TMC GPR-90 GENERAL-COVERAGE RECEIVER.

(Click for full-size picture)	This is the fameous TMC GPR-90 general coverage receiver. The frequency range is 540 kHz to 31 MHz. There is a 455 kHz IF output on the back for an SSB adaptor, like the GSB-1 or the CV-591A. I am told that these were designed by a bunch of engineers that came from Hammarlund. The similarity to the SP-600 is evident. In some ways, the construction of these receivers is different from most TMC construction. It is not built quite as solidly as most TMC equipment.
(Click for full-size picture)	I have checked out the receiver and it works well in all modes. The alignment seems quite close to me. It could probably use some touch-up. By use of the calibrator and the band-spread control, I got the dial to read quite close, although I couldn't get it to read properly at both the high and low ends of the band at the same time. This smells of an alignment issue. I didn't try to realign it myself.
(Click for full-size picture)	It is a bit dusty, but is otherwise clean.
(Click for full-size picture)	Top view.
(Click for full-size picture)	Charles replaced the 5U4 rectifier by two silicon diodes and a 125-ohm dropping resistor. This is probably a good idea. It knocks out 15 watts of filament power.