Topband: Relays and heating

Uwe Koenneker, DL8OBF dl8obf at
Mon Mar 27 04:33:45 EST 2006


W2PM wrote:
   Are these hermetically sealed or only enclosed? Ive noticed that without

   hermetic (airtight, vacumn) sealing the inside of the "sealed" 
   housing  will 
   still get quite wet because of the temperature changes in the 

I would like to add on the topic of "condensed water": I have mounted the
Relays of my Vertical on a sheet of aluminium. That metal is heated by some
resistors, which I operate on 12V. There are foil resistors, which are sold
locally at "Conrad"". Typically these are used to heat car-mirrors and they
sell for a few Euros. They come with some kind of "glue". I guess you get
these resistors in other countries as well.

To limit my electricity costs:
- I use another normal resistor directly under a bimetal switch
- And I have a clock, witch switches mains off during the day, so I heat
only at dust, dawn and in the night.

Just to add a few ideas,
Vy 73
    Uwe, DL8OBF 

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