Dick, if only that were true... Anything which changes the dielectric constant of the immediate antenna environment detunes the antenna, conductor or not. The power companies AVOID resonance in their transmission networks, and don't measure SWR, so they're concerned only with the mechanical effects of the added weight.
FM and TV Broadcasters go to much trouble and expense to maintain antenna heaters to deal with this issue. Some use ice detectors which evaluate precip and temp on the tower, to turn on the antenna heater automatically when conditions are favorable for ice formation. Otherwise, ice can form so fast the heaters can't keep up, and some broadcast stations have to shut down when SWR gets too high due to ice. 73, Paul, AE4KR ----- Original Message ----- From: ocwarren2000 To: [email protected] Sent: Tuesday, December 18, 2007 9:44 AM Subject: [Repeater-Builder] Re: Remote power monitoring --- In [email protected], Kris Kirby <[EMAIL PROTECTED]> wrote: > > On Sun, 16 Dec 2007, Eric Lemmon wrote: > > One question comes to mind: Is it really necessary that you know > > exactly what the forward/reverse power readings are, or the SWR, or > > are you concerned about whether the values have drifted outside a > > certain tolerance? I think that I would want to hear a voice > > notification that power is abnormally low, or the SWR is abnormally > > high, rather than the value. > > I always wondered how much a few inches of radial ice detuned at DB- 224. > ;) > Well, have you noticed the ice on power poles and how it gets caked on and yet causes no outages, particularly on the primary power towers going cross country? The only ice failures is the breakages as a result of the weight, because the ice is frozen distilled water and doesn't conduct. Surprised?? As such it shouldn't cause a change in SWR.. Check the Tillamook County, Oregon site and it shows telemetery chart of such things, of Mt. Hebo and Caper Mears installations, right on the Coast. Their power output will change, but not the SWR, and yet they are on the West Coast of the USA at the shore of the Pacific Ocean!! Best wishes, Dick, W7TIO > -- > Kris Kirby, KE4AHR <[EMAIL PROTECTED]> > But remember, with no superpowers comes no responsibility. > --rly >
