radio humming

[Cpt.Fred]

just read the thread about that beautiful barnfound 40 dodge from 2003...

i noticed they mentioned the radio would come on and hum and that "the speaker cones need replacement".

when i got my P10 (which was in a slightly worse but otherwise very similar condition) i had the same thing, the radio hums, but there is no speaker on the car any more, so i turned it off instantly and took the fuse out to prevent any damage.

i don't know what type of speaker to use.

do you think the radio coud be reanimated on a short budget

or should i best leave my hands off of it?

would sure be great to listen to old hank or the carters in the car...

[Cpt.Fred]

just did a quick search and found i could use old speakers from radios or tv sets from the 50s...

maybe i'll have to part out some fleemarket find.

[BobT-47P15]

Fred, they say you can actually use modern speakers instead of looking

for an old electromagnetic one. There are some old threads about

radios and speakers.

[Cpt.Fred]

that's good news,

but i still think there must be some damage inside

the radio due to the long storage period.

it can't be the cones alone (especially when it isn't existing )

do you think it's save to try connecting a random speaker to the radio and turn it on?

[Furylee2]

I’ve had a couple of Model 800 radio’s fixed for my 41 coupe. My radio guy say’s if it’s humming that’s a good sign, the vibrator still works. I would locate a speaker and give it a try. In the worse case, you may only need a tube or two, but it might just work. He has a source for new vibrators, but they are solid state.

[Cpt.Fred]

ok, so next thing would be locating the wires / the connector and try to put a speaker in there...

didn't the old speakers have 3 connectors, not only 2 like modern ones?

[P-12 Tommy]

Fred, The radio has 3 connections. Power, ground and VC (voice coil) which is speaker. You'll have to ground the speaker. If I'm wrong, someone will chime in.

Tom

[Cpt.Fred]

thanks!

[TodFitch]

I am not an old tube radio geek by any means but it is my understanding that one of the principal problems is aged capacitors, not the speakers.

It is also my understanding that the fixed magnetic field in the speaker on those old units was provided by a coil as the magnetic materials available back then was not as good as available now. (Current speaker designs have a strong permanent magnet made of materials invented in the last couple of decades.) Thus the extra connections to the speaker, they are to provide power to the coil that provides the fixed magnetic field. However I understand that this "extra" coil was then put into use as a noise filter/choke that was an integral part of the radio's power supply.

Anyway, it would probably be a good idea to take the radio to a person who has some experience and understanding about the older ways that radio receivers were put together. It might be a local ham radio operator in your neighborhood or it might be a professional antique radio repair person.

[BobT-47P15]

Tod is right about those things.....

The guy who is going to work on my old radios says capacitors go bad

with age. They do the same thing in guitar amplifiers. Then check for

any bad tubes. Then probably replace the vibrator. There are solid

state vibrators for 6 or 12 volt.........shouldn't be a big deal if not an

original vibrator.......who sees it inside the radio?

[TJM70's_48]

I successfully rebuilt my radio. It is not hard, although a car radio isn't probably the best place to try and learn. Antique radios have been a hobby of mine for many years.

The vibrator - which creates AC (around 250v, if I recall) from DC will hum in a working radio.

It's best to NOT try to play a radio if it hasn't been repaired. The capacitors are almost certain to be shorted. If there's a serious enough short you could toast a difficult to replace part.

My radio was missing the speaker. I started to track down an original one, but, was talked out of it by more experienced radio men than myself. The logic was that a modern permanent magnet uses a little less current - thus a little easier on the electrical system. The catch is that our cars seem to have a 6" speaker and I think it's not an available size anymore. I ended up using a 7" and making a sort of a bracket to mount it.

So far as connecting a 2 wire speaker to the 3 wire setup, I just touched wires to the speaker posts until I found the two that gave me sound on the workbench (used a 6V battery charger as power supply while doing the repair...positive to the radio chassis and negative to the power cord of the radio). Then, I cut off and taped the field coil wire.

It's been more than a year since I did my radio, so my memory is a bit cloudy...but if anyone has questions, I'd do my best to help you out.

I would also suggest adding an mp3 input jack while you're in there...I hide an mp3 player in the glove box and get to enjoy the music I want while driving...there's not much on the AM bands anymore!

[insaneradio]

If you have the model 802 you will have three wires attached to the speaker. One is for the field coil and two for the voice coil of the speaker. If you wish you can use a new permamanent magnet speaker by disconnecting the brown wire from the speaker plug and cap. This was for the now non used field coil. Attach the remaining two wires to your speaker. Keep in mind the one wire is simply a braided shielding which attaches to ground. I suggest you not use the braided wire but rather run another wire from the speaker to the case of the radio.

As others have stated their is a good chance your vibrator is working if it hums. I built a tester for testing these four pin vibrators and will test for free if you wish. Often times NOS vibrators will not work even if in original box. The contacts get oxidized over time. FWIW I have had good success repairing these old vibrators. I like the original hum of the radio.

The capacitors in your set if not restored will be of wax/foild and paper. Over time these degrade as well just sitting on the bench. The only way to have a reliable good playing set is to replace these capacitors along with what are called filter capicitors.

Any further questions please feel free to ask,

Dave

ok, so next thing would be locating the wires / the connector and try to put a speaker in there...

didn't the old speakers have 3 connectors, not only 2 like modern ones?

