[hpsdr] Penelope Performance Measurements

[hartfuss]

Hi,
a few days ago I did 2-tone tests with the PowerSDR test tones at 700 
and 1900 Hz on Penelope-Ozy-Atlas at 3.7 MHz with 400 mW PEP, 100 mW in 
each of the tones and found IMD3 down by more than 70 dB. 5th and 7th 
order were close and down resp. in the noise floor of the R&S ESPI 
spectrum analyzer used. Excellent!
Thanks, Hans, DL2MDQ.




  Phil Harman schrieb:
> ***** High Performance Software Defined Radio Discussion List *****
> 
> 
> After the Dayton Hamvention I had the great pleasure of spending an 
> afternoon with John, N8UR. John has a most amazing basement laboratory 
> dedicated to the measurement of all things time related.
> 
> We set up Penelope and the supporting version of PowerSDR developed by 
> Bill, KD5TFD, in John’s lab and proceeded to measure performance. The 
> plots are on the Wiki
> 
> <http://hpsdr.org/wiki/index.php?title=PENELOPE>
> 
> but here is the overall summary.
> 
> With Penny transmitting 0.25w at 14.1MHz the largest spurious response, 
> the 3rd harmonic, was down by >50dB with no external filtering.
> 
> Looking at the carrier in a 1 kHz span, all close-in spurs were greater 
> than 75 dB down.
> 
> We did some phase noise tests using John’s TSC-5120A phase noise 
> analyzer, but the Penelope on-board TCXO wasn't really stable enough to 
> get great results.
> 
> However, John suggested that the performance is significantly better 
> than any HF transmitter he had tested so far (but in fairness, there was 
> no big noisy power amplifier involved).
> 
> John believes the ‘glitch’ in the phase noise plot at 1kHz was due to 
> drift of the 10MHz TCXO in Penelope. The results were repeatable so John 
> considers the phase noise measurements to be valid.
> 
> Since we will be using basically the same FPGA code and components in 
> Mercury we can expect similar results on receive.
> 
> We seem to be living up to the ‘High Performance’ of our project title!
> 
> 73’s Phil…VK6APH
> 
> 
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