Receiving SAQ on 24. Dec. 15

[Fred]

Thanks to the Crew for the Christmas message.
My Station: extern PC-soundcard connected to a Mini-Whip active antenna.
Software: Spectran. Could read the morse-code on the waterfall
S/N > 20dB in Bayreuth / Germany

Topic

[Bob Houlston G4PVB]

I was not able to receive SAQ on my PC Christmas Eve 24th December 2015 so I am working on enhancing my equipment for the next broadcast. Thank you for your transmissions and this forum where I am learning a great deal about how to receive SAQ VLF from the comments of other enthusiasts. 73 Bob Houlston G4PVB.
p.s. I am uploading, as I learn VLF knowledge, to my alternative site here: houlston.eu.pn Just scroll down the page. All comments welcome please, thank you.

[Juergen Brustat]

Hi Bob,
I just had a look at the receive diagram on your website. You didn’t really use a 22 uH coil, did you ?
Because with a 4.7 nF capacitor it would resonate at about 500 kHz . I suppose, it’s only a typing error
and should read 22 mH, which would resonate at 15.8 kHz. The 100 k resistor broadens the selectivity curve
and when we consider component tolerances, SAQ might be well included. So far, so good, but :
the input impedance of your PC is probably not greater than a few kOhms and transformed parallel
to the tuned circuit will kill any signal received. So, I recommend using another transformer,
perhaps 100k:10k or 100k:1k, and it will work.
Instead of coil + transformer you could use a second winding on the coil only.
For testing, use the Russian Alpha signals at 12 an 15 kHz. They are much weaker than SAQ,
at least in western Europe.
Wish you good success ! DL2JMB Juergen

[Juergen Brustat]

Hallo Vassily,
sorry you didn’t receive SAQ, but I am convinced this is a problem of your antenna.
The distance Sweden to Moscow is about the same as to southern France, where they had good reception.
At 17 kHz the impedance of your 20m wire antenna is very high and not properly matched to the input impedance of your computer.
So try a transformer ( perhaps 1 MOhm : 1 kOhm = 30:1) or better an active antenna amplifier ( maybe a very simple one,
depending on your local interference situation) and you’ll be happy again.
Wish you a Happy New Year 2016 (though you start that year 7 days later ?). Regards dl2jmb juergen

[F6EJU]

Great SAQ transmission well received on the French Riviera near Monaco. in JN33RV
Many thanks to the SAQ Team.
Merry Christmas.
Jean Claude F6EJU QTh : jn33Rv near Monaco the Principality.
Spectrumlab on computer and VLF amplifier , antena simple vertical HF for ham radio
See on youtube the sound and pictures.
73 de f6eju

[Mark]

I listen today the transmission RST 559 – 579, nice signal !
RX TS590SG + SO42 converter, antenna G5RV i.V. 40-10m
QTH nr Leipzig/Germany

Many thanks es vy 73 Mark – DL6YYM

[Vassily Kuznetsov]

I have been trying to listen to SAQ transmission 24.Dec 15, but could not. I have 20 meters Marconi antenna + computed ecuipped with SpectrumLab and also with SAQrx software. The signal is too low for my antenna. (I heard SAQ with this equimpent only on Christmas Eve in 2012. It was happy day)
Vassily Kuznetsov, countryside 60 km from Moscow, Russia

[Author]

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