Is that normal for scanners to sometimes just miss messages even
though a scanner next to it is getting the message and the one is just
sitting there doing nothing? My mother has a 10-13 year old radio
scanner desktop that sometimes seems to get messages in our house
before my scanner gets it or my scanner will repeat it (Uniden
BR330T). I noticed when I listen to my local bus, it seems my Uniden
will sometimes miss a part of all of a message but my other scanner
doesn't seem to miss as much with it. I know it misses because when I
sit on a bus, the driver's radio hears everything but while a message
is playing on the driver's radio, my scanner is picking up nothing or
waits a while to hear anything. Can the bus be blocking my scanner and
the bus antenna be outside? I noticed AM radio and shortwave is almost
dead on the bus, why? You can hear scanners in cars I believe, so why
not buses?

Does the more channels worsen the scanner?

On Feb 27, 10:16 am, "RedPenguin" wrote:
Is that normal for scanners to sometimes just miss messages even
though a scanner next to it is getting the message and the one is just
sitting there doing nothing? My mother has a 10-13 year old radio
scanner desktop that sometimes seems to get messages in our house
before my scanner gets it or my scanner will repeat it (Uniden
BR330T). I noticed when I listen to my local bus, it seems my Uniden
will sometimes miss a part of all of a message but my other scanner
doesn't seem to miss as much with it. I know it misses because when I
sit on a bus, the driver's radio hears everything but while a message
is playing on the driver's radio, my scanner is picking up nothing or
waits a while to hear anything. Can the bus be blocking my scanner and
the bus antenna be outside? I noticed AM radio and shortwave is almost
dead on the bus, why? You can hear scanners in cars I believe, so why
not buses?

Does the more channels worsen the scanner?

Speaking of the Uniden BR330T, does anyone know if it charges the
batteries with the scanner turned on and plugged in instead of being
off where it says Normal Charging? Also what is on 589-595MHZ range?
Every time I put on close call or search this range, my BR330T stops
and just leaves a static channel that I have to lock out. It's all
static on every channel in that range.

"RedPenguin" wrote in
oups.com:

Is that normal for scanners to sometimes just miss messages even
though a scanner next to it is getting the message and the one is just
sitting there doing nothing? My mother has a 10-13 year old radio
scanner desktop that sometimes seems to get messages in our house
before my scanner gets it or my scanner will repeat it (Uniden
BR330T). I noticed when I listen to my local bus, it seems my Uniden
will sometimes miss a part of all of a message but my other scanner
doesn't seem to miss as much with it. I know it misses because when I
sit on a bus, the driver's radio hears everything but while a message
is playing on the driver's radio, my scanner is picking up nothing or
waits a while to hear anything. Can the bus be blocking my scanner and
the bus antenna be outside? I noticed AM radio and shortwave is almost
dead on the bus, why? You can hear scanners in cars I believe, so why
not buses?

Does the more channels worsen the scanner?


Desktops tend to have better sensitivity than handhelds, but thats a general
statement.
The only way to really compare would be to tap into the same antenna feed.
Turn down the squelch as far as you can, make sure theres no ATT engaged, and
thats about all you can do with a handheld ... Though frquently upgrading
stock antennas helps too.

RedPenguin wrote:
Is that normal for scanners to sometimes just miss messages even
though a scanner next to it is getting the message and the one is just
sitting there doing nothing? My mother has a 10-13 year old radio
scanner desktop that sometimes seems to get messages in our house
before my scanner gets it or my scanner will repeat it (Uniden
BR330T). I noticed when I listen to my local bus, it seems my Uniden
will sometimes miss a part of all of a message but my other scanner
doesn't seem to miss as much with it. I know it misses because when I
sit on a bus, the driver's radio hears everything but while a message
is playing on the driver's radio, my scanner is picking up nothing or
waits a while to hear anything. Can the bus be blocking my scanner and
the bus antenna be outside? I noticed AM radio and shortwave is almost
dead on the bus, why? You can hear scanners in cars I believe, so why
not buses?

This is the start to a long and difficult answer. I'll shorten and dumb
things down a bit so that you can understand fundamentals.

First, scanners need to cover very broad ranges of frequencies. This
means they can often go deaf in the presence of strong nearby signals.
It's like trying to hear someone speaking softly on the other side of a
very noisy room. If you had some way of reducing the ambient noise
(such as filtering the extraneous sounds out) then you might hear more.

There are receivers which can do better, but they use more power and
they need more filters. Thus, handheld scanners with limited battery
life and little space available for filtering typically do worse than a
table top scanner with more power and more filters available to use on
the first few stages of the receiver. This feature is known as dynamic
range among radio enthusiasts and engineers. It is a major
consideration when purchasing a scanner. I could go in to the methods
for describing how this works, but people write books about this stuff.

Second, there are issues of scan rate and squelch reaction time. If
your scanner only passes by your frequency once every three seconds,
it's possible to miss an entire message on a channel. There is also an
issue of how weak the signal may be. It may be weak enough that while
scanning, you'll set the squelch such that the scanner triggers
spuriously on stray signals. Again, you'll miss signals when the
scanner gets "stuck" on a channel where it thinks there is a signal.
And meanwhile, the traffic on another channel goes by unnoticed.

Third, there is an issue of spurious signal reception. Most scanners
have what are known as "birdies." Birdies are the result of spurious
mixing products generated in the scanner itself. All scanners have
them. However, in the better scanners, the microprocessor takes
measures to hide them. You could get stuck trying to hear a birdie on
older scanners.

Does the more channels worsen the scanner?
It can. That largely depends on how fast the scanner scans and how long
the signals stay on the air. I usually set up banks on my scanner for
specific purposes. For example, I'll set up a bank for air traffic
scanning. A bank for monitoring my local fire frequencies, and a bank
for monitoring County and State Police in my area. I don't usually
leave all banks on all the time. First, it's pretty confusing. Second,
there is too much to listen to, and the scanner doesn't get through all
the channels in a timely fashion.

Think about what you're going to listen for, and then customize the
scanner's behavior for that purpose. You can't hear everything all the
time. It's confusing, there will be gaps when more than one group is
talking at the same time, and you'll have a hard time keeping track of
it all.

Good luck, and happy monitoring!

Jake Brodsky
Amateur Radio Station AB3A