Hi all. I am new to this group. I recently bought a nanovna off Ebay. It's a black one, set up for 900MHz and 2 traces. It will not measure S21. All I get is noise at +/-10dB peak levels. S11 works just fine. Should all nanovna units be able to measure S21 regardless of being a "antenna analyzer" or "vector network analyzer". BTW, what is the difference? Of what value is the 4-trace version? I read that in order to flash a 4-trace firmware onto a 2-trace unit, the pgm needs to be unloaded? I tried upgrading the firmware, installing the boot-loader and I found 3 versions of firmware. The boot-loader seems to work fine, sees the device but when I try to load a firmware file, I get a message "not correct format" or something like that. Both softwares used for operating the unit work OK. Should I send this one back and buy a new one or have I not done something I should have? I am not a programmer. I would like to turn the switch on and use it. Thanks.
Ken
