[Milsurplus] Conelrad

[Todd, KA1KAQ]

Hi Ray -

On 12/1/05, Ray Fantini <RAFANTINI at salisbury.edu> wrote:
> This is not exactly mil radio related but it is radio. For the last
> several years I have worked part time for Clearchannel radio as a
> transmitter engineer. over that time I have had to rebuild three
> different AM sites and this included replacing old Gates ( Harris)
> transmitters of the BC-5 (5Kw) and BC-1 (1Kw) series. all of these
> transmitters were from the late forties and early fifties and were
> equipped with the dual crystal selector for the second "Conelrad"
> crystal.

I think the dual channel capability was originally meant more for
crystal or oscillator failure and perhaps adapted for Conelrad use. I
have a pair of pre-Conelrad mid/late 40s transmitters here (RA-1000 &
300G), both have dual, switchable crystal capability. I'm pretty sure
that the 300G manual actually outlines the ability to switch to the
backup oscillator in the event of a crystal crapout. My understanding
is that during a test, most stations went off the air and only those
on 1240 and 640 (620?) stayed on.

>Asked a couple of the old timers around here and no one
> remembers for certain if their were any occasions where they actually
> tested the system, their is some speculation that once a year or so they
> would do a national test and everyone would switch to that channel then
> but that would be a test with no audio, but the question I have is if
> you had to operate on the Conelrad channel don't think you would have
> much output unless your regular broadcast channel was close to the
> Conelrad channel. The narrow tuning range of the transmitters and
> antenna tuning networks would probably give you only twenty or thirty
> watts or so, and all the old transmitters I have seen have no provisions
> for a second set of networks for Conelrad.

Okay, this was a puzzler for me so I just placed a call to an old bc
engineer buddy, also named Ray (KC1BT). He told me the following:

- they ran weekly tests

- the tested involved the on/off/tone sequence and were followed by a
message telling you to tune your radio to 640 or 1240 for further
information

- re-tuning the transmitter wasn't an issue since the station would be
off the air once they completed the message and only the stations
allocated to the two Conelrad frequencies stayed on.

Our local station was/is WSKI, 1240. Their transmitter is in
Montpelier but they had studios in Barre as well, near WSNO (1450).
Ray worked for WSNO and later WORK, their FM station. We also have
WDEV 550 up in Waterbury, still sporting it's three huge  red and
white 'Eiffel' towers on the hillside along I-89.

I'd have to guess that if a transmitter had two different frequency
crystals in it and one was for Conelrad, it must have been in an area
of little or no coverage by 640 or 1240 station.

> Its amazing how almost all
> the people working in broadcasting now have no idea that this system
> ever existed, many don't remember the EBS system and the red
> authenticating envelope or how you were not allowed under penalty of law
> to open the envelope before it expired.

Not surprising really, when you look at how the technical end of the
industry has been dumbed down similar to the amatuer service. Sad,
though, for sure. There probably aren't a lot of folks in the business
as interested in this stuff as we are, and everyone knows we're crazy.
(o:

>and last but not least everyone
> has heard the story of how the Japanese were able to receive the AM
> broadcast from Hawaii and possibly use that for tracking towards Pearl
> Harbor, but is their any evidence that the Russians twenty years later
> would have used commercial broadcasting for target location? would have
> thought they had systems more advanced then that?

I suspect as Jack says, it would have been a whole lot easier. We've
heard that for years the Russians lagged behind in the technology war,
so instead of experiencing leaps and bounds forward, they simply built
better examples of the older technology, like the vacuum tube-based
comms and radar used in aircraft in the recent past. Although not as
"advanced" as ours, it was able to withstand more punishment than your
typical IC chip could. The old addage "if it ain't broke.." comes to
mind.

But as Dave asked (and I'm dying to know) - what happens to all the
old 'big iron'? Do you stash them all in a warehouse somewhere? There
aren't as many neat old transmitters left to be discovered out there
in service, backup or otherwise, as there were a few years ago, but it
sounds like a lot of fun to me!

de Todd/'Boomer'  KA1KAQ