Today I went back to the old racecourse in Richmond and gave another go at portable operation there but this time using my KT-8900D, this radio suffered from the intermod issue as well but nowhere near as bad as the VV-898, as for me to hear it I had to open the squelch (which is shown in the video I took).
I managed one QSO, and almost got another one too but there was some confusion on S20 as to who was calling who, no matter, one was better than none at all.
This has drawn me to the conclusion that I must now build a notch filter (or spend US$90 or so on one pre made which I'd rather avoid), as my intent is to block out pagers I can use the pager frequencies and the RTL-SDR to tweak it and suppress the pager transmissions so they don't cause intermod.
Looking online there are some designs for these, some use a coil of wire and capacitors and screened enclosures, of course what I need is something that can basically work to TX on 2 and 70 without any issue so I will look at that of course, however the ultimate aim is to stop the pager noise dead in its tracks.
I will obviously test the final design with the worst offending radio, the VV-898, in the field at the old racecourse.
73 de 2E0EIJ