Re: LF: VLF - G3XIZ transmitting today

[Andy Talbot <andy.g4jnt@gmail.com>]

Nothing seen at 30mHz resolution.   There are weak lines present, but six spread evenly across 20Hz display are QRM,  and nothing in the right spot.   .

 

...  going to reconfigure the SDR-IQ settings for a narrower bandwidth  ...

 

 

Andy

www.g4jnt.com

 

On 31 December 2010 11:08, Chris Osborn <g3xiz@yahoo.co.uk> wrote:

Ok Gary,

There's 50m of balloon aerial aloft now but one of the 4 ballooons has just burst.
It must have touched the wire.
Hopefully the others will hold out.

I think I may try heavier wire next time as 0.2 mm is very difficult to handle.

73 Chris XIZ

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From: Gary - G4WGT <g4wgt@tiscali.co.uk>

To: rsgb_lf_group@blacksheep.org

Sent: Fri, 31 December, 2010 10:57:06

Subject: Re: LF: VLF - G3XIZ transmitting today

Chris,

Just read the mail (1050utc) & I have adjusted my loop Rx system to your frequency running SpecLab at QRS600, 4.5mHz.

73,

Gary - G4WGT - IO83qo.

LF MF Grabber - Web Site - Blogspot - 9kHz Grabber

On 31 December 2010 10:07, Chris Osborn <g3xiz@yahoo.co.uk> wrote:

All noted Andy.

The aerial current is about 0.15A
The frequency is drifting slightly due to shack cooling and is now
8.971 870 kHz

I'll try the balloon aerial in about half an hour then switch to slow QRSS.

73 Chris XIZ

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From: Andy Talbot <andy.g4jnt@gmail.com>
To: rsgb_lf_group@blacksheep.org
Sent: Fri, 31 December, 2010 9:43:41
Subject: Re: LF: VLF - G3XIZ transmitting today

Thinking about that -

Its exactly what I did with my first 73khz SLOWCW Tx  prog back in 1997.   SLOWCW was generated, and a part of the 'mark' signal consisted of the callsign being sent at normal CW speeds for identification.   G3PLX could see this fast CW on his received warerfall as a definte reduction in carrier power.

 

On 31 December 2010 09:39, Andy Talbot <andy.g4jnt@gmail.com> wrote:

SDR-IQ is running, with a 20Hz wide waterfall looking in 0.03Hz FFT bin size.

It took 5 minutes for a calibration signal to show up on the screen.

The paint is drying - slowly :-)0

 

If you want to send QRSS identifier at high speeds (relative) , suggest you repeat at 10 or 15 minute regular intervals.  They will then show up up as periodic reductions in carrier level of about 3dB or so.

 

If fact, tht just may be a suitable task for a new bit of software or a PIC - a mixed QRSSSSSS generator

 

 

Andy

www.g4jnt.com

 

On 31 December 2010 08:44, Chris Osborn <g3xiz@yahoo.co.uk> wrote:

LF,

I shall be transmitting VLF today starting at 09.00 Z

Freq:    8.971 855 kHz (nominal but close)
Mode : Continuous carrier with occasional QRSS identifier
Aerial:  Initially:  40m inverted 'L' at 10m 
           Later:     balloon supported aerial at 50m

Hopefully the system will keep going as the loading coil re-wind
seems to have done the trick now that the varnish has dried.

73
Chris
G3XIZ

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