Hi Chris,
Am 14.10.2015 13:35, schrieb Chris Wilson:
[...] It's far from optimal right now,
...but your first signals are better then that of many other UK stns in
the past few years (except G3KEV :-) ).
We could easily have a QRSS-3 QSO with good SNR.
Could, if i would be QRV :-(
My coil needs to be built up again. The RF litz is laying here in the
cabinet, waiting for a new body. I plan to use at least 40 cm diameter,
better 50 cm. Then i'll be on air again. The season is already there but
there are many other time consuming projects :-/
But i'm watching what you're doing and how things are developing on your
side.
Tell use the power and antenna current. I recommend to build a simple
ANALOG amperemeter, a ferrite core with high mu (AL abt 4000 nH), a
single turn primary, maybe 40 or 50 turns secondary, a bridge rectifier
(1N4148 or maybe UF5404 or similar), a 10 Ohm shunt resistor, a 100 uA
amperemeter, a 10nF C and a potentiometer and a switch. The switch is
for different ranges, maybe 1A and 5A? Calibrate it by using a dummy
load in series with a 1 Ohm resistor (metal oxide layer R is best).
Measure the voltage across the 1 Ohm resistor with the scope. Then you
know the current and can calibrate the meter.
Then you can put the meter in series to the antenna wire and align your
variometer to a maximum current. This is resonance! Once you know the
current in the wire, you can calculate the losses in the system and see
if it worth to add more ground rods or if it's better to cut the
sourrounding trees and the trees of the neighbours! :-)
73, Stefan
but I
have plans to improve things! Right now I am just fascinated by how
far it gets "as is". It's taken me ages to get this far, and the
novelty has not worn off even with a poor antenna. Hopefully one day
you might hear me out there.
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