Just looking for anyones thought on how high a cb base antenna really needs to be or is height really might?I talked to a tech at maco back when they were maco and was told 40 ft is plenty high enough for a antenna, so what do you all think, Thanks

http://signalengineering.com/ultimat...radiation.html

Explains about height and how it will affect your signal.

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MoJo
www.mojoenterprises.us

Albino128
my pine trees are about 65 to 70 feet in the air.My antron99 sits only 5 to 7 ft lower
everybody in my neiborhood says I bleed on them,whats that telling you (higher is better).I use to live up in the coner of the buck 10 my, brothers maco was atleast 100 ft off the ground ,just alone we talked to cleveland from andover ohio barefoot

i would at least try to get into the second wavelength, which is like 36' high. any antenna at 40' will usually get the job done.

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There are sort of two parts to that question. One part is that the height above ground affects the amount of reactance between the antenna and ground. That means that tuning the antenna can change if raised or lowered an appreciable amount.
Another part is that height affects the radiation pattern. The horizon gets further away the higher the antenna is, so it can 'see' further in a straight line, before any 'skip', sort of. Not too important at HF really, but it is important at VHF/UHF. So, the higher the better to some ridiculous point.
So, how low can an antenna be? The lowest for most vertical or groundplane, or non-horizontal and directional antennas (beams) is -at- ground level, does no good at all below ground level. Those directional antennas have sort of a catch, cuz they could be 'vertical arrays' such as broadcast stations have. Ground level and directional, sort of harder to turn though.
Best all around height for a typical vertical groundplane type thingy is as high as you can get it.
The only kind of interference that height can 'cure' is 'over-load', since it's further away from the affected device(s). Won't 'cure' spurious or harmonic type interference since antennas don't 'produce' any signal, they just radiate what's fed to them. They can attenuate or increase the signal, just can't make any of their own.
- 'Doc

it depends on your local topography / ground conductivity and where you want to talk to,
in my area i had the best results from antennas mounted in a field at 73ft or about 2 wavelengths to the feedpoint, if i could have gone higher i would have,

some antennas work well even when mounted low and some don't,

for local talk the higher you get the antenna above its surroundings and ground the further you can talk in my experience,

for talkin skip the best height is the height that gives the takeoff angle that allows you to skip to where you want to talk,
the best height constantly changes with the conditions of the ionosphere.

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its all about the learning

"the best height constantly changes with the conditions of the ionosphere."

in direct correlation to the height and ionization levels of the F1 & F2 layers
which can range typically anywhere from 90 - 250 miles above the earth.

See: The Ionosphere, F1 & F2.

http://www.firecommunications.com/propflash.htm

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292 Radio Shop / FireCommunications Network
The Technicians Exchange    ASH    Ref

Basically Higher is Better
But
There comes a point we can not keep it up high safely
or antenna height restrictions in your area come into play

Mine are at 52 or 54 ft at the base of my 11 meter antenna
and it works great

Location has a lot to do with it

get your antenna high enough at least so it gets a clear shot to transmit
is best to get it a full wave length or higher

good easy to understand post jack.

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its all about the learning

Hight is good for the groundwave, after 1 wavelength above ground the radiation pattern will be good for DX, depending your surroundings, houses etc wich might be higher.

My vertical is 11 meters above ground, flat terrain, and working the world on 15 - 10 meters with it.

It's an Imax 2000 with ground plane, added ground plane wires for 15 and 12.

For the groundwave, gaining 1 S point needs an doubling of your antenna height.

For DX, selext an vertical that has the lowest angle of radiation.

Worked the USA 100 watts with the imax on 10 meters yesterday

Cor