VLF,
BTW the calculated ERP is 150 uW. Quite low :-( But i will be able to
run it permanently...
The transmission is now stopped and was running from 20:45...22:30 UTC.
73, Stefan
Am 14.04.2016 23:01, schrieb DK7FC:
Hi VLF,
Since 22:45 i'm running 200 mA on 8270.0050 Hz into my antenna again.
200 mA is the limitation of this compact yoghurt-coil. The overall
system loss is about 1 kOhm, so i just need 40W to run the system at
100%. Or, in other words, power is not the limiting factor :-) There
are holes into the single yoghurt cups so there can be an air flow in
the cups. And this will be helpful/necessary in summer / daytime.
200 mA is about the current consumption of a 12V fan used in PC power
supplies. So i've constructed a plate with a fan mounted on that,
improvong the air flow. Later, a tube must be used to form a curve on
the top of the arrangement to prevent water from flowing between the
coils. Then, a forced air flow becomes necessary, normal thermal
convection could be to small.
https://dl.dropboxusercontent.com/u/19882028/VLF/20160414_214939.jpg
https://dl.dropboxusercontent.com/u/19882028/VLF/20160414_215835.jpg
A normal bridge rectifier with UF4007 diodes, then 2 ZD15 Z-diodes, a
single UF4007 diode (to reduce the voltage a bit) and a 100nF C,
that's all. It works very well and automatically :-)
73, Stefan
Am 13.04.2016 23:28, schrieb Paul Nicholson:
Sorry Stefan, nothing showing for 20:14,+30m in
555uHz. The noise floor there is 0.2 fT probably
due to all the thunderstorms in Europe tonight.
I expect your signal is down below 0.1 fT.
Also checked 20:14,+60m in 278 uHz in case you ran
for a full hour, but nothing.
Let's try again when the background is lower.
--
Paul Nicholson
--
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