ON7UN Amateur Radio
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Measurements on the round septum feed:

Both 13 and 23 cm feeds have been measured in the Anechoic chamber in Prague. The test results where compared with the moddelling software, and matched the calculated results.

Following is the result of return loss and isolation. Compare this calculated result, with the measured results in this pdf file:

return loss and isolation measurements

Following is a measurement of sun noise, with a 23 cm round septum feed and super VE4MA choke ring. I had to increase the efficency to 65 % to match the measurement. With 90 SFI ,18 dB sun noise was repeatably measured with a 6,1m reflector, 0,21 dB NF LNA, and 0,1 dB losses before the LNA. I also measured the complete setup for NF including adaptors and relay, resulting in 0,32 dB NF. Comparing the result with 0 dB in front of the LNA, and including 0,34 dB NF gave the same result.In this pdf file you find the two simulations with VK3UM emecalc software :

VK3UM simulations

13 CM feed measurements:

Return loss of the RX port markers on 2304 , 2320 and 2424 MHz

Return loss at the TX port

Isolation TX - RX

Still under construction, more to follow



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