There has been a debate amoungst some of our club operators, concerning stated "antenna height." Our antennas are all mounted at a nominal 125' ASL (Above sea level) on a relatively flat and level platform. A couple of Yagi's are about 10-12 feet above that level, and a few verticals (up to 43' tall) are also mounted at approximately the same platform level, with a few feet (approximately 10') elevation for normal mounting . Some operators want to say the antennas are MoUNTED at the 135' level, which IS accurate. Others want to say (the vertical) antennas are 168' above sea level.
What would YOU consider the most honest answer?
I would think that the altitude of the location of the antenna farm is what would be accurate, as that shouldn't change...barring a massive earthquake.
Details would be the size of the vertical antenna, tower height, etc. Those can vary.
Height above sea level is largely irrelevant and has little, if anything, to do with take-off angle. My question to them would be why choose a measure of elevation like sea level that is meaningless.
For VHF and UHF, the AMSL height might have some bearing because a lot of the contacts are "line of sight". But, on HF, the height above ground level generally has the most effect.
If it's the QM radio club, I'd just say how high the antennas are above the main deck and tell people that to turn the antennas on them I have to turn the ship around.
See how many can figure out you're kidding.
A government which robs Peter to pay Paul can always depend on the support of Paul.
-- George Bernard Shaw
The word from the ARRL bible of many years ago, when there was every day propagation between Europe and the US was 52 feet above ground, the height of the land above sea level is immaterial. Think about it !
Height of an antenna is the height of the feedpoint above the earth underneath it.
Not exactly brain surgery.
"Clear intent is the best predictor of experience"
If ASL is the measurment, then my antennas are almost 6K feet!!!
I like HAAT myself. My antennas are on a 50 ft tower, but the ground directly below it slopes away so fast that you couldn't play soccer. My antennas are at 110ft HAAT. I think that gives a decent description.
But my tower is 50 ft. That is the official height.
"Life is just like ridin' broncs, its a battle". Chris ledoux
Long live Steamboat
Exactly. Height above sea level (ASL) means little unless your support structure is at the shore.
Originally Posted by KC7YRA
Chicago is about 600 feet ASL. If you lived there and your antennas were 125 feet ASL, they'd actually be 475 feet under ground level! Much better to use HAAT.
42 years in Amateur Radio
In that case my antennas are at 1400+ feet, sure doesn't seem to help much!