> 15:15 UTC on 136.175 kHz, i bet this was your signal! ;-)
Could be? Carrier on air 136.175 kHz intermittent since 16:40,
continuous since 16:54 and later will move to a frequency in
the OPDS band for some EbNaut.
236W DC input.
Instant LF coupling transformer: rummage in the shed until
you find a 50 metre coil of 3-core heavy duty mains cable.
Diameter about 40cm, turns 40.
Each wire measures 630uH with the other wires open circuit.
With one wire shorted, the other wires measure 45uH each.
I think that's not bad and the leakage inductance is half of
what I need to tune the antenna anyway. I just needed a small
extra coil to bring it into tune. Found a small coil of heavy
loudspeaker cable - about the right inductance, wired it in
series and bingo! Tunes 136 very nicely. So, I didn't actually
have to wind anything in the end.
Near the end of the coax a stream emerges from the ground in
a muddy patch. I pushed some scrap copper pipes into the mud.
Three good stakes a few metres apart. Instant ground terminal.
I'm getting to like LF - you can take some liberties. Coils of
mains cable as transformers, terminal blocks as RF connectors,
buckets of salty water for dummy loads.
--
Paul Nicholson
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