[amsat-bb] Another first: rotor problems

Hans BX2ABT hans.bx2abt at msa.hinet.net
Mon Jun 24 13:34:57 UTC 2019

There is a first for everything. So today for the first time in my 10 
years as an amateur radio operator I experienced that my KR-400 rotator 
(partially) stopped working. It has not been in use for 10 years, only 
the last 8 months and the motor was cleaned and greased before the 
install. Before I start dismantling everything I would like to see if 
any of you have any good advice.

The problem --- it will turn right, not left.

What I measured --- between terminals 5 and 6 (right turn) I measured 31 
Volts, which is normal. Between 4 and 6 (left turn) only 21 Volts. Rotor 
not connected to the controlling box when measuring.

My thoughts --- must be in the controlling box. However, there is simply 
nothing there in the circuit that I think could act up. From the 
transformer one terminal carrying 29 Volts goes to two switches. The 
other terminal is neutral. There is the light bulb between the two 
terminals and a 70 uF/50V capacitor between the two switches.

I could be entirely wrong, so spill any info and/or tips that you can 
give me, here. Cheers,



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