On 05/07/2011 07:28 PM, D. Peter Maus wrote:
On 5/7/11 16:58 , Mike S wrote:
I was just given a Grundig YB400PE without the external antenna, and
the shortwave reception inside my mobile home (metal box) without an
external antenna is non-existent. After reading several of the
antenna discussions here I was wondering if I could get
recommendations about the best way to build an outdoor antenna. I
can put up a large diameter loop outside, say up to 6 feet diameter,
mounted above the roof, or I could run a straight wire about 40'
running roughly East-West above the roof, or a combination of the
two if that would help.

When I was a kid my dad bought a Hallicrafters shortwave, I think it
as an SX-99, and he used the heavy dog run wire mounted about 10'
above the ground, running from the house to a tree in the back yard
oriented roughly North-South with no ground (neither of us knew
anything about electronics then), and I got stations from all over
the world, it was really interesting hearing the programming from
other political slants as a kid. So I'm wondering how much I can
pull in with this cheap little model.

TIA,
Mike


It's actually quite sensitive, as portables go. An external antenna will
do quite nicely.

Being quite general, here...as a quick starter, a wire, 10-20 feet long
is all that's necessary. More than that and you may be subject to
overload of the front end, which will create artifacts up and down the
dial.

A decent ground may or may not benefit you. Your receiver input isn't
like the input on your SX-99. Working against a ground isn't necessary
with some solid state designs. YB400PE is one of them.

That is, unless you transform the input. Then you'll work the antenna
against an earth ground on the antenna side of the transformer, and the
receiver on the other. This will reduce some noise, mostly electrical.

More elaborate installations are possible, and some may work quite
nicely, like trapped dipoles, for instance. And of course, always
experiment. There are programs that can even model you an antenna to
suit your specifics. And Kevin, here, has done that in the past for
another member. But to get you started...a wire is all that's necessary
to bring your SW bands to life.

I'd try to use the whole mobile home as an antenna. Use a capacitor to
connect the frame to you antenna input. Cheap experiment, sometimes
works. NOTE: a clip lead and a piece of PVC tape for DC blocking = a
capacitor.