Yaesu G-450A rotor wiring

[W7MJM]

Just spoke with HRO.  Based on that conversation, I plan to connect the AVG 18 wires to pins 4 and 6, and to double up on the AWG 22 wires to pin 5, since those three connect to windings on the motor and therefore carry more current. The other three pins connect to the sensor circuitry for indicating the beam heading, for which AWG 22 should be adequate. If anyone objects, speak now! 

I just purchased a Yaesu G-450A rotor from HRO. They also sold me 75 feet of 8-conductor light-duty rotor cable (2 wires are AWG 18 and 6 wires are AWG 22) to use with it.

The Yaesu manual recommends 6-wire conductor with a minimum of AWG 20 for all 6 wires on a less than 125-foot run. I assume HRO sold me the light-duty 8-wire since that's the one they carry and it can support the widest range of light-to-medium-duty rotors.

I also assume that only two of the wires need to be at least AWG 20, the ones that supply power to the motor, and that the others can be AWG 22, but looking at the schematic, I'm getting a little bit confused as to which ones. Either my brain or my bifocals are to blame.  

Can someone out there tell me; to which pins should I connect the AWG 18 wires? And will the AWG 22 wires be adequate for the lower-amperage control functions?

Thanks and 73,
Martin, W7MJM

[K2DC]

Martin,

   If you're using heavier wires, 4, 5 and 6 should all get the heavier stuff, as they all can carry motor current (4 and 5 to turn left, and 5 and 6 to turn right).  By the way, the G-450XL Manual that I'm looking at says 24AWG for short cable runs, 22AWG for cable runs over 130'.

73,

Don, K2DC

[W7MJM]

Thanks Don. Your comment supports the approach I'll be taking. I'll use the two available #18 AWG wires for two of the three heavier-current pins (4, 5 and 6) and double up a couple of the #22 AWG wires for the third. I'll connect the remaining lower-current pins (1, 2 and 3) to individual #22 AWG wires.

As for the variance in control cable specifications, the G-450A manual may specify greater gauge (#20 AWG) control cable wire than indicated in your G-450XL manual because the G-450A manual also covers the G-650A and G-1000A, which appear to be heavier duty rotors than the G-450A.

In any case, if Yaesu is specifying #20 AWG wire for all the pins, including the high-current pins that supply power to the motor windings, then #22 AWG will undoubtedly be fine for the low-current indicator pins, and #18 AWG or double wired #22 AWG will provide an additional margin of safety on the high-current pins, especially on the light-duty G-450A.

73, Martin W7MJM