This is the Tram Model Diamond 40. Tram's deluxe 23 channel AM mobile radio. This radio was produced by Toshiba in Japan and was loaded with features, including Volume, Squelch, Mic Gain and Delta Tune controls, a switchable Noise Blanker, P.A. function and SWR metering.
This radio was a superb performer. Transmit audio was strong, and receiver selectivity was above average, and the noise blanker was excellent at suppressing ignition noise. This radio was functionally the same as the Browning SST, as Browning also contracted Toshiba to make their mobile radios. Curiously, the D40 omitted the modulation limiter, which was included in the Browning SST version. Undoubtedly, this allowed the D40 to have a higher level of modulation. But I wonder how they got that by the FCC.
I first ran across the D40 when Blue Bandit picked one up to run in his "tuna boat" mobile. His new Tram replaced a Midland 13-895 AM/SSB radio and I wondered why he would "downgrade" from an AM/SSB rig to an AM only radio. But the Tram was a much better receive performer, and had a little better transmit modulation with his Turner M+3 microphone. And Bandit didn't run SSB much from the mobile anyway, so that wasn't much of a loss for him.
I recently picked up a Diamond 40 from a forum member who was happy to donate a spare that he had. A little alignment and some cleaning and it's part of my vintage collection. On the scale of 1 to 10, I'd give this a 7. A solid performer.