On 3/23/2025 5:30 PM, Jorge Diez (CX6VM-CW5W) wrote:
Manual says to use no less than 0.75 mm2 wires. Don’t talk about the length
In the Yaesu rotators I use, big copper is needed only to run the motor;
position is sensed by the position of a potentiometer (variable
resistor) physically linked to the rotating side, so small copper works
just fine.
I'm looking at the user manual for the PST-61 and two other models, and
it does the same thing. Wires 1 and 2 drive the 12VDC motor, wires 3, 4,
and 5 are connected to the potentiometer. They specify 1 sq mm for the
motor, 0.5 sq mm for the other three. Those numbers seem to be based on
current-carrying capacity, not allowable IR drop.
Obviously incomplete information if you're buying cable for a long run.
A question for you, Jorge. How long is your rotator cable? If it's
short, you only need to double up the wires on the motor, so that's one
pair for each wire. You've got two pairs (4 wires) left for the pot, and
only need three.
A trick I've used when trying to fit stranded wire into a contact that
is too small for it is to simply remove enough strands right at the
connector to make it fit. For you doubling up conductors, strip them a
bit long, cut one shorter than the other, solder it to the longer one,
and solder that longer one to the connector, using short pieces of heat
shrink to insulate the bare wires as needed.
73, Jim K9YC
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