Hello Albert, LF,
Saw you testing today but haven't given you a call. Tmw i will repair my
RX.
Today i completed the LF matching unit on the institutes roof. Now there
are 2 cables where is get 50 Ohms at 137 kHz :-)) The first time i have
a FIXED efficient LF antenna. Due to the very high Q of the system, i
can and have to fine tune the system by a simple variometer (some 10 uH)
in the shack.
I am using a primary coupling coil to inject the power into the main
coil. This allows best galvanic decoupling and protection in case of a
lightning strike (the antenna cannot be pulled down when thunderstorms
come off but is designed (IEC60xxx) to withstand a direct lightning
strike...).
Nothing new of course, but maybe giving some ideas / imaginations to
others who are new on LF...
Some photos of the final arrangement (hopefully):
http://dl.dropbox.com/u/19882028/LF/CAT%205%20cable%20for%20LF%20TX.JPG
http://dl.dropbox.com/u/19882028/LF/primary%20coil.JPG
http://dl.dropbox.com/u/19882028/LF/PTFE%20plate%20to%20separate.JPG
http://dl.dropbox.com/u/19882028/LF/main%20coil%20and%20feeder.JPG
http://dl.dropbox.com/u/19882028/LF/complete%20arrangement.JPG
73, Stefan/DK7FC
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