[G0HZU_JMR]

If it helps I dug out my old Trio/Kenwood TR9130 2m multimode and had a play with it. Back in the mid 1980s the TR9130 was one of the radios classed as being a bit deaf and I did a few quick tests on mine. I've never tried to align it as I've never actually used this radio in transmit (no microphone came with it) and it shows a noise figure of about 8.5dB when I test it with the noise source with the TR9130 set to SSB mode.

The sensitivity specifications for this radio are potentially confusing because of the 6dB difference between uV EMF and uV PD for a receiver with a 50 ohm input. However, I think the Japanese radios are spec'd in the glossy brochures using uV PD but in the service literature the alignment checks are done in dBuV EMF.

So this is potentially confusing! The alignment check in the service manual says in SSB mode the sensitivity for a European (144-146MHz) TR9130 is -8dBuV for 10dB S/N. So this is 0.4uV EMF or 0.2uV PD. This is also in S/N rather than S+N/N.

This roughly translates to a noise figure of about 9.2dB and presumably this will be at the 2m band edges where the sensitivity might be slightly worse.

So my radio is probably quite typical if it measures the noise figure to be about 8.5dB near the middle of the UK 2m band. The spec for a stock Yaesu FT290R in SSB mode is 0.5uV for 20dB S/N and this means the noise figure must be somewhere around 7.2dB.

So the 290R is probably only slightly better than the TR9130 in terms of sensitivity. If we assume the Mutek version can be optimised to get a 2.2dB noise figure then that's up to about a 5dB improvement max. However, once you factor in a ballpark antenna noise temperature at 145MHz of 600K (under fairly favourable conditions for galactic noise etc) and maybe allow about 1.5dB feeder loss the difference between the radios will be reduced to maybe 3dB at times. On a noisy band there will be very little difference at all.

Back in the 1980s when I was active on 2m SSB, there were some very serious operators chasing contests and awards and for them every dB improvement in S/N really mattered. However, in 2018 a fairly casual operator on the 2m SSB band probably won't get to notice/appreciate the difference because the band is noisier today and a difference in S/N ratio of maybe 2 or 3dB isn't that significant unless you are desperately trying to make contacts right down in the noise to grab another locator square or county/country or to get a few more points in a contest.