Disc Demodulator ?????

[walter duque]

I am cleaning house and I found a Panasonic CD-4 System Disc Demodulator (4 Ch Radar) Does anyone remember what that was used for, because I sure can't.

 

[markw]

It was used for quadrophonic records. It "demodulated" four discrete channels from a vinyl disc cut with the CD-4 system which "multiplexed" two additional channels in the two available physical channels on a record by recording them at frequencies between (approximately) 20khz and 40khz. These required special cartridges that would respond up to 45 khz and this demodulater to which you refer.

Here. I googled a little history for ya. Read it and learn.

 

[walter duque]

Thanks markw
Great link, I guess that goes in the dumpster, although it looks like new. I did use the Marantz4400 with the O-scope at the time. It's been a long time ago, I think 1974.

 

[TLS Guy]

Thanks markw
Great link, I guess that goes in the dumpster, although it looks like new. I did use the Marantz4400 with the O-scope at the time. It's been a long time ago, I think 1974.

Don't put it in the dumpster. That is a really rare item. Sell it on eBay. There may be a collector restorer out there who needs it badly. A museum might be in need of it also.

Gear that unusual should NEVER go to the dump.