TMC GPR-90 GENERAL-COVERAGE RECEIVER.


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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.

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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.

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It is a bit dusty, but is otherwise clean.

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Top view.

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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.