Heathkit HM-10-A Tunnel Dipper

Over on the Antique Radio Forum, there’s a gathering of grid-dip oscillators.

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One of my contributions was this Heathkit HD-10-A Tunnel Dipper.

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It uses a tunnel diode as the active device in the oscillator.

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The oscillator level is metered by a circuit composed of a few transistors driving a D’Arsonval meter.

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The top originally contained a foam cushion for the coils, but that disintegrated long ago.

© Steve Byan 2011-2019