Edited July 22, 2010 by insaneradio

[Cpt.Fred]

thanks to all of you!

these are once again great tips and info.

i have an antique radio from the fleamarket,

i will open it and check everything out to get into the material.

then i will try to get my radio out of the car, by the way it's called "firestone air chief" on the casing.

i'll post a picture in a few minutes, have to dig...

best, fred:)

[Cpt.Fred]

ok, i haven't found one of the casing,

but these can help as well i guess.

from when i got the car:

1. radio controls with all buttons missing:(

2. controls from the back:

3. cables going into the radio:

4. inside the casing:

is that a model 802?

[james curl]

Aftermarket, I believe all of the factory models were all in one case and mounted behind the dash not on the firewall. My car has an aftermarket Motorola which mounts the main body on the firewall just above the steering column with cable controls to the head in the dash.

[BobT-47P15]

Fred, you do indeed have an aftermarket two part radio. They worked

fine in their day. Take up space in a different manner than an 802.

Here's a picture borrowed from ebay of an 802.

The speaker is separate, of course, located behind the

grille work in the middle of the dash. I believe it was a 7 inch

diameter item.

All the different makes of Chrysler cars used that same radio.

[insaneradio]

ok, i haven't found one of the casing,

but these can help as well i guess.

from when i got the car:

is that a model 802?

Fre,

Yours in not an 802. I am unsure what model vehicle you have?? It is possible the model 802 was not available for the year of your vehicle?? At any rate it is an interesting set. I have always liked the sets with seperate controls. I am rather certain it could be restored. Finding the buttons may be a little dificult however. IF you were closer I would take it in to work on. Radios have been my passion for a lot of years.

Dave

[Furylee2]

I am not an old tube radio geek by any means but it is my understanding that one of the principal problems is aged capacitors, not the speakers.

...

Anyway, it would probably be a good idea to take the radio to a person who has some experience and understanding about the older ways that radio receivers were put together. It might be a local ham radio operator in your neighborhood or it might be a professional antique radio repair person.

I think Todd is right about the capacitors. I just had the radio for my 37 repaired, and got back a zip lock bag full of the old capacitors.

The correct radio for the 40/41 is a model 800. I have some paperwork I bought on the Bay some time back, that shows how to cut the radio dash grill to install the 802.

At least you can stop searching for a speaker. I can see it in the radio.

[Young Ed]

The p15 that this pile of parts came from must have had one of those aftermarket radios. You can see the 2 knobs at the front and somewhere in the pile is one of the control cables.

[BobT-47P15]

The ebay seller says this is a 1940 Mopar radio............

Case looks similar to newer ones.

[Furylee2]

The ebay seller says this is a 1940 Mopar radio............

Case looks similar to newer ones.

That is the correct radio for the 40/41. I bought several over the years, and I put one in my buddies 40 Coupe.

The difference is between the dial and the buttons. On the dash grill, there is a piece that is part of the grill that the radio fits behind. I won an auction some time back with the little labels that go behind the buttons, with the station call letters. It must have been for a dealer installed radio, because it showed how to cut the opening bigger to install the 802 in the 41 dash.

There was an auction for one of those Firestone car radios that ended. Not the same, but similar with the cables.

http://cgi.ebay.com/ebaymotors/Vintage-FIRESTONE-Air-Chief-car-radio-Ford-Chevy-Dodge-_W0QQcmdZViewItemQQhashZitem3caf148d0bQQitemZ260635397387QQptZMotorsQ5fCarQ5fTruckQ5fPartsQ5fAccessories

Sorry, but for some reason I can attach pictures or create the correct link for the auction. Might be time for a reboot.

[Cpt.Fred]

you guys are great, thanks!

furylee: as for the speaker, do you mean that cone in the bottom of my last picture?

never thought of that since there was an empty space in the dash and

it seems rather strange to me to put the speaker right above the steering column under the dash, but then again, what do i know?

a working 802 will be very expensive...?

i guess i'll just take mine out and have a closer look at it.

can't be that hard...

young ed: that pile of parts isn't for sale, is it? i know a certain person badly wanting some of that stuff...

since i have a lot of unwanted work ahead of me since sunday's ride back home,

i'll have to move this part of the project to the winter months, anyway.

Edited July 27, 2010 by Cpt.Fred

[Young Ed]

Fred some of it is some of it isn't. Pm me a wish list

[Furylee2]

you guys are great, thanks!

furylee: as for the speaker, do you mean that cone in the bottom of my last picture?

never thought of that since there was an empty space in the dash and

it seems rather strange to me to put the speaker right above the steering column under the dash, but then again, what do i know?

a working 802 will be very expensive...?

i guess i'll just take mine out and have a closer look at it.

can't be that hard...

Fred, yes, that is the speaker at the bottom of your last picture. I had a similar aftermarket radio in my 41 coupe when I bought it (didn't work). It mounted on the firewall above the steering column, just like the one in my 37. And yes, the speaker is inside of the radio in both of these.

I’ve bought several model 800 radios on eBay, some for as little as $10. But they are heavy, and the shipping was between $15 to $19. I’ve had 2 or 3 of them repaired, which run around $80 for new capacitors and vibrator. I painted a couple of them up and sold them two friends who wanted a radio in the dash, but didn’t care if it worked or not.