The first sample I got fell in the category “Close, but no cigar”. Harmonic suppression was a bit disappointing, and the unreliable rotary encoders were a nightmare. The receiver however was a dream – sensitive yet selective, and an excellent front end.
Today I received an updated version of the KG-UV920R, the KG-UV920P. I can keep the radio for only 2 days, which doesn’t give me much time. Instead of doing all the tests myself, I packed both the Wouxun radio plus the Rigol DSA-815TG spectrum analyzer and went to Tom PA2TSL. This gave me not only the opportunity to tap into Tom’s extensive knowledge, but also to cross-check the results of both our spectrum analyzers. Results were 100% identical, which is good to know. We also looked at the sensitivity again.
“Yes we can!” must have been the slogan at the Wouxun R&D department, because they fixed all major problems (not sure if Obama was involved though). Just a few minor niggles remain, but more about that tomorrow. A quick overview of the differences:
Sensitivity @ 145MHz
Old version: -128 dBm
New version: -127 dBm
Sensitivity @ 435MHz:
Old version: -125 dBm
New version: -126 dBm
Insignificant differences, which can be attributed to either standard fault margins, or slight differences in the accuracy of the test equipment used (Marconi vs HP).
Harmonic suppression @ 145 MHz:
Old version second harmonic: 47 dB down
New version second harmonic: 64 dB down
Harmonic suppression @ 435 MHz:
Old version second harmonic: 54 dB down
New version second harmonic: 65 dB down or better (at 35 Watts we ended up at almost 70 dB down)
Third harmonics were undetectable on both bands.
We were more or less astonished – from below average to one of the best isn’t something we expected. 60 dB down on both bands would already have been excellent, but Wouxun went even further.
Fixed. Period. No strange, unpredictable behavior anymore.
No pictures yet, no time, sorry. I’ll try to make some tomorrow.