TEST: different units show SNR and USB noise 480MHz

[hamradionl]

I monitor the VHF and UHF only.
Some test i did today all receivers connected to same antenna and monitor same frequency.
And also showing the USB noise on 480MHz. In coming days i post screens from USB noise on 960MHz
RTLSDR-V3
Airspy-mini
Adalm-pluto
RSP1A
NoelecSmartV4

 

[hamradionl]

USB cables high-quality and use extra ferrite clamps.
First topic show the SNR levels and USB noise on 480 MHz
Some units the SNR are 2 - 3 dBm higher.
! - Also notice the very high USB noise level coming from the Airspy-mini on 480MHz - !
Using RSP1A in VHF and UHF range the SNR and AGC is acting different as show in other units.

Some other screens show USB noise level on 960 MHz
Screen 1
NoelecSmart-V4 + RTLSDR-V3
Screen 2
AIRSPY-mini + NoelecSmart-V4
Screen 3
AIRSPY-mini + RTLSDR-V3

! - Also notice the very high USB noise level coming from the Airspy-mini on 960MHz - !

 

[hamradionl]

Some other screens show USB noise level on 960 MHz
Screen 4
AIRSPY-mini + RSP1A
Screen 5
AIRSPY-mini + PLUTO SDR

In this fallow up the screens show different noise levels between the units. Some more expensive units show very high noice and some lower priced units show lower noice level.
When you search or buy a unit this information be helpful to find your best choice.

 

[iMONITOR]

Found this:

High Speed USB Noise - Signal Identification Wiki

High Speed USB 2.0 clock noise. Shows up at multiples of 480 MHz.

www.sigidwiki.com