Re: LF: Now using Mini Whip here on 8970 Hz in JO33kh, Appingedam

[wolf_dl4yhf <dl4yhf@freenet.de>]

Hi Peter,

you could check the calibration later (after the tests on 8.97 kHz) by temporarily switching the spectrogram's center frequency to 11.904761 kHz (Russian 'Alpha' on that frequency is currently active). It's not an ideal check because of the periodic signal -> fence-like spectrum, but maybe the MSK transmitter on 20.9 kHz is not such an ideal source. Anyway I will check it with the GPS-disciplined receiver, if FTA is really 'spot on' frequency.

All the best,
   Wolf DL4YHF .

P.S. Suitable GPS receivers (with low jitter on the PPS output) are quite affordable now. I use a Garmin GPS 18x LVC, which is sensivite enough to be operated indoors. It used to be available (or still is) at RS Components and other distributors. The receiver doesn't need to have a 10 kHz output; a low-jitter PPS output (one pulse per second) is sufficient to compensate the soundcard's sampling rate continuously, and provide a very accurate timestamp for other experiments.


Am 23.03.2012 23:00, schrieb PA1SDB, Peter:

Hi Eddie,

I have set that 'Sampling rate detector" in SL.

I use 20k9 FTA, the indicator is Green, I have Enabled it.

What els have I to do ????

 

I use that Bandpas filter in the left Black box.

8970 Hz center, 500 Hz width.

Spectrum on L2

 

FTT input size is 524288

Decimal input by is 216

 

That gives:

 

Effect of FFT settings with fs= 48.0000 kHz:
Width of one FFT-bin: 423.855 uHz
Equiv. noise bandwidth: 635.783 uHz
Max freq range: 8.91444 kHz .. 9.02556 kHz
FFT window time: 2359.296 s
Overlap from scroll interval: 87.5 %

I did not callibrate it somehow. On 30 meters / QRSS I use that time sign on 9996 KHz. I don't know how to callibrate it on VLF.

I can't whistler that stable :-) 

 

That signal on 8.969,995 has a kund of fading. I hope it's not something local.

 

Feel free to inform me if I do somnething totaly wrong !

No hard feelings :-)

 

 

73's Peter - PA1SDB

 

 

 

----- Original Message -----

From: qrss

To: rsgb_lf_group@blacksheep.org

Sent: Friday, March 23, 2012 8:51 PM

Subject: Re: LF: Now using Mini Whip here on 8970 Hz in JO33kh, Appingedam

Peter

Very good, how is your calibration? Henny is on 8.97000 you have a line at 8.96995 if it stops at 23.00 that is when Henny is QRT.

73 Eddie G3ZJO


On 23/03/2012 19:59, PA1SDB, Peter wrote:

Hello all,

Today I did plant the "PA0RDT Mini-Whip" antenna in the backyard at about 20 meters from the house and 4 meters above ground level.

 

Last 2 week I was using 2 pasive loop antenna's who where connected direct into the mike input.

That wasn't a succes...

 

I hope to see some results soon :-)

 

Take a look at the links below. I did start logging on Friday evening at about 19:00 UTC, so perhaps I have to adjust contrast later.

A page on QSL net http://www.qsl.net/pa1sdb  or direct to the grabber schreen plot http://home.deds.nl/~knol/dream.jpg

 

73's, Peter - PA1SDB

 

QTH is Appingedam in JO33kh, in the very North- East part of The Netherlands.