In a message dated 7/13/2004 10:00:23 AM Eastern Standard Time,
towertalk-request@contesting.com writes:
John now has nearly a dozen prop-pitch motor/selsyn cables laying on the
ground without any indication (so to speak) of what the connections are at
the tower. It would be really great if someone could suggest a method -
such as an ohmmeter or DC measurement - that would allow him to figure out
the connections without having to laboriously climb up and down the towers a
million times.
I've volunteered to help figure this out for John, but maybe this would be
of help to others with "mystery wiring", too. Such nfo might be of use for
troubleshooting. Suggestions?
73, Ward N0AX
=====================
Ward,
Sounds like a great treasure with "dozens" of prop pitch motors. They are my
favorite rotator, tough and reliable. Checking out the windings from the
ground may be difficult with out having some idea of the circuit used. The
motors are simple, a common pole, and CCW and CW pole. Look for the common
polarity indicators such as RED, WHT or BLK leads, also the heaviest conductors
will
likely be the motor feeds.
Also there is likely to be limit switch circuitry which will have its own
common, or be connected to the motor common and then two leads for CCW and CW
limit signal. That is a minimum of 5 wires.
Using the heaviest wires and with a 28volt power source it is a touch and try
proceedure - note the polarity and direction of rotation.
If the Selsyn transmitter wires are included that is another minimum of 4
wires if one of the S windings have been connected to one of the R windings.
Sorting out which is which remotely may not be possible. But one climb and
inspection will likely set the pattern which could be used for all other
indicators.
Regards,
Norman W4QN
http://www.cubex.com/
_______________________________________________
See: http://www.mscomputer.com for "Self Supporting Towers", "Wireless Weather
Stations", and lot's more. Call Toll Free, 1-800-333-9041 with any questions
and ask for Sherman, W2FLA.
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