I have done this with My UHFSDR to push its UHF operation up to 1Ghz (limited by Mixers) and i thought i would do that same test with the LimeSDR
i has asked some time ago what kind of signal is sent to the mixers in the Limesdr and was assured that it was Square wave …—… that was important to me —
UHFSDR also uses a square wave Lo.
UHFSDR running Quisk (Odroid-X2/Ubuntu16.04-32bit)
LimeSDR runnung GQRX (Odroid-C2/Ubuntu16.04-64bit)
Jim Veatch sent me these Band pass filter for 2M band and has a 3db point at 180Mhz and drops fast from there …
The idea was to test the possibility of operating with reduced performance above the 3.8Ghz Lime limit.
What is 54.166 X3? 162.498
What is 3.456Ghz X3 ?
The Large spike next to the weather transmitter is the leaking Lo of my UHFSDR.
Unknown yet is max frequency range of LNA and the Mixers … TIA and the PGA (what ever that last amp’s called – i forget) does not matter since they are IF range.
No, i don’t believe that the I/Q transformers can go to 10Ghz with out alot of attenuation … there would need to be some modifications …
Also in the video the weather transmitter is on the left of center – i think it should have been on the right side but i need to recheck what i did …