[Lowfer] 29.5 kHz historical

[Graham]

David,

Very interesting story.

Did that "surplused NSA ink-paper recorder " use a paper tape about 3/8" 
wide was made by Hellscriber?

cheers, Graham



On 2014-03-07 02:56, David L. Wilson wrote:
> 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
>
>
>
> ______________________________________________________________
> Lowfer mailing list
> Home: http://mailman.qth.net/mailman/listinfo/lowfer
> Help: http://mailman.qth.net/mmfaq.htm
> Post: mailto:Lowfer at mailman.qth.net
> Post must be less than 50KB total for message plus attachment!
>
> This list hosted by: http://www.qsl.net
> Please help support this email list: http://www.qsl.net/donate.html