50's car record player

[ron carpenter]

I need help.I have this car record player,made in the late 50's early 60's. mechanicaly I have it working fine,by accident I reversed the polarity.I burned up the device that went to the car AM antenna .The Connection y'd into motorola antenna plug.There were two wires from the needle cartridge,12 volt +/-,and a shielded wire to the antenna .This is going into a very nice restored carwith only an am radio.The device was all sealed in some kind of resin material making it impossible to repair.I am not experienced in electronics, and having a tough time here. If I had help, I could build something myself, or if anyone knows of something out there that could be purchased and made to work, I would appreciate hearing about it. Thanks, Ron

 

[The Mad Professor]

Hi Ron,
repairing the original electronics could be done but it would be a labor of love akin to the restoration of the vehicle. It could be done though, spares could be sourced and the original circuit reverse engineered.

What I would suggest is re-casing more modern electronics from a equivalent portable stereo inside the existing vintage case. This moves it from the realm of electronics into the mechanical where you should feel more comfortable.

 

[Externet]

If the turtable output is already about 1MHz AM; whatever is inside the mystery box could be replaced by a tiny 12V relay; Common to the radio antenna coaxial conductor; Normally Open to the turntable output coaxial; Normally Closed to the antenna coaxial.

When the turntable be on, a wire energizes the relay passing the RF to the radio.

If the mistery box is the RF generator/modulator with only audio from the needle and power input; there has to be a schematic on the web to make one.

Miguel

 

[ron carpenter]

thanks

Thanks for the response.I did open up the black box,small psb two metal transistors,tunable coil,six resistores,ceramic capasator and a black thing?maybe another resistor (3/16 in. dia 1/2 in. long with a wire out each end).there are no markings on any thing because I used lacquer thinner to soften encasement so I could get inside.I tried to find out what the transistors were but no luck,there are three rows of two numbers and letters.1st transistor 3d,1d,gd;2nd transistor 5d,1d,gd. the resistors i could remove and measure if they are not burned.The cap I have never measured one before.The coil I damaged removing the junk they sealed it all in(a few of the very small cloth rapped wires are broken).

 

[Externet]

Try building this one :

**broken link removed**

Eliminate R1, and substitute the microphone (violet) with the capsule wires.

For sure there is more on the net, but that seems simple enough. Good luck,
Miguel