Raymarine ST290 wind instrument

[DHHong Kong]

My Schionning Wilderness 56ft cat has a rotating mast and thus two Raymarine ST290 wind transducers mounted on poles, one each extending from either side of the davits at the stern. I have seen cats so equipped with a transfer switch to select the signal from the windward transducer to the one ST290 pod and analog instrument at the helm however the local Raymarine guys are scratching their heads at this foreign arrangement (not too many cats with rotating masts in Hong Kong).
Can anyone advise how to hook up the switch to select either transducer ?? Each has a four core cable running to the pod.
Grateful for your advice.
Cheers

Paul

[Beausoleil]

Simple - just use a 4PDT (4 Pole - Double Throw) switch as illustrated here. Similar to a DPDT (Double Pole - Double Throw), it will switch four leads simultaneously - in this case from the old windward sensor to the new one.

You could get really fancy and fab an electronic 4-pole relay which could sense when the bow goes thru the wind on a tack and switch automatically. It would probably have to sample the two direction leads from the transducer...

[DHHong Kong]

Thanks Cap'n John - The four pole switch should work and I think I will try it and see what happens. The Raymarine guys don't agree that the signal cables from the transducers can be switched and that each needs to talk to a dedicated pod. I am clearly out of my depth with this but, alternatively, I wonder if I can use the two pods and then switch the outputs he instrument.
I'll keep your fancy idea until later.........................
Congratulations on setting off on your cruise - I have 15 months to wait !!
Cheers
Paul

[mark_morwood]

The 4pdt switch will handle switching the signal wires for you. You may however run into problems with calibration of the transducers to the pods. I haven't used the ST290's but with the older Raymarine instruments I believe the calibration is managed in the head unit, so you won't be able to get both transducers calibrated.

You may want to go with your alternative idea of two pods, and switch the outputs from the pods.

Mark.