LF,
Just for fun and entertainment i want to share my todays work and show a
picture of the bandpass i have now arranged in my LF PA. 60x0.1mm RF
litz wire is used on some T200-2 cores, the caps are Wima FKP-1 2 kV
types. There is also a blue large ferrite core visible that makes the
decoupling from the mains voltage and impedance matching. It has a 1 uF
cap in series for DC decoupling, to be replaced later by a resonant LC
circuit. Coming from the antenna cable which is RG214 type there is a
parallel LC to ground, then a series LC in series to the xfmr. From the
series and parallel coils i will soon decouple some RF to drive a phase
meter showing if i am on resonance. In the next step, the drive engine
which is on the roof now will be steered with a circuit connected to the
phase meter. It will keep the system in resonance in case of sudden
rainfall, which changes my resonance strongly, due to the high Q of the
new glass/RF-litz coil which must be in the range of 1000!
http://dl.dropbox.com/u/19882028/LF/DSC04272.JPG
Nice hobby for cold and dark days :-)
73, Stefan/DK7FC
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