that I can find.

I gather this is a common problem without a known fix, so I've bought another 802 and will have it converted to 12V via the internal solid state conversion process. Not period correct, but then neither is the alternator!

Marty

[Captain Neon]

If you're gonna go that route you might as well get an AM/FM/aux conversion. I had one done, but with the move from CO to MO have been unable to get it installed. Too much house painting and business travel. Both my Neon and the wife's Acclaim need oil changes and the Jeep will need an oil change soon too. Gotta get that done before Christmas as we are driving to Texas Christmas weekend to see the sobrinos.

[Captain Neon]

Sometimes I get a good idea. These are photos of my den in our house. My own design.

[Frank Elder]

Housepaint hijack:eek:

[maurice wade]

I believe the radios in the P15s had an electromagnetic speaker.

There is a round plastic plug on the wire that goes from the radio

to the speaker. It plugs into a recepticle on the speaker.

You can see the round plug on the radio in the top picture.

I think a newer style speaker may work with these radios, but you may

need to experiment with it. I'm not much of an electronics expert.

I wonder what this plug's purpose is. Doe's it come apart? Maurice

[maurice wade]

Alex, Where are these capacitors located in the radio? Maurice

[BobT-47P15]

Possibly it does. Would have to look at one of mine to see. Have one, I

think, still on the radio in the car - which is not hooked up to a speaker.

[Young Ed]

The plug is what makes the electrical and + - connections for the speaker. Not sure if it comes apart or not.

[Frank Elder]

Just went and raided my trunk BBRRRRRRRR,

I have sitting on the table next to me a 802 and speaker.

Not much left of the speaker I'm afraid, To answer your question, no the male end of the plug does not come apart.

It is of one piece construction. There are 5 holes in the back of the plug, 2 with no wires attached,3 with wires installed. All holes are numbered.

Holes 2 & 4 are empty and plugged on the "face side".

Hole 1-Brown wire plastic insulation.

Hole 3-Green wire plastic insulation.

Hole 5- Bare braided wire.

Hot for radio- Black wire plastic insulation with 14 amp inline fuse.

On the speaker body itself the female plug is also of one piece construction and is detachable by removing 1 sheet metal screw.

Bare braided wire attatched to speaker cone center.

Black wire-cloth insulation and White wire-cloth insulation both attached to the wire windings at the base of the speaker.

Thats all I got, hope it helps.

[maurice wade]

Thanks Frankie, I will not try to take the plug apart. Further inspection, it looks as though someone has installed a replacement speaker. That may be the reason the plug is not connected to the speaker now. Anywhay, from all the helpful feedback, I think it is the capacitors giving me the humming. The problem is I do not have a clue what they look like or where they are located. Maurice

[oldmopar]

Thanks Frankie, I will not try to take the plug apart. Further inspection, it looks as though someone has installed a replacement speaker. That may be the reason the plug is not connected to the speaker now. Anywhay, from all the helpful feedback, I think it is the capacitors giving me the humming. The problem is I do not have a clue what they look like or where they are located. Maurice

Click the link and it will open several pages of a radio diagram. Its in a pdf format

http://oldmopar.com/p15/P15radioa.pdf

[jimwheeldon]

On mine I had to hook up a real antenae-and make sure all flourescent lights are turned off.

[Oldguy48]

I have one out of the car, so I took a look. There is a metal cylindrical can type electrolytic capacitor right next to the power transformer (square metal box with ventilation holes in the top). That's the filter capacitor, and the one I would suspect first. You need to ensure the replacement has a voltage rating at least as high as the original, and at least close in capacitance value. I couldn't see the ratings on this one, but they are rated in MFD (microfarad) for capacitance value, and this one is probably around 200 MFD or so. Sometimes this type has more than one capacitor built into the "can". If you can't find an exact replacement, you can probably get individual ones of the appropriate value, and connect them in, and let the old one in place. I didn't open up the other side of the case to look at any of the other smaller capacitors in the circuitry, but typically they are tubular, 1/2" to 3/4" in diameter, couple inches long, with a wire lead protruding from each end. They normally have an identifying "band" marking one end to identify "polarity". That's especially important with the electrolytic type capacitors. They can "self-destruct" if connected improperly. Hope this helps you out

[Oldguy48]

Shel,

Those square shaped "cans" next to the tubes are IF (intermediate frequency), and oscillator transformers that pass the signal from stage to stage. The radio out of my

P15 had only one "can" style 4 section filter capacitor. The capacitance values on it are 5 MFD,10MFD,10MFD, and

20MFD. A word of caution about these IF transformers. Don't attempt to make any adjustments on these unless you are familiar with the alignment process and the circuitry. If it's misadjusted, it will take test equipment and know-how to bring it back to operating condition.

And thank you for providing the photos. Like the old saying goes, A picture is worth a thousand words"

[Niel Hoback]

Its been my experience that soldering in a warm kitchen leads to sleeping on a very cold couch.

[Oldguy48]

Niel makes a good point....unless the better half is at the mall on a shopping trip while you're using the kitchen table:D