RadioBanter - View Single Post - Need help with antenna decision/ 70' mount

October 15th 04, 12:02 AM

(Mike) wrote in message . com...
I currently am using an Alpha Delta DX-Ultra mounted at 70' sloping to
about 15 feet above ground. This antenna in this configuration is
noisy. I am considering an Alpha Delta DX-SWL or maybe a vertical
antenna. I know the height is a bit much, but the higher it goes the
more antenna I can get on my property. I even used this antenna in an
inverted "V" configuration with much noise. So if you had an area you
could easily mount an antenna 70' in the air what would you go with
that would not be noisy. I like to have this antenna work on the
tropical bands.
This antenna is suspended from a tree using a pulley system.
Thanks to all
If I find a solution the DX-Ultra will be sold...anyone interested?

Noisy? Where/what is the noise source? Sounds like to me it's working
normally, unless you have a problem with the feedline picking up shack
or house noise.
If the noise is the normal atmospheric noise, or man made noise close
by in the area, it is working normally. In general, the better the
antenna, the higher the noise pickup. Noise is rf just like any other
signal, and follows the same rules. For general listening, you may
well find a vertical to be even noisier if the noise is local and
mostly vertically polarized. If you had it balanced in an inv vee
config, and you know the feedline was not the problem, IE: noise
ingress, common mode ,etc, it's working normally. If I have a high
man made noise level in the area, all my antennas pick up a lot of
noise. I expect them to. Truly "quiet" antennas are usually lame
antennas. Can't really say much more rationally, without knowing
where/what the noise is...I also don't know how they are feeding that
antenna. Feeding it balanced as an inv vee should be the best as far
as reducing common mode feedline problems, assuming you are using a
balun or choke. If you have the spare wire, coax, try a standard 1/2
wave dipole cut for 49m or thereabouts. Use a 1:1 balun or a coax
choke at the feedpoint. If it's noisy too, I agree with one of the
other posters...You have a noise problem, not an antenna problem. BTW,
those lower frequencies are normally noisy sounding, except maybe in
the dead of winter. Don't confuse atmospheric noise pickup as an
antenna problem. That means it's working. Unless the antenna is a
vertical, or other "incomplete" antenna that requires an rf ground
under it, there is really no reason to have to use a ground. Ground is
not a noise soak. It's a noise source. You need to find out if the
noise is from the shack, or from a distance. You can reduce shack
noise, and feedline ingress problems, but you can't do anything about
distant noise, unless you cure it from the source. MK