[Lowfer] 29.5 kHz historical

[Lee]

Verey interesting. Thank you for that.
Lee


-----Original Message-----
>From: "David L. Wilson" <dwilson314 at verizon.net>
>Sent: Mar 6, 2014 7:56 PM
>To: "'Discussion of the Lowfer (US, European, &amp;	UK) and MedFer bands'" <lowfer at mailman.qth.net>
>Subject: [Lowfer] 29.5 kHz historical
>
>With WH2XBA/2 on 29.499 kHz, I thought I would give a little history of 29.5
>KHz, 1 kHz away.  Back around 1970 or so when I first tuned there using a
>converter I built with a 6BE6 tube feeding an E. H. Scott 20 tube "antique"
>radio I bought for $10 at a flea market and a 50 ft antenna, I found a
>signal centered on 34.5 kHz (later moved to 29.5 kHz --se below).  The radio
>had a "tuning" push button that I fastened down--in reality the "tuning" was
>a BFO which fortunately allow ssb, cw, and RTTY operation though it was not
>designed for that.   The signal on 34.5 kHz sounded like FSK cw and for
>hours would what sounded like "VE  ES" in cw and occasionally longer
>messages that which others identified as encrypted cw.  I built a loop
>antenna from 3 ft lengths of telephone wire with literally hundreds of
>splices and DF'ed the signal to the west.   I lived in Ohio at the time and
>conjectured the transmission came from the Strategic Air Command (SAC) in
>Nebraska.   I wrote them a letter and they denied it was them.   After a
>year of more DF'ing, I was convinced it was them, and writing them again,
>they confirmed this time and sent me information identifying the
>transmission as being from the SLFCS (Survivable Low Frequency Communication
>System) station in Silver Creek, NE with 110 kW.   They operated a second
>station at Hawes, CA on 37.2 kHz.   About that time, I acquired a new
>surplused NSA ink-paper recorder.   I hooked that up and recorded the
>transmission to the paper strip (I still have a piece of that from that
>effort).  Splattering ink around my bedroom, I was able to discover what I
>was seeing was 5 (not a typo) Bd 50 Hz shift Baudot RTTY.  The "VE ES" was 5
>Bd Baudot RY's with some blank characters inserted.   This station later
>moved to 29.5 kHz and later 48.5 kHz before it and the Hawes CA also were
>shut down.   Besides 5 Bd Baudot, they also used 50 Bd  FSK Baudot and 200
>Bd MSK.  They would transmit messages in all 3 modes (similar to what TACAMO
>does today but TACAMO uses a 400 Bd MSK for the third mode instead of 5 Bd
>FSK).  I have not seen anyone else besides these two stations use 5 Bd.  So
>the current slow modes used on 29.499 take me back yeasrs ago to when I
>copied 5 Bd/50 Hz shift Baudot centered just 1 Hz away on 29.5 kHz.
>
>The 5 Bd mode was obviously chosen for similar reasons as some of the modes
>being experimented with today.
>--
>David L. Wilson
>
>
>
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