🚀 go-pugleaf

In git.general The Evil EE Minion <fh28@prism.gatech.edu> wrote:
> Chris Sidi wrote:
>> the radio in realaudio.  The tuner came with a cheap T-shaped ~6 feet wide
>> wire antenna (dipole?).  

> Well this is the first problem. FM is circularly polarized, but a dipole
> is linearly polarized - so you lose half your sensitivity right there (a
> loss of 3dB in received power)

Why do people make FM dipole antennas then? IIRC, radio shack sells a
T-shaped antenna for FM, and this card came with one and this web page has
directions for a dipole: http://www.northcountryradio.com/fmdip.htm

>> If I join the arms of antenna together (and maybe wrap it into a 5 inch

> Wrapping it up adds a circularly polarized component :) 

Actually, the WREK engineer who suggested it wrote me back, and he says he
suggested the ball because it attenuates all the signals moreso than
providing stronger signals:
=====================================================================
But from homepark your main problem is that of all the stations you
receive, some of them are so strong that the front end of the receiver
gets overloaded. Once overloaded it doesn't pick up the weaker stations
well even though their signal strength is at a normally sufficient level.
Basically, when the front stage is overloaded its dynamic range is
compressed. 

So if you attenuate the whole signal from your antenna you can move the
stronger stations down to a level where your receiver is not overloaded
and thus even though the weaker stations were also attenuated they are
still usable because your receiver is now working properly and is
operating at its full dynamic range. 

>From a theoretical point of view, use a nice dipole antenna, properly
installed, then just before the input to the receiver run the leads
through an H pad that knocks it down about 10 to 20 dB. The H pad should
have 600ohm in and 600ohm out. It can easily be made out of 5 resistors. 

I have also had very good success with a Radio Shack desktop FM amplified
antenna. It runs on a little wall transformer.  And has a tuning knob
which tends to attenuate the signals not tuned to and thus lowers the
stronger stations unless they are real near the station of interest. 

Wading the antenna up into a ball has worked several times.  But
basically, I was counting on the improper ball of antenna to pick up
poorly and thus attenuate the signal without the user having to go to the
trouble to build a proper H pad.  And more often than not it worked. But
it's just a gamble.  It is possible that the ball will just happen to
resonate at the unwanted frequency instead. 
=====================================================================

-Sidi, dumb