Newbie advice on aerials

Newbie advice on aerials

Post by T. J. » Tue, 25 Feb 1997 04:00:00


> Hi all!

> Does the direction and polarisation of an aerial matter for shortwave?

> I know that for FM the signals are polarised, and that for AM/MW
> there's still the matter of directionality (i.e. direction of the
> ferrite rod), but what about shortwave?

> Also; lengths!

> Should I try to be getting around 1/4 wave length, or does it tend not
> to matter too much?

> Once you've bunged an aerial (make-shift or otherwise) up, do you need
> to play around with it much?

> Love
>   Julie (with a Roberts R861/Sangean ATS-909 with only the included
> telescopic and wire aerials that were supplied).

Not really, although as you advance you can find some interesting
experiences by using a pair of antennas with different polarization. For
now hang that wire antenna so that it slops from a high point to a low
point will probably capture tons of signals and get you started on the
right path. As a mater of fact you will be surprised how much you can
catch with just that telescopic antenna. Worry less about polarization
and concentrate on listening. That is where you want to advance your
skills for now. The rest will come.
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Newbie advice on aerials

Post by David Rickme » Wed, 26 Feb 1997 04:00:00




>Does the direction and polarisation of an aerial matter for shortwave?

The "incoming angle" is more important than the polarization.
Generally, DX comes in at low angles.  An antenna close (less than 1/2
wave) to the ground tends to favor high angle waves.
Quote:>Should I try to be getting around 1/4 wave length, or does it tend not
>to matter too much?

An external wire antenna starts to work well once you exceed 1/4 wave
at the lowest frequency of interest.
Quote:>Once you've bunged an aerial (make-shift or otherwise) up, do you need
>to play around with it much?

Ideally, No.
dr
 
 
 

Newbie advice on aerials

Post by Sander Schimmelpennin » Wed, 26 Feb 1997 04:00:00


>An external wire antenna starts to work well once you exceed 1/4 wave
>at the lowest frequency of interest.

..unless your radio incurs front-end overloading. In that case, get the
cheapest wire you can get, start with the greatest possible length, and reduce
it until overloading changes. Then install a wire that is strong enough to
withstand strong winds. By the way, disconnect your antenna from the set when
lightning may occur or when you are away for more than a day.

Sandy
Oakville, Ontario

 
 
 

Newbie advice on aerials

Post by Thomas R. Sundstro » Wed, 26 Feb 1997 04:00:00


> Does the direction and polarisation of an aerial matter for shortwave?

For the purposes of helping your portable to hear more stations, no.
Take a look at Radio Netherland's Antenna Advice at
<http://www.rnw.nl/en/pub/antenna/aa_index.html> for some information on
antennas. Hope that helps.

Tom Sundstrom

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