Larry,
I can only speak to question 1. It sounds like your reed switch is being
damaged by arcing when there is a near lightning strike. That's not
unusual given the length of rotor cable and the relatively low breakdown
voltage of reed switches (just a few hundred volts). That being the case,
you should get excellent protection by paralleling a suitable varistor
(MOV) across your switch(s). You want a part whose standoff voltage is
higher than the normal open circuit voltage found across the switch but
whose clamp voltage is lower than the breakdown voltage of the switch.
A suitable part could be Digikey P7240-ND (Panasonic ERZ-V05D101)
or Digikey P7252-ND (Panasonic ERZ-V10D101) which is physically a
little larger but can disipate much more energy. These selections are
made on the assumption that your switch open circuit voltage is well
below 100 volts.
73,
Mike, WA4BPJ
On 16 Feb 2001, at 22:36, Larry Alkoff wrote:
> My M2 Orion rotator reed switch has failed for the second time in 6 months
> during a lightning storm that did no other damage.
>
> Each failure requires climbing to the top of 120 foot tower, dismounting
> rotator
> to replace reed switch, then re-installing rotator.
>
> This is really getting old, especially since it likes to happen the day
> before a major contest! The good news is I have Africa covered <g>
>
> I have two questions.
>
> 1. Does anyone have any thoughts on "protecting" the reed switch?
> Can it be zapped back to life?
> Note: The rotator power and control cables are protected
> by Polyphaser devices both at the bottom of the tower and the
> shack.
>
> 2. What other make of rotator could replace the Orion to turn a stacked
> C31XR and Cushcraft XM-204?
>
> 73 Larry Alkoff N2LA
>
>
>
>
> Larry Alkoff N2LA - Austin TX
>
>
>
>
>
> Larry Alkoff N2LA - Austin TX
>
>
>
> --
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