Hello Wolf, all,
my antenna is a 22m long and 11m high "lazy-L" (= marconi antenna with topload).
It is surrounded by many trees, in fact some trees act as support.
The loss resistance varies from 70 Ohm in summer to 30 Ohm in winter (if it is freezing for some
days).
To that I have to add +/- 5 Ohm variometer loss.
Fortunately we have a 5 W EIRP limit on 472kHz, so any losses can be compensated by increasing
power ;-)
73, Rik ON7YD - OR7T
Hello Andy,
Thanks for the info. That's a very nice antenna (larger than what I use here at the moment), and a base impedance of 18 - j * 560 Ohm is really impressive. When I put the antenna at DF0WD into service some years ago (total wire length ~60 meters, 11 to 15 meters
above ground, and with the radial system fully intact) I thought that a resistive component of approx 26 Ohm was "good". Now its more around 30 Ohm, and before laying out two new radials (partially under the grass) it was 35 Ohm i.e. quite lossy.
Wonder what others with comparable antennas (the 'Marconi' type, or vertical wire with a lot of topload) are measuring.
Have a nice weekend,
Wolf DL4YHF .
Am 31.01.2014 10:58, schrieb André Guyé:
Merci Wolf.
A nice QSO with you. I am still on QRP configuration, using a 3 Watts output TX. HI. I like very much QRP.
The antenna is an Inv L base loading. Total wire length is 80 meters, and the horizontal wire is 12 meters up. The feeding base impedance is ( 18 - 560 j ). It needs a 190 µH serial coil to resonate.
Best 73 de Andy, F6CNI.
Sent: Thursday, January 30, 2014 8:27 PM
Subject: Re: LF: France QRV - JT9 on 630m
Merci Andy,
SNR during your CQ call was -16 dB (in 2.7 kHz, I presume), later dropped to -25 during the QSO.
Would have been ok for CW if there had not been the qsb ;-)
Now IZ7SLZ and I5EFO in JT9-1 on qrg, both around -20 dB here.
73,
Wolf DL4YHF
JO42FD
Am 30.01.2014 17:57, schrieb André Guyé:
F6CNI also be QRV this evening JT9.
73 de Andy
Sent: Thursday, January 30, 2014 5:52 PM
Subject: LF: CQ CQ F4DTL JT9 on 630m
Rendez vous at 2100
GMT this evening
F4DTL Nicolas JN18FP
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