Gentlemen:
I understand that this info may be widely available but I don't
think it hurts to repost it from time to time for newbies. It
is at least as useful as the overdone thread on "True North"!
I just got off the phone with Gary Kunkee, rotator repair man
at Telex-HyGain. He gave me an education on the Ham-M,II,III,IV,V
series rotators.
Disclaimer: I only have a rudementary knowledge of these rotators
and can't verify or guarantee the accuracy of the following. It is
based on what I THINK I heard and understood!
The basic hardware of the rotator hasn't changed much with the
notable exception of a change from a zinc gear to steel and an
internal wiring change (different ordered use of the 8 terminals).
Most all parts are interchangeable to this day.
Identification:
There were 5 series of Ham M until 1972 whereupon the name changed
over time to Ham II, III, IV and V. Look for a four digit number
on the Brake Casting (one with terminal strip on it). Some units
may not have this number (I think). The first digit may be 1 through
5 indicating Series 1 through 5 of the Ham-M. The Ham II, etc. should
be stamped as such (Roman Numeral number). I think the Ham V is
actually a Ham IV with a fancier control box. The next three digits
indicate the week (2 digits) and year of manufacture.
Miscellaneous:
Grease is used modestly, not "packed" as may be commonly thought.
Currently they use a product called Nyogel 727F but a low temperature
white lithium grease is usable instead. Nye Lubricants, New Bedford,
MA, Ph: (508)996-6721.
The main control box transformer is either a 120 or a 240 VAC
input winding. It puts out typically 30VAC under load. But 26 to
28VAC is okay too. He usually measures 1.5A up to 2.0A current draw.
If more than 2 amps is drawn he usually changes the motor.
The Series One and Two can be internally rewired to the later
standard and be used with the newer control boxes. One give
away (internally) on these two series is a wire between the
pot and to limit switches. Later models do not have this wire.
Measurements made on the various terminal combinations with
certain results can determine which of the two wiring standards
you have.
Typical Measurements on Rotator Terminal Strip:
Ham-M Series 1 & 2
Between terminals:
1 & 2 0.75 Ohms Brake Solenoid
1 & 3 2.5 Ohms Motor Winding
1 & 4 2.5 Ohms Motor Winding
1 & 5 2.5 Ohms Motor Winding
1 & 6 2.5 Ohms Motor Winding
3 & 4 5.0 Ohms Whole Motor
3 & 5 Short
4 & 6 Short
3 & 7 500 Ohms Position Feedback Pot.- end to end
3 & 8 0 to 500 Ohms Pot.- One end to wiper arm
8 & 7 0 to 500 Ohms Pot.- Other end to wiper arm
Wiper is No. 8 on this series
Ham-M Series 3 to 5, Ham II, III, IV, V
Between terminals:
1 & 2 0.75 Ohms Brake Solenoid
1 & 8 2.5 Ohms Motor Winding
1 & 4 2.5 Ohms Motor Winding
1 & 5 2.5 Ohms Motor Winding
1 & 6 2.5 Ohms Motor Winding
8 & 4 5.0 Ohms Whole Motor
8 & 5 Short
4 & 6 Short
3 & 7 500 Ohms Position Feedback Pot.- end to end
3 & 1 0 to 500 Ohms Pot. One end to wiper arm
1 & 7 0 to 500 Ohms Pot. Other end to wiper arm
I hope this useful to someone. It at least gave me a reason
to enter it into my computer (hopefully for posterity).
Aloha, 73
Kimo Chun KH7U
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