I wonder what the level of the LNB reference (24/25MHz) of the Downconverter should be and whether it can be adjusted?
I have got the Downconverter and the modified Opticum LNB from Amsat-DL. I was never 100% happy with the receive performance though. Compared with an unmodified Opticum LTP-02H, the SNR according to SDR-Console is 6-7dB less and I can't see transponder noise using a 90cm dish.
I now also have got the DXpatrol RX set with their LNB and Reference-Injection. Using that combination, I am also getting 6-7dB better SNR.
I don't need WB RX at the moment, so I disabled the LNB Bias on the WB output and connected the DXpatrol LNB. Again, I am getting better SNR (not quite as much) but also many mix products. I guess that is due to too high reference level.
Hence my question at the top about the reference levels. Also, any idea what (if anything) might be wrong with my AMSAT-DL LNB.
Many thanks, 73