Hello Markus,
Since 17:38 UTC i'm again TXing each 10 minutes. Now the wire is
configured as a dipole on the ground. For resonating a switchable
inductor was available. I took the maximum value of 300 uH which leads
to a clear increase of the antenna current and a good looking current
wave form. But it seems not to be the optimum. Also the transformer
could be further optimised. Now the PA takes 0.85 A, yesterday it was
1.05 A. So the TX power should be a bit lower now. I measured 220 mA
(rms) antenna current, -1.5 dB less than yesterday.
As you say, the efficiency seems to be worse. But maybe there will be
an interesting difference in the night propagation results.
I will run the transmissions until about 7 UTC and then finish the
experiment.
Thanks again to all reporting stations.
73, Stefan
Am 09.09.2018 19:46, schrieb Markus Vester:
Hi
Stefan,
the three transmissions after 17:24 were about 2.5 uV/m here, i.e. 6 dB
less than the prior configuration. But this may depend on direction.
Best 73,
Markus
-----Ursprüngliche Mitteilung-----
Von: DK7FC <[email protected]>
An: rsgb_lf_group <[email protected]>
Verschickt: So, 9. Sept 2018 18:50
Betreff: Re: LF: Re: 137 kHz WSPR-2 on a 900m long ground loop, this
weekend
LF,
I will no disconnect the grounded ends of the antenna and try to match
it as a dipole. No idea if this will work with the components i have
available here. But i think i will come backon air later...
73, Stefan
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