Dear all,
a short overview of my first night on 600m:
- 4 stations worked: G3AQC, GM4SLV (1100km), G3ZWH and G3WCB in that order
- reception reports from OH (OH1LSQ, 1680km), SM, DL, SP, OK, PA
- heard but not worked: DI2AM (599) and SM6BHZ (599+)
As the UK NoV's might expire by the end of February I tried to get
QRV asap, with a very "experimental" and temporary station:
TX: clone of the M0MBU 4MHz VXO design with a modified 136kHz PA. The
PA is causing some trouble, efficiency is lousy (40%) and the FET's
are getting very hot during transmission, so I keep the TX periods
short. Output = 120 W.
Antenna: 9m high / 25m long T-antenna with a part of the loading coil
at the top. Calculated Rrad = 0.3 Ohm. Antenna current is 1.4 A, so
theoretical ERP should be about 0.6 W. But due to the many trees
close to the antenna (some only about 2m) I guess that my real ERP is
far less, maybe 0.3 W.
Based on 120 W / 1.4 A the loss resistance is about 60 Ohm
Antenna tuning and variometer are in open air, so for no no operation
when it is raining.
I will try to be QRV with this setup during the next weeks (to get
interested UK NoV's one step closer to their DXCC .... ..) and
meanwhile I will try to
- build a proper high efficiency TX (I aim for 400 W)
- improve ground to reduce the losses (I aim for 40 Ohm)
That should improve my signal by about 7 dB (1.5 W ERP).
73, Rik ON7YD (and OR7T)
Disclaimer: http://www.kuleuven.be/cwis/email_disclaimer.htm
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