Re: Spyverter R2 with USRP B210 #shortwave


jdow
 

For what it is worth DC->60 MHz is shifted to BOTH 120-180 MHz and 120-60 MHz. It's called imaging. 1MHs appears at both 121 MHz and 119 MHz on the output of a mixer. Filtering on the mixer output can remove the image if it becomes bothersome. Done wrong it will also remove the spectrum near DC, probably up to over 2MHz with reasonable circuit element Qs. This is clearly shown in the second picture. The first picture may be not showing the broadcast band due to filters and possibly a very small antenna.

{^_^}

On 20190217 09:10:44, erik@cryptmail.net wrote:
Hi,
I purchased a Spyverter R2, and connected it to my USRP B210.
I note from Airspy, "that moves the entire HF spectrum to the VHF band between 120 MHz and 180 MHz".
I am connected to a 30m 'long-wire', via a balun to FM bandstop, and then to the usrp.
Now, I'm not expecting any signals <120MHz... but I have LOTS of stations to listen to, and clearly right from the start of the band, you need only expand the screen to see them individually:
Then, where I'm expecting signals from 120MHz through 160MHz, I find discernible stations below 100MHz:
Not what I was expecting at all.
Furthermore, if DC to 60MHz, is shifted to 120 through 180MHz, then do I assume 121.350MHz should equal 1350kHz? and 140MHz should equal 20MHz in reality? *Nothing* is aligned with the global list of stations I have.
Spyverter is powered from USB port on laptop.
Would anybody be so kind as to offer some thoughts here?
Thanks and regards,
Erik.

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