Car antennas

[Dan.Strassberg]

There seem to be two styles of the latest roof-mounted antennas. Some
have a very short--maybe 2"--projection out of a base that might
measure as much as 2x4x1-in. Others seem to be somewhat longer but
have a smaller base. The larger-sized base appears to be easily large
enough to accommodate an amplifier, whereas I imagine that antennas
that use a smaller base must have their amplifiers elsewhere (trunk?
between headliner and roof?). I suppose each configuration has its
advantages and disadvantages, but intuitively, the idea of having the
amplifier right at the base of the antenna makes more sense to me. I
do remember hearing, though, that early antennas with the amplifier
inside the base were prone to failure because the sun shining on the
black plastic base could produce temperatures inside the little
enclosure that were so high they caused the ICs inside to fail.
Once the warranty ended, replacement costs were not trivial--in the
$300 area, IIRC.

-----
Dan Strassberg (dan.strassberg@att.net)
eFax 1-707-215-6367

----- Original Message ----- 
From: "Larry Weil" <kc1ih@mac.com>
To: <boston-radio-interest@lists.BostonRadio.org>
Sent: Monday, May 10, 2010 12:42 AM
Subject: Re: Car antennas


> At 12:04 AM -0400 5/10/10, A. Joseph Ross wrote:
>>Having recently been car shopping, I've noticed that radio antennas
>>have changed again.   My old car had a retractible whip antenna that
>>went up when the radio was turned on and down when it was turned
>>off.
>>  I had to replace that once in the life of the car, and it was
>>already not going down all the way again.
>>
>>I notice that a lot of newer cars have a small antenna, about six to
>>twelve inches, above the rear window.  I wondered whether that would
>>be sufficient for decent reception of AM and FM stations, but when I
>>tested this on cars that I test-drove, it seemed to work.  Why is
>>this antenna adequate?  Will it also work for satellite radio?
>>
>>Other cars have an antenna embedded in the rear window.  I had a
>>1977
>>Oldsmobile that had the antenna embedded in the front windshield.  I
>>suppose embedding it in the rear window is about the same thing.
>>The
>>antenna looks like a typical FM dipole.  Why does this work for AM
>>as
>>well, as it does seem to?
>>
>
> The window antennas were notoriously bad, although the later ones
> were amplified.  Usually the amplifier is under the trim near the
> rear of the car.  The short ones are also amplified.  Some of them
> also have a satellite antenna built into the base, though some cars
> use a totally separate antenna for satellite.
>
> -- 
> Larry Weil
> Lake Wobegone, NH