Calibrating out a non-linear frequency response from an IF tap

[M0SJW]

I have a few radios with IF taps fitted - FT-857, FT-847 etc. I run external radio with various SDRs. I really like the setup.

Unfortunatly the panoramic output isn't linear around the centre. I'm not sure if this is experienced by many, but I see it it with multiple transceivers and every SDR I've tried with them.

I have scaled the Spectrum display in the screenshot below to accentuate the symptom.



The setup is obviously still usable but it causes the Spectrum and waterfall to be cluttered. Is there any way of calibrating out this frequency response in software please? Similar to how a VNA might be calibrated to null out the test fixture?

I'm currently using a RSP1 (clone?) but also have a limeSDR mini and RTL-SDR v3.

73,

Sam M0SJW

[kk4x]

i too have that issue, but using a JRC JST 245 with the I.F. of 70.455, how do i get SDR console to let me configure the I.F> frequency to be used with a Nooleec smart. appreciate all inputs. i am excited to get this to work with SDRConsole v3.2,73, Ed
kk4x

[Alezis]

FT1000d display similar issue too.