Wimpie wrote:
Hello Bob,

On 14 ene, 19:44, "Robert11" wrote:
Hi Harry,

Great explanations. Thank you.

I will try to build your suggested antenna first chance I get. Will let you
know how it works out.
BTW: is this what's (also) called a "J Pole" ?

Should it be pointed in any specific manner toward the source of what you
are trying to receive ?
e.g.: should a plane formed from the short & long lengths be pointed to the
source ?

Q1: I have no idea how it's constructed, but what I describe as vertical,
the "tube" of the antenna is true up-down vertical.

Q2: Signal is "fairly" strong; it's only the noise that makes it hard to
listen to when held vertically in the normal manner. Much better
horizontally, and vertically downward, like I mentioned.

Are you sure that it is noise, is there some speech or music in the
"noise"? It could be an intermodulation product or just overload to
your receiver from a local FM broadcast station. See what happens
when you listen outside. when it is interference from your own
domestic equipment, the level should drop when outside your house.
Many so called "wide band receivers" give problems when used with a
good outdoor antenna.

Wim
PA3DJS
www.tetech.nl

[rest deleted]

it is not unusal for the transmiters at an airport to produce a huge
amount of interrmod. This is because you may have a dozen or more
transmitters all keying at once and their antennas are closely spaced
often only 4 to 6 ft apart. This is not usally a problem for air
traffic control because the receivers are remotely located from the
transmitters often a mile or more separating the two. On the occasion
this is a problem circulators are placed on the transmitters to
eliminate the intermod'

If you are a good distance from the tx site and are still experiencing
an intermod probllem it is because the mixing action is taking place
in your rx in instead of the transmitters.

Jimmie

Jimmie