[Boatanchors] Morrow CM-1 CONELRAD Radio

[Gary Peterson]

I started working in broadcasting in 1965.  To activate downstream CONELRAD receivers, the station dropped carrier for ten seconds and returned to the air with a tone (1,000 cps, as I recall) for ten seconds.  If it was a weekly test, normal programming resumed.  If it was World War III, the station either signed off or would QSY to 640 or 1240 kc, depending on their status.  Many CONELRAD receivers, such as the Kaar Conalert that I still have, would light a front panel red lamp, operate a relay for outboard signaling and unmute speaker audio.  One would hear the tone following the carrier drop and the subsequent announcement that it was, hopefully, a test.

I also have a Morrow CM-1.  The Morrow detects the absence of a carrier by having the front panel meter reading drop and the relay and tube, if installed, may operate an external light, bell or some other signaling device.  If one was present, the volume could be turned up and the tone and any announcement could be heard.   The Morrow is actually a hot little AM BC receiver.  It picks up distant stations with the little rat tail wire antenna.  Both of my Morrows came without the extra tube and relay.  I added the extra tube and relay to one of them and it works exactly like it should.

To test the Morrow, tune in a local station, while monitoring the relay contacts. Then, tune to an empty spot on the dial.  The relay should flip to the other state, within seconds, along with the decrease in  panel meter reading.

Gary
K zero CX   

My local radio group has procured a working Morrow CM-1 CONELRAD Receiver
in pristine condition.

How can we simulate a CONELRAD signal to activate the relay in the radio?
Howie WA3MCK