Posted by Watson A.Name - \"Watt Sun, th on September 8, 2004, 10:35 am
> On Wed, 14 Jul 2004 08:14:26 -0700, Jim Michael wrote:
> > I just got a 2004 Prius Package 7. The radio reception is terrible!
> > Has anyone else had this problem? Jim
> I find the reception in the package 9 to be outstanding. FM
sensitivity
> is excellent, and AM sensitivity and selectivity is incredible. There
is
> a local AM tower next to the freeway here in Santa Barbara that
carries
> three local stations at 1290, 1340, and 1490. I can drive the freeway
> past the tower and listen to 1450 in Ventura about 30 miles away
without a
> hint of interference. Every other car I've driven has failed
miserably in
> this respect, with intermodulation and overload for about half a mile.
I've never heard of one tower supporting multiple AM stations, because
the tower is the actual antenna; for more than one station, it means
they would have to have some kind of isolation between the two
transmitters to keep them from each other. This leads me to beliwve
that maybe you're not really receiving that many stations on that tower.
Maybe you're getting interference from more than one station at that
location by intermodulation, where the station is acting like a local
oscillator in your radio, and causing it to receive two at the same
time.
> I have had some issues with the CD changer occasionally giving a
"Check"
> message on some disks. Selecting a different disk and coming back to
the
> failedone seems to fix it. I'm going to try swapping the disks around
to
> see if it is the disk or the slot. I use the random across all disks
> setting which exercises the changer mechanism a lot more than
listening to
> a single disk at a time.
Posted by Jay Hennigan on September 28, 2004, 12:25 am
On Wed, 08 Sep 2004 03:35:59 -0700, Watson A.Name - "Watt Sun, the Dark
Remover" wrote:
>> On Wed, 14 Jul 2004 08:14:26 -0700, Jim Michael wrote:
>>
>> > I just got a 2004 Prius Package 7. The radio reception is terrible!
>> > Has anyone else had this problem? Jim
>>
>> I find the reception in the package 9 to be outstanding. FM
> sensitivity
>> is excellent, and AM sensitivity and selectivity is incredible. There
> is
>> a local AM tower next to the freeway here in Santa Barbara that
> carries
>> three local stations at 1290, 1340, and 1490. I can drive the freeway
>> past the tower and listen to 1450 in Ventura about 30 miles away
> without a
>> hint of interference. Every other car I've driven has failed
> miserably in
>> this respect, with intermodulation and overload for about half a mile.
>
> I've never heard of one tower supporting multiple AM stations, because
> the tower is the actual antenna; for more than one station, it means
> they would have to have some kind of isolation between the two
> transmitters to keep them from each other. This leads me to beliwve
> that maybe you're not really receiving that many stations on that tower.
> Maybe you're getting interference from more than one station at that
> location by intermodulation, where the station is acting like a local
> oscillator in your radio, and causing it to receive two at the same
> time.
It is quite common. Typically separate transmitters and a matching
circuit called a diplexer. Another technique is a singler broadband
power amplifier being driven by separate exciters for the different
frequencies. The matching circuits are somewhat complex as the antenna
itself will be off-resonance for at least some if not all of the
frequencies in use.
http://beradio.com/departments/radio_diplexing_am_transmitters/
http://www.crawfordbroadcasting.com/~cbc/Eng_Files/Practical%20Diplexing.pdf
> > I just got a 2004 Prius Package 7. The radio reception is terrible!
> > Has anyone else had this problem? Jim
> I find the reception in the package 9 to be outstanding. FM