View Single Post
  #8   Report Post  
Old April 4th 07, 04:47 AM posted to rec.radio.amateur.antenna
Richard Clark Richard Clark is offline
external usenet poster
 
First recorded activity by RadioBanter: Jul 2006
Posts: 2,951
Default Non technical antenna question

On Tue, 3 Apr 2007 23:06:19 -0400, "Pete" wrote:

Thank you Richard...that is the kind of comment I was looking for (I took
Neil's with a grain of salt-there is absolutely nothing wrong with the
radio). I was trying to be polite in my post, but I am way smarter than
that.


Hi Pete,

No, it is still advice to consider. Your new radio does have the
performance of a lemon in comparison to your old set.

I will try wrapping the wire around the antenna tomorrow and let you know
what happens (is it okay to use phone wire which has several individually
insulated wires in it). BTW could you please tell me why the reception
comes in when I put my hand around the antenna (ie what is my body doing to
the signal), and also answer my second question about one antenna for both
AM and FM. Thanks again...Pete


Yes, it is a mystery still....

Your body is a conductor, admittedly a very poor one, but the power
levels we are talking about, and the currents involved don't ask very
much. The wavelengths involved for FM are about your height. If we
shift to AM, you would have to be the Jolly Green Giant (hence hand
waving usually doesn't do much good). That you don't even have to
touch the antenna is also an indication in the small power necessary,
it is more about your height and proximity.

Multi wire, such as you have, will make little difference. However,
this is not to say that things won't remain marginal. You do have the
experience with another radio that works in the identical environment,
so that suggests some hope. There are "magic" lengths of wire, but
you can escape that discussion by crafting various different lengths
by bending, trimming, but still keeping things high (all of this is
predicated on putting the antenna into the sight of the transmitter).

The same antenna is NOT for both bands. The AM antenna is undoubtedly
the old stand by we call the loopstick. This is a long rod of ferrite
material with a coil or wrapping of wire - you've probably seen these
before. A car antenna certainly does double duty, but this is not
generally found in portable radios. This is because the car radio
sits inside a metal cage that demands an external sky hook.

73's
Richard Clark, KB7QHC