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Old 27-Nov-2020, 10:52 PM   #88
rabbit73
Retired A/V Tech
 
Join Date: Aug 2012
Location: S.E. VA
Posts: 2,747
Quote:
Originally Posted by tripelo View Post
Looks like displays from three different STL-SDR units,
that is if the RTLSDR Scanner is running on one of the lower cost devices?
That is correct. The last three images were:
1. RTL-SDR.COM V3 dongle with free open-source Scanner software from GitHub
2. SDRplay RSP1A SDR with SDRuno software
3. Airspy R2 SDR with Spectrum Spy software that is included with the SDR# (SDRsharp) software download
Quote:
When comparing the SDRplay and the Airspy,
noticed the noise spectrum on the lower frequency side of Channel 3 is different for each.

Specifically, the noise is increasing near lower edge of Ch3 for the SDRplay,
for the Airspy decreases a bit near lower edge of Ch 3.
Yes; three factors account for that:
1. The noise floor is not constant on VHF, especially VHF-Low; the scans were done at different times
2. The RSP1A with the SDRuno software is limited to a useful bandwidth of about 8 MHz; each side falls off pretty fast. The Airspy R2 with the Spectrum Spy software has an extremely wide bandwidth for a scan only limited to the full bandwidth of the R2.
3. The bandwidth of the antenna

Attached Images
File Type: jpg Spectrum Spy Full Scan_1.jpg (90.7 KB, 3395 views)
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Last edited by rabbit73; 27-Nov-2020 at 11:36 PM.
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