At 08:01 PM 2/19/01 -0600, 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?
A gas tube may be a better idea than an MOV, given the fast rise time and
high peak current of lightning, even induced rather than direct hits. You
can buy an appropriate gas tube from the usual suspects. For protecting
Beverage terminating resistors, Steve Byan at Oak Ridge Radio suggests the
Siemens A81-C90X, which has a 90-volt firing voltage and a 20 kiloamp peak
current rating. Looks like it might be a good choice for this job too, if
it will fit physically.
73, Pete N4ZR
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