23 July 2024

630 meter band

Remote MF antenna variometer

In the video I show you the tests on the renewed 630m band variometer. I’ve changed the old motor with another with gearbox ratio of 1:30 so to get a better resolution during the antenna tuning. It’s possible a continuous variation of the speed, too.

The pot is used to change the resistance to a simple 555 circuit so to change the speed of an astable configuration circuit. The squared wave goes to a little and cheap driver for bipolar stepper motor (indeed, my motor is unipolar… but is possible to use as bipolar).

In the next days the variometer will go near the base of the new antenna that at the moment is lying on the roof.