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[linrad] RE: question regarding LINRAD
I have not thought about it. It would be another complication
For optimum operation you should place the noise floor equally for
both channels. This should be done in hardware for dynamic range reasons
but fine adjustment within a couple of dB could be done in Linrad.
That would be another parameter: "Noise floor balance".
Then you need to know the gain of the two channels and differences
between preamp noise figures and noise pick-up has to be known and
added to antenna gain differences. In a good system these factors
can be neglected but with very different antennas differences in
the noise temperature could be as lerge as the gain difference.
With a X-yagi system using identical antennas for +45 and -45 degrees
it is all very simple because signals with close to perfect
H polarisation are easily available. They allow accurate calibration
of everything. In a + configuration accurate calibration is very
difficult because there is no way to produce a 45 degree test signal.
Ground reflections make it close to impossible unless you have
high towers for test antennas with 45 degree polarisation and good
I have not decided anything at the moment. Right now I am working
on mounting methods for my next antenna. Simulations with stacking
harness and towers are time-consuming.......
Leif / SM5BSZ