Re: LF: Re: Testing now a new RX antenna on MF... and DK7FCs garden progress ;-)

[DK7FC <73dk7fc@googlemail.com>]

Hello André,

Fine fine! For the tests it may be useful to do QRP here so the SNR drops to negative values on your side (?). Or do you need the 40 dB dynamic range of WSPR for the tests?

Well, 2 days ago i planned to come on air with the new RX antenna. But again it took several hours to remove greenery and stuff just to reach the location below the tree where i wanted to hang up the second end of the T antenna.
But now, today everything worked well and the antenna is now lifted and fixed in its final position. Total length of wire is about 20m (guess 100...150 pF) and height above ground is 6...15m. Effective height could be 8m. I hammered a ground rod into the stony soil, 1,2m deep :-)

Tomorrow i will start doing measurements and matching to 475 kHz / 50 Ohm. I expect losses of 100...150 Ohm so it will not be a efficient TX antenna. However i expect it will be an excellent RX antenna which is the actual goal :-) Looking forward to that :-) Thus i will stop TXing WSPR on MF next afternoon because i need the equipment in the garden... Then, maybe, you will catch a weak signal on MF from JN49IK24.

73, Stefan/DK7FC



Am 08.08.2014 10:55, schrieb André Guyé:

Hello Stefan,

 

I’ll try many other tests to day and saturday at day time, including :

• a 45° change in the K9AY direction of the 4 support wires ;
• an extra relay system to use only one of the two out of phase verticals. That means it can works also as a single vertical monopole.

Note : I have still the terrific local QRM carrier running on 475725 kHz, so I need to use a 100 Hz filter to kill it, or I copy nothing.... Of course, using such a sharp DSP filter here, means that the S/N reports ts not realist here. But, the relative values are the most important in this test, even you know that the WSPR S/N is not linear for positives values.

 

73, F6CNI.

 

From: Guyé André

Sent: Wednesday, August 6, 2014 11:48 AM

To: rsgb_lf_group@blacksheep.org

Subject: LF: Re: Testing now a new RX antenna on MF

 

Hello Stefan.

 

I just start my RX now, hunting at your signal.

 

I’ll test the both antennas K9AY (in the 4 possible directions) and the 2 els out of phase verticals, to see the diferences. On day time your signal is stable + / – 1 dB.

 

So, more info in the evening.

 

73 F6CNI

 

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