Signal handling comparisons between KiWi, WEB-888 and RX888 with PhantomSDR-Plus

[Martin G8JNJ]

Some quick tests with a Marconi 2024 signal generator, 10MHz carrier via a 10MHz BPF, Mini-circuits 4 way splitter and 6dB attenuator at -20dBm into the receiver
 
14bit KiWi MK1 2 x 10MHz = -60dBc Note that the KiWi ADC is close to clipping.
 
 
16bit WEB-888 2 x 10MHz = -63dBc Pretty close to the KiWi, despite having two more bits which should provide approx 12dB more dynamic range. I think the LNA, could be the limiting factor.
 
 
16bit RX888 and PhantomSDR-Plus, running at 82meg sample rate. 2 x 10MHz = -30dBc. I tried adjusting the gain, but it made very little difference.
 
The original message, with screen grabs, is on the NextGenSDR's IO group.

https://groups.io/g/NextGenSDRs

Regards,
 
Martin

[magicint1337]

The Smeter cant be really used, the Smeter is more like a db representation not like on kiwisdr / web888 (as these are the same)