[Milsurplus] Weird Reception Of VLF Transmissions

[Roger Basford]

Hi All,

Interesting discussion on the SAQ transmissions and reception thereof. I was 
recently sent a fascinating snippet on the same theme by another UK amateur, 
see below:-


Quote/

Just wondered if you 'd heard of this phenomena. I was on a web site that 
dealt with VLF reception via the PC sound card and came across the statement 
that morse code from GBR on 16kHz had been accidentally (presumably) 
recorded along with Mike Oldfield's "Tubular Bells". So out came a CD and a 
player, duly plugged up to the PC, and sure enough...

Here's part of a Spectrogram trace: V V V GBR

(Deleted by G3VKM as it wouldn't be accepted by the server)

I then used Spectrum Lab to mix 16 kHz down to 800 Hz and pass it through a 
CW filter, the result is in the attached mp3 file. Apologies for the 
atrocious SNR but maybe with some work it could be enhanced.

The significance for me was that I could never tune 16 kHz in the days when 
GBR was in CW, I always remember it being F(M)SK and presumably encrypted 
because I could never read anything useful from it. It closed, I believe, in 
2001.

Tubular Bells was recorded in 1972 at The Manor studios in Shipton on 
Cherwell, Oxfordshire- about 35 miles as the RF flies from Rugby so you 
wouldn't think the field strength would be excessive. Poor shielding would 
generally result in hum, of which there is no evidence on Tubular Bells. So 
it's interesting to speculate about how it came to happen.

I wonder if there are any other known examples of where VLF signals were 
recorded along with music?


Unquote/


If anyone would like the mp3 file let me know, it's tiny. "Tubular Bells" 
went on to become the title music to "The Exorcist" film and made Mike 
Oldfield a rich man. The recording set-up was run by (now-Sir) Richard 
Branson who set-up Virgin Records, Airlines, Trains, went ballooning, etc.

Rugby VLF has now closed and the huge antenna system has been pulled down. 
The VLF service is now run from another TX in the north of England. 
Unfortunately, my HRO-50-T1 only goes to 50 kc, so I'll miss the SAQ event 
:-((



73 all,



Roger Basford/G3VKM 



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