View Single Post
  #12   Report Post  
Old April 4th 07, 08:06 PM posted to rec.radio.amateur.antenna
Pete[_3_] Pete[_3_] is offline
external usenet poster
 
First recorded activity by RadioBanter: Apr 2007
Posts: 7
Default Non technical antenna question

Richard Clark wrote:
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.


Hi Richard...Make sure to read Michael Black's interesting info in this
thread. I definitely believe the radio (cheap as it may be) is doing
exactly what it is designed to do. I do not believe it is a lemon, and
there is no doubt in my mind the older Panasonic has better circuitry in it
(it is a better set and has a graphic equalizer also - the newer one doesn't
even have bass/treble controls but it sounds good), but they are roughly
comparable.

Actually, the old one probably costs quite a bit more (on a relative basis)
considering how cheap you can buy this stuff these days compared to the
price twenty years ago. Just for your info, I have an old Electrovoice
stereo receiver downstairs (with dials/knobs) and it still works fine after
36 years.

Also FYI, I have a new Sherwood stereo receiver upstairs (with the fm
antenna that came with it installed), and it also picks up the station I am
talking about weaker than the other stations, but I was able to tweak the
antenna and it comes in acceptable. It is interesting that the old
Panasonic boombox has no trouble. Sorry if I am going off on a tangent. I
have more comments below :-) ....Pete



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


Thanks again Richard for all the good info. I kind of knew about the
loopstick stuff but just wanted to make sure. You guys have been
great...Pete