What is this?

by Adam Farson, VA7OJ/AB4OJ

Well might you ask! Fig. 1 illustrates the rotary coil turret inside the RF front-end compartment of a Radiometer Model AFM2 Modulation Meter. The coils and trimmers are adjusted to calibrate the tuning dial; there is one pair per range.  Turning the bandswitch rotates the turret , switching in the LO tank corresponding to the selected frequency range. The air-variable capacitor to the right of the turret is the instrument's main tuning capacitor.

Verily a thing of beauty.

Fig. 1: The RF tuner of the Radiometer AFM2 modulation meter.
The RF tuner of the Radiometer AFM2 modulation meter. Image: VA7OJ. 
Copyright © 2011 A. Farson VA7OJ/AB4OJ, including images. Last updated: 09/25/2019

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