Attempting to bench test a 1964 J88 AM radio

Terminals on the back seem easy enough
Power, speaker, unused? ground
Hooked battery - to radio case and gm speaker of dubious quality
Hooked radio spkr wire to spkr other wire
Battery + to radio 12V
Result: light comes on, some bit of static in spkr when fiddling with fader ****, but no stations at all. Added "antenna" by means of a 4 ft long wire in the antenna wire hole to the center of the contact. Not better.

Changed dubious 1970 Cutlass spkr [which made not even a click when 12 applied directly to its wires] with a known good house radio speaker- maybe not 10 ohms impedance, but good for testing, right?
Result, same- light, but no station sounds.

Am I doing something wrong?
Battery is out of my truck, seems OK
I do not seem to be able to find any of the actual car antennas that I have stashed. Is a 1964 AM radio fixable?

 

You can buy a can of tuner cleaner and spray it into the shaft areas of the radio and work them back and forth to clean the contacts and probably stop the staticy sounds you are getting when you turn the *****. The antenna is of some importance although you probably tried what I would have guessed would be enough of an antenna to get something to come in. I don't know what a working 1964 J88 AM Radio is worth but it's hard to get anything electronic fixed for less than $150.

 

Thinking a little more about it, some old tuners like you describe had a simple string that acted like a "belt" to move the tuner itself inside the radio. You might be able to just open it up and see it the string is broken, it might be a simple do it yourself fix.

 

If your working under a fluorescent light you will get a lot of static. Spray the electronics cleaner into the back of the volume control. Am radio signals will not penetrate into structures very well through a car antenna. A 10 ohm speaker will work fine. If it has a fader there are 2 speaker wires (front and rear).

 

update:
She's pretty dead
I was pretty sure I had it set up enough for testing, but illumination was the extent of the activity, and only half the time at that.

Pulled a '68 AM in from the garage, real nice condition, hooked that up.
It made nice radio sounds with a wire for an antenna, not much w/o an antenna.

The '64 indicator moves back and forth OK
no amount of fiddling with antenna in the socket attained joy though

Pulled f/r fader, cleaned it, replaced it with the jumper from the '68 radio
same result- nada

put everything back the way it was, and currently have it left on for a few minutes, to see if that helps. Looks dusty inside though, and probably just died of old age.

 

Aren't there 2 pos wires for the front and rear speaker and the speaker neg's go to chassis grnd?

 

It could have had a floating ground, but one lead and a ground should get some kind of signal. Are you suggesting hooking up one of the spkr wire leads and touch the other to the radio chassis? Might work if you're right, won't hurt.

 

Yes, then turn the fader back and forth.

 

Faders are failure prone, if you still get nothing, bypass the fader and just direct signal to the one speaker from the leads that feed into the fader.

 

update:
After leaving it on for a while and making a better antenna connection by folding the wire back into a V with 2x the thickness, I was able to get some stations. I was surprised to hear it play only songs from 1964 and earlier!

With only 1 wire for each speaker out of the radio, they must have used the chassis for return ground. My test speakers [first one was dead, said it was from '72 Cutlass] had 2 wires, so one was connected to battery minus.

There is a "GND" terminal on the radio but it appears to be unused and never has been. Pretty sure they ground thru the dash/ chassis for 1964.

 

Glad it works.

 

I was surprised to hear it play only songs from 1964 and earlier!

Cute. I sold a television to a very elderly woman years ago that called me at the store with a complaint about the new TV. She said it had more commercials than her old one. I had no idea how to reply to her.

 

It's an old radio, therefore it plays old songs.

 

on any car A.M. radio of old, there will be an antenna trimmer screw somewhere next to the antenna jack. Look through any holes in the chassis near the antenna to find it. Trim for loudest reception on any station you can pick up.
After that, a second trim on a weak station to optimize.
This is only for the A.M. radio.
If it is a combo AM/FM, it only works for the AM half. There is no trimmer for the FM.

George