LF, Hello all!
I plan to run a test transmission on 136kHz during Friday, Saturday and Sunday
night. The setup is very preliminary/temporary and can not be left unattended
for longer periods. The unprotected ATU has to be brought indoors when not in
use. We expect cold dry weather for the weekend so it should survive while in
use. The estimated ERP based on tests made yesterday is only 20mW. This figure
does not include absorption in nearby objects.
Initially the transmission will be CW only but QRSS3 with CW ID will follow as
soon as I have the ON7YD keyer software and interface set up.
Antenna: Inverted-L 15m high with 35m horizontal wire. 20 radials 5-25m long,
half of them terminated in 0.5m deep earth rods. Rtot estimated to roughly
100ohms.
ATU: Variometer + large loading coil
TX: Keyed 1W 50ohm DDS signal generator feeding a pair of parallell 807's in
class AB1 trough a wideband 1:5 voltage stepup transformer providing 80Vp-p for
the control grids. Classic parallel tuned tank with adjustable coupling coil.
Power output is measured to 65W at 810V/150mA on the plates.
Unless I receive other suggestions for the QRG that will enable QRM-free QRSS
reception for interested stations the frequency will be 136.40kHz.
I can not receive on 136kHz during this test. I will inform when QRV/QRT.
Best regards
Paul-Henrik / OH1LSQ
Vaasa / KP03SD
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