[TowerTalk] Rotator capacitor value question

Richard (Rick) Karlquist richard at karlquist.com
Mon Jul 9 15:35:21 PDT 2012


I tested an HD-73 rotator yesterday using a Ham-M control
box.  I put the controller on a variac to reduce the voltage
from 24VAC to 20VAC.  The HD-73 hums and turns VERY slowly.
The brake does release but in a fairly lazy way.

Before sending the HD-73 off to Norm's rotor service,
I am wondering if this was a fair test considering that
the Ham-M has a 130 uF capacitor (that is at least 40
years old) and the HD-73 control box specifies a 155-193 uF
capacitor.  How critical is the capacitor for this go
no-go test?  The Ham-M control box works perfectly on a
Ham-M and two Ham-IV's that I have used.  Cranking up
the variac to get extra voltage on the HD-73 didn't help.
I have purchased an HD-73 control box, but it hasn't
shipping yet.

The reason for use the HD-73 is that it is the only rotor
that will fit the small tower I am trying to use.  This
is because it has a removable mast clamp that allows me
to insert it into the tower sideways.

Rick
N6RK


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