antenna question

[adkad]

Hi: I have a dedicated airband antenna up thirty feet attached to a pole attached to an arboreteum. I get most frequencies within 50 miles but not all. I could attach the pole to a tree and get between 10-20 feet higher but would have to run the coax over the roof and add another 20 feet of cable. Would I gain more with the height or loose more with in increased coax? Thanks for any comments. Adkad

 

[richrowl]

Antenna height

Seems like years ago I read that it would be necessary to double the height of the antenna
in order to have a noticeable difference.

 

[cnmsales]

I would say it probably depends on the type of cable you are currently using and if not sufficient for the added height would you be willing to upgrade you cabling. Im sure someone with better knowledge will be able to give you a better answer.

 

[N_Jay]

Seems like years ago I read that it would be necessary to double the height of the antenna
in order to have a noticeable difference.

Rule of thumb, doubling the height (HAAT) will give you approximately 6 dB, which is 4 time the signal and IS a barely noticeable difference on most signals.

 

[cnmsales]

Right but on top of that he would also be doubling the cable length which would cut the 6bd back some. So on top of the fact that he would only be gaining 6db and that isnt very much he would loose even more with the extra cable.

 

[LarrySC]

Signals from overhead, like aircraft, dont need an antenna very high. If its tower signals you need more of, I dont think you could measure any increase with 20' more. I'd go with 30'. Good Luck.

 

[kb2vxa]

Yup, there comes the point of diminishing returns. Then again unless it's some pretty crappy cable another 20' makes a negligible difference. Might I suggest the proper way to go would be to raise the antenna and change the coax to one with "the best bang for the buck" in one uninterrupted length? If you do your homework and find the least loss within your price affordability range you have nothing to lose and everything to gain, pardon the pun.

Never mind the nit pickers, let them have thier way. Remember, picking nits keeps you free from lice.

 

[adkad]

Thanks all. I think I will see about the possibity of increasing by 30ft and go with the best cable. It is a question of picking up more of the ground stations. Interesting though, the antenna though airband does great general scanning as well. I get more on it than anything I've used before. Thanks again, Adkad