Did the DXE board have a conformal coating applied? If it did not (which
is poor design considering it is intended to operate outdoors), you can
get small cans of the stuff made by Techni-Spray. I've use the silicone
conformal coating on some boards I've made for outdoor use and it holds
up well IF you prep the board properly first (they make a cleaner for
this purpose). I found if you cheap out and skip the cleaning part the
coating doesn't adhere well and tends water can get under the coating
and damage the board.
Neither the conformal coating nor the "Blue Shower" cleaner that the
recommend are cheap, but they do work well. If you use the coating make
sure to mask off things like contact strips and contact surfaces. I
found that most common tape doesn't stay stuck when you apply the
conformal coating so you have to use the fancier tapes made for use in
the PC board manufacturing process (the kapton tapes seem to work OK).
-Bill
> I would avoid any attempts to do relay switching by supplying voltage
down
> a
> coax cable but rather use two coax runs. The relay, blocking cap,
diode
> and
> associated circuit in my case with two DXE boxes have deteriorate
within
> less than a year to be useless, mostly due to electrolysis and
zillions of
> ants attracted apparantly by the voltage or relay coil vibration when
> pulled
> in. (Yes I covered all the edges with
> silicon sealant) DXE refuses to send me a print to repair the board
[snip]
> Herb, KV4FZ
_______________________________________________
UR RST IS ... ... ..9 QSB QSB - hw? BK
|