I got prodded into doing some investigation of scanner radios the
other day and I discovered the technology has advanced quite a bit
over the last couple years. I've long enjoyed being a Nosy Parker,
listening to police and fire radio traffic. Over the years I've had
several scanner radios, including a very good AOR handheld, but they
all were eventually made mostly useless by changes in the way public
safety radio is managed. Many communities now have trunking systems
that use sophisticated radios to share a comparatively small number of
frequencies among many, if not all, of the community's various radio
users. Trying to follow the traffic on one of these systems using a
conventional scanner is virtually impossible on a busy system. Due to
this I haven't done any public safety monitoring in several years.

My recent investigation lead me to a new scanner radio being
manufactured by GRE. GRE is better known for designing and
manufacturing scanners for Radio Shack. They made the PRO-2006, long
considered the best scanner ever made. They're now making scanners
under their own flag, and the PSR-500 is their new top-of-the-line
handheld scanner radio.

Scanners aren't usually designed to receive normal broadcast radio,
and the PSR-500 is no exception. Indeed, it isn't even capable of
receiving MW or broadcast FM frequencies. So why am I writing about it
here? It does receive the NOAA weather radio frequencies and has
features designed specifically for weather radio, including SAME codes
and specific alert filtering. I'm guessing most people won't be
rushing out to spend $500 on a NOAA weather radio, so it's a bit of a
tenuous connection to the normal ABDX areas of interest, but it's not
like we're getting inundated with equipment reviews. If you have no
interest in scanners, considering this fair warning you won't find
much of interest in what follows.

Having read of the GRE PSR-500, I took all of maybe 12 hours to give
my purchase due consideration. This is rather uncharacteristic for me,
but my long history with scanners and knowledge of trunking radio
systems lead me to quickly conclude that I'd get my money's worth from
the PSR-500. I was just about to call Universal and see if they could
overnight one to me so I'd have it to play with over the weekend, but
then I remembered AES had a store in Orlando. I gave them a call,
found out they had one in stock, and I was set for a little lunchtime
field trip. About an hour of roundtrip drive time and $530 later I was
the proud owner of a new GRE PSR-500.

The PSR-500 has an amazing array of features. As explained toward the
beginning of the 136-page manual, which is in PDF format only, GRE
spent significant time studying the way scanner hobbyists like to use
their radios. This lead to a new approach to organizing the data
maintained by the radio. Conventional scanners have always had "banks"
of frequencies that were scanned by the radio. The user would select
banks to include or exclude from the scan. More recent scanners added
some flexibility to the organization of the banks, but there was
ultimately some limit to the number of frequencies that could be put
in any bank.

For those unfamiliar with trunking communication systems, let me take
a few moments to do a handwaving explanation. Trunking systems use a
fairly small number of actual frequencies to support a potentially
very large number of agencies or "talkgroups". When a user keys up
their radio, it sends a signal on a control channel requesting a
frequency for the talkgroup to which that user belongs. The system
controller assigns a frequency to the talkgroup and commands all the
radios in that talkgroup to switch to that frequency. This all happens
almost instantaneously. The user normally notices no lag at all. The
user talks into the mic and all members of his talkgroup hear his
broadcast. And only members of his talkgroup hear his broadcast, even
though it's going over a system shared by potentially hundreds of
talkgroups.

Talkgroups are like virtual channels. Here in Orlando there is a
trunking system with over 200 talkgroups supported by 89 frequencies
used by 8 different transmitter sites. These is some re-use of the
frequencies by different sites. I'm not sure how many unique
frequencies are in use. This system is used by the Orlando PD, Orlando
FD