Re: Need K3 dB Measurements on new 160M Antenna
Posted by
David Cutter on
Aug 30, 2010; 6:25am
URL: http://elecraft.85.s1.nabble.com/Need-K3-dB-Measurements-on-new-160M-Antenna-tp5468244p5476964.html
It did cross my mind that if you just want to verify, say the elevation
angle and intensity of the main lobe, you could launch a balloon some
wavelengths away carrying a field strength indicator. With everything else
non-metal, the meter could send data via fibre to the ground and make a
measurement at every metre/foot. Then move the balloon to another spot on
your plan and repeat. Repeat for each antenna. As long as it doesn't rain,
I would think that would give consistant results and it would take into
account the ground around the station.
David
G3UNA
>
>
> Geoff,
>
> To do good antenna testing you need an anechoic chamber or better
> operate in deep space. My primary interest in radio are the microwave
> bands. I do set up antenna ranges for 10 GHz (3cm), In doing so, I find
> the wind blowing tree leaves will have a non trivial affect on the
> observed signal even though the trees are "out of the way." I find that
> I need to place the reference antenna and the antenna under test in
> exactly the same place (x y and z position) to get true A/B comparisons.
> This is demonstrated by taking two known antenna and see how repeatable
> the observations can be.
>
> Scaling these realizations up to HF antenna causes me to throw up my
> hands. Yes we do the best we can testing antenna, but we have to be
> realistic about the data we collect. When anyone makes claims about
> their antenna I listen carefully for the details on how the antenna was
> tested.
>
> Maybe we should ask ARRL to fund a synchronous satellite over the US
> with a beacon on each of the HF bands so that we can point our antenna
> up and make more valid comparisons.
>
> Don, N0YE
>
>
______________________________________________________________
Elecraft mailing list
Home:
http://mailman.qth.net/mailman/listinfo/elecraftHelp:
http://mailman.qth.net/mmfaq.htmPost: mailto:
[hidden email]
This list hosted by:
http://www.qsl.netPlease help support this email list:
http://www.qsl.net/donate.html