Hello all. Hope someone can shed some light for me on this, as I’m really puzzled in which would be best for mainly less RF interference and also less likelihood of getting struck by lightning.
Also, what routes should be taken for grounding of either option?
I appreciate any help and advice on this matter.
LeeWx
The PVC pipe would not be conductive, however it depending upon length could flex or whip around in the wind.
There’s a lot of comments been made in this and many other forums about lightning suppression for anemometers and the like up a pole… some say the suppression attracts strikes, others say that costs of getting sufficiently good suppression far outweighs the replacement cost of the equipment, and does not always work 100%.
I don’t have suppression on my stuff, and we’ve had lightning strike very close by here, where it not only tripped the breakers on the power pole 10 metres from the house, but fried a printer/fax, and a optomux, but did not upset any of my weather station gear.
YMMV.
PVC pipe needs to be kept to short length, like two feet or less. Anything more and it will flex like a wet noodle.
Not true… I used a 5 foot length (longest which would fit in my car)… what I did to reinforce it was use a smaller diameter PVC pipe inside of a larger one, glued it in, and capped both ends. We’ve had 45 mph gusts (since install) with no flexing of the pipe.
I’ve been toying with the idea of using a PVC mast. What diameters did you use?
Did you run your wire down the inside of the pipe?
Thanks guys! Appreciate the responses. Sounds like the PVC option outweighs the Antenna one.
The idea of putting another pipe inside the mast has been my thinking as well, as I've been thinking the lone PVC mast might be a little flimsy, as I live in an area that receives some occasional heavy duty winds(excess of 60mph).
How high a mast are you thinking of?
I -think- it was 1 1/4" and 3/4". The inner one fit pretty snug but I went ahead and siliconed it in just in case and capped on both ends.
I just ran the wire down the side and zip tied it every foot or so.
I’ve heard that PVC has some resistance to UV degradation. Does anyone know the UV tolerance of ABS? Painting would give added UV protection.
I would be a little worried that PVC would become brittle when very cold. I think ABS has a much lower working temperature range, but I’m not familiar with its strength and stiffness compared to PVC.
Steve
ABS has poor UV resistance. I think the black/grey PVC has UV stabilizers and is better than the white, but any of them are better than ABS.
I’d be using metal anyway :lol:
If your going to use PVC get a piece with SUNLIGHT RESISANT marked on it. I myself would use metal for greater stability.
If you must use PVC, use electrical grade conduit schedule 80 is possible to help with stability. Electrical grade conduit is sunglight resistant, and overall much better than regulat CPVC pipe (plumbing pipe)
We use it all the time at work, but while we’re not supporting weather equipment, PVC usually has a half decent life (~5 years) but nothing near what aluminum would have. The larger thicker PVC is suprisingly stable (one 10’ stick & 3" diameter) but if you really want to get your PVC mast “up there”, you’d want to use guy wires. Also, the ambient temperature has considerable effect on the pipe. In hotter climates, it will actually soften (1/2" PVC sitting outside can be fairly easy to bend without a heat gun) and at colder temperatures becomes more stiff, and brittle, though I havent managed to break a piece of conduit until you bend it about 50-70 degress or so.
Again though its been mentionned, if you must use PVC use electrical grade conduit but aluminum would make a better mast IMO…
MGCJerry -
The one that played with 40’ of 2 1/2" electrical PVC pipe today…
If it gets really hot where you are, PVC will just sort of wilt. Here in Arizona, you can’t make ham radio antenna supports out of it at all, unless you put a wood dowel or a metal pipe inside it.