LF,
I just searched for a LF /p antenna that can be fixed in the trees of a
nearby forest. I quickly came to the pages of W1VD and saw his design of
a K9AY loop ( http://www.w1vd.com/k9ay11.pdf).
Jay, if you are still QRV here (long time ago), how well does design
perform, i.e. how many dBs can a noise source be attenuated by adjusting
the potentiometer (that changes the dynamic "resistor", i.e. the output
of the optocoupler? What angle is covered by this method?
It is an interesting idea to do it this way!
Can you give us a short report about the performance of your antenna?
I would like to arrange a fixed loop for LF receiving in the forest to
be QRV on LF without the need to carry my rather big and heavy RX loop
antenna in the car. So i could use my bike instead.
BTW, my /p LF homemade receiver using the SBL3 has only one amp stage
and the total power needed is 12V*12 mA! So i got the idea to try a
DC/DC converter to supply the RX out of the USB! This would make a heavy
battery obsolete. I took a 4.5 Euro 1W unregulated converter and added a
78L12 and 2* 100 nF. As far as i can see the converter (=SMPS) adds to
moving or broadband noise to the signal received! Good news for sceptics
about SMPS ;-)
If all works well i just need the netbook and the RX which is in the
format of 10cm x 3cm x 8cm and a /p 70cm radio to become QRV soon :-)
73, Stefan/DK7FC
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