[Lowfer] OP/OPDS tonight 137.547...

[Garry Hess]

Bob, good signals here as usual. I listened with separate setups running 
opds32, one with an e-probe and one with a loop antenna. The loop setup 
was to a Windows 7 computer and that had enough horsepower to run the 
regular opera software too.

Loop, regular opera:

05:58    136 WE2XEB Op32 -9 dB |------------------|  Fade: 0%
05:25    136 WE2XEB Op32 -11 dB    |------------- |  Fade: 4%
04:52    136 WE2XEB Op32 -11 dB    |--------------|  Fade: 0%
04:19    136 WE2XEB Op32 -12 dB    |--------------|  Fade: 1%
03:46    136 WE2XEB Op32 -14 dB    |--------------|  Fade: 25%
03:13    136 WE2XEB Op32 -18 dB    |------------  |  Fade: 5%
02:40    136 WE2XEB Op32 -22 dB    |--------------|  Fade: 1%

Loop, opds32 (internal SDR-IQ clock not recently calibrated):

2014-02-25 05:58:16 WE2XEB 934km 137546.953Hz 5mHz -20.7dBOp  92% 20.9dB
2014-02-25 05:25:21 WE2XEB 934km 137546.959Hz 10mHz -20.2dBOp 93% 21.3dB
2014-02-25 04:52:25 WE2XEB 934km 137546.962Hz 8mHz -20.3dBOp 100% 20.0dB
2014-02-25 04:19:31 WE2XEB 934km 137546.963Hz 3mHz -26.5dBOp  96% 20.7dB
2014-02-25 03:46:34 WE2XEB 934km 137546.961Hz 3mHz -26.8dBOp  59% 18.7dB
2014-02-25 03:13:39 WE2XEB 934km 137546.962Hz 4mHz -21.4dBOp  98% 20.9dB
2014-02-25 02:40:43 WE2XEB 934km 137546.962Hz 3mHz -26.9dBOp  77% 21.3dB

e-probe, opds32 (external SDR-IQ clock locked to GPS):

2014-02-25 05:58:15 WE2XEB 934km 137547.000Hz 151mHz-39.4dBOp 93% 20.0dB
2014-02-25 05:25:19 WE2XEB 934km 137547.000Hz 3mHz -37.5dBOp 100% 19.6dB
2014-02-25 04:52:23 WE2XEB 934km 137547.000Hz 6mHz -19.0dBOp  96% 20.3dB
2014-02-25 04:19:27 WE2XEB 934km 137546.998Hz 19mHz -23.8dBOp 87% 20.7dB
2014-02-25 03:46:31 WE2XEB 934km 137547.001Hz 9mHz -37.2dBOp  68% 18.7dB
2014-02-25 03:13:35 WE2XEB 934km 137547.001Hz 23mHz -36.0dBOp 99% 20.9dB
2014-02-25 02:40:39 WE2XEB 934km 137547.000Hz 14mHz -23.9dBOp 86% 20.1dB

Regular opera shows your snr improving with time. opds32 results are 
lower and for the e-probe erratic. Note the bandwidth is generally much 
larger there although the correlation values are comparable to loop 
values. I question if the eprobe XP code is working the same as it does 
on the loop windows 7 computer. There SpectraVue for the SDR-IQ and 
Spectrum Laboratory are run normally and results are passed to the 
opds32 executable running on a virtual XP machine (since opds32 is 
incompatible with Windows 7). At any rate as observed in the past it 
doesn't seem that the opds32 noise floor calculation is reliable, 
especially if a strong signl like yours is involved.
-- 
73, Garry, K3SIW, EN52ta, Elgin, IL
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