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Jon Teske · January 26th 09, 05:23 PM posted to rec.radio.amateur.boatanchors

On 25 Jan 2009 12:50:41 -0500, (Scott Dorsey) wrote:

George McLeod wrote:
Would anyone have a circuit, or know where to find one, for the Conelrad
device as marketed by Motorola and Heathkit.

What is this device? Does it automatically tune the radio to a CONELRAD
frequency?
--scott

I lived in this era. Back in the 1950's there was a program called
CONtrol of ELectromagnetic RADiation. Subtitled CONELRAD. All AM
radios (FM was in its commercial infancy, we only had Public Stations
in the FM band) had little triangles with the Civil Defense logo at
640 Kcs and 1240 Kcs. [Kilocycles (per second) here is not accidental,
Hertz, as a term to mean cycles per second, was not adopted until the
mid-1960's.] In the event of an emergency, usually interpreted to be
an attack upon us by the Russians (this WAS the McCarthy era after
all) you were supposed to tune your AM radio to one of those two
frequencies for information on what to do. Inplicit in that was that
all other radiostations would get off the air so that they could not
be used as homing devices for attacking aircraft. The fact that there
were other methods to navigate was blithely ignored.

About 1957, CONELRAD was expanded to include amateur radio stations
and all stations were obliged by the FCC to have a CONELRAD monitor
which would tell you that an emergency was declared, that you were to
get your own station off the air, and like the rest of the population
tune to 640 or 1240 AM.

This ruling was more observed in the breach than the observance. And
few amateur stations did anything about it. [My response...I was a
teenager then...was to look for a mushroom cloud. If I saw one, I'd
get off the air. :-)

A few companies built add-on CONELRAD monitors. If I remember
correctly, you attached the device to an ordinary AM radio which was
already and always tuned to 640 or 1240 Kcs. (1240Kcs. actually
happened to be the frequency for the station in my own hometown in
Wisconsin.) When some keying signal came on, the CONELRAD monitor
would alarm and then you were to get off the air. It didn't retune any
radio to anything, it just told an alert went off as broadcast on one
of those two frequencies...at least that was all a ham version did.
In theory, you could just have a small radio playing in the background
which supposedly would tell you the same thing.

In actual tests, which were conducted from time to time, just as
Emergency Service Tests are occasionally heard now. All of a regions
stations got on one of those two frequencies (to confound the enemy's
direction finders) and they had some sort of switching so that they
all broadcast the same message from "Big Brother" but broadcast them
in some sort of rotation. The few tests that I actually heard knocked
our local station off the air, but the "emergency" broadcast itself
was total gibberish because there were too few stations in our rural
part of Wisconsin by day, and nighttime propagation was too screwy to
provide any responsible path.

I don't remember when CONELRAD died as I went off to college in 1960
and wasn't on the air very much and not at all when I was in school.
It was dead when I got back on the air with any regularity after I had
graduated..

Heathkit did indeed built such a monitoring kit. It was in the same
size box as their famous QF-1 Q mulitiplier or their earliest SWR
in-line monitor, one of the first with a Monimatch architecture. It
cost somewhere between $10 and $20 as a kit IIRC, but that was too
much allowance money for me to spend. Even as a teen, I had a keen
sense for Governmental BS (which paid off well later as I was a career
Federal Employee for 35 years in the intelligence world. You needed a
steep skirted BS filter to work in that environment.)

CONELRAD was one of the biggest governmental flops ever in the
communications arena.

Jon W3JT (K9CAH back then.)