Thanks for the reply. I’ve just done what I should have thought of before – removed the antenna from the Rx. Noise drops drastically!
I’m just waiting for delivery of a ferrite Toroid which I was going to put in the supply to the PC hoping that might help, but if the noise is coming through the antenna then that probably won’t help.
I live on an ordinary housing estate with no industrial units nearby which could be generating the RFI,so unsure what to do next.