First test of Heathkit RF-1 after changing some components, mainly electrolytics but also the oscillator tube socket. Had been replaced with a skirted type, totally unsuitable because it could only be mounted on top of the chassis plate, this made it too high so that the ECC81 / 12AT7 tube was pressing against the side of the case so that the screw holes for the case won't line up. The low-profile plastic socket I put in is just the job, the case now fits perfectly but I had to basically rewire the oscillator stage. Here is a simple test if everything works by using a small battery AM radio to pick up the signal from the modulator tube. The audible tone is the internal 400 Hz oscillator, being transmitted to the radio.

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