Thursday, November 24, 2011

Central Heating Aerial

Dear readers, there was not much going on here lately, sorry about that!
Today, some weird incident triggered another thought in me.... and here it comes:

Returning home, I felt an unfamiliar chill in my house... That's no good, I thought, and checked the central heating system, which indeed was dead. Quick check and the culprit was found. The expansion vessel (expansievat, Ausdehnungsgefäss, vase d'expansion, whatever you wanna call it) leaked. The local hardware store was still open, hence I hurried up to get a replacement of similar size.
Just €22.- will get you one with a 17l capacity.
Speaking of capacity, that came to my mind on my way back home. What about using the defective one as top-capacity for a short vertical? The roundish things got a nice thread which would easily fit Cu pipes and respective fittings.
The vessel itself is made from steal (Fe) most likely. OK, that's somewhat on the heavy end, electrically however, not that inferior to Al, which is used most.
The plan is to build a short tapered vertical from Cu-pipes with an expansion vessel on top.
I figure, one may also consider a short loaded dipole.
Possibly, just 2 of such vessels could make a broadband dipole for VHF.... one could also think of a broadband vertical for VHF, using just one vessel on a ground-plane.

There may just be one down-side, your neighbors will think you're completely mental, putting the expansion vessel of your heating system 5m above your roof ;-)

Happy experimenting.


  1. You really got some crazy ideas :-)
    But that's what amateurradio is all about.
    73, Bas

  2. Thanks Bas, it is all about having some fun! And why should I through away a perfectly good metal thingy, just because the rubber membrane got bad ;-)