AMC Rambler radio speaker

[AL1630]

I have a 1963 Rambler American with a Bendix 3TBAM radio, which I believe is all transistor. The manual for the radio and a sticker on the side warn to 'Use 20 Ohm Speaker Only!', and the original speaker is ruined, the cone is ripped out. Unfortunately, it seems like 20 Ohm resistance speakers were last made in the 60s and are near-impossible to find today. What's the best option for me here? I'd like the radio to work, and I've heard using the wrong resistance speaker can damage the amplifier.

[Bloo]

Look into getting it reconed. That sounds like a circuit that uses a Germanium output transistor with no output transfomer. Maybe a choke, maybe not. Nothing in the modern era is designed like that, thus the problems finding a speaker. You need the correct speaker.

 

FWIW the 20 ohms is Impedance, and that is not quite the same thing as resistance. If you measure the voice coil resistance of a 20 ohm speaker with a multimeter, it will measure a little less than 20 ohms. My wild guess is 15 or 16 ohms.

 

 

 

Edited February 22, 2020 by Bloo (see edit history)

[TerryB]

Might be easier to get the radio modified with modern internals.

[AL1630]

OK, thanks. I would prefer to keep the radio original, so reconing is probably my best option. Does anyone know of a service that they recommend?

[Bloo]

The master of the art was Hank Brazeal, probably retired now. Here are some possible sources, but I haven't used any of them. https://www.antiqueradios.com/forums/viewtopic.php?f=6&t=259926

 

[Rusty_OToole]

It's not hard to put in a new cone if you can get a suitable cone. Basically you remove the old cone, center the coil with paper shims (pieces of a business card) and glue the new cone in place. Further details and tutorials on the net or Youtube.

[GARY F]

Hemmings has that service listed.

[1963Rambler330]

I too have a 63 Rambler (American 330 Sedan). 3TBAM Bendix (but using modern radio hidden in the glove box).  I just took out the Bendix and replaced the burned out bulb on the dial window.  The radio has been unplugged since I got it. Where does the "A" lead originally connect to? Any 12volt source?  Would like great to have the light turn on (on the radio) and act like the original is powering the modern speaker/stereo. The info is hard to come by...Thanks!!

 

Lucas

[Frank DuVal]

Is there just one wire for power? If so, it just needs switched (hot when the key is in ACC if there is an ACC position other wise just hot in ON) to light the lamp. The issue is what might be wrong with the radio? If just one wire and it is hooked up to power, the radio will be ON. The radio needs to be hoked up to a speaker or other load resistor to prevent damage to the radio. Or, if the radio is already damaged in a way that blows the fuse, the light will still not work.

 

When it was apart, was there a way to wire the lamp by itself to a wire that runs out of one of the holes in the case? If so, just wire that new wire to the dash amp circuit. Bonus is this will allow the radio lamp to dim with the dash lights. Protect the new wire from chafing on the steel hole. 

 

If there are two power wires, one is already the lamp, just wire it to the dash lamps. 

 

Do you have a wiring diagram for the car?

[AL1630]

Mine is a Bendix 3TBA (Same model with push buttons). Mine only has one wire with a fuse that goes to the ACC terminal on the igniton switch. The volume control doubles as the on-off switch. Mine turns the light on with the radio.

[rocketraider]

On 2/22/2020 at 5:43 PM, AL1630 said:

OK, thanks. I would prefer to keep the radio original, so reconing is probably my best option. Does anyone know of a service that they recommend?

Jackson Speaker Service, Jackson MI. 517-789-6400

[m-mman]

Consider buying a brand new speaker with the correct OHM value.  Prices are comparable. 

http://www.turnswitch.com/

[Marty Roth]

I have used Retro Radio for several of my cars

https://retroradio.biz/

Elizabethtown, PA

Not only restore original,

but also added AM/FM,

as well as ports for accessories such as satellite radio, ipod, CD input, etc

Excellent company, and they come to Hershey

 

SEE MIKE EXPLAIN OUR SERVICES!

 

Any automobile radio from 1932 to 1982 can be (1) restored to the original manufacturer’s specifications, or (2) converted to AM/FM digital with plug in jacks to receive satellite radio, MP3, ipod or any other pluggable source of sound using the outstanding Aurora products. Bluetooth 4.1 and a USB port are also available. What you choose depends on the kind of sound you want to have. At Retro Radio, we serve to meet your audio needs while keeping the original look of the automobile radio.

On some rare radios, we make new replacement parts for the more difficult to find pieces, such as 1938 Buick dial gears, 1940 Cadillac push buttons and thumb wheels, Ford tuning shafts and other specialty items. We have a small, machine shop and urethane pressure casting quipment that enables us to make some hard to find items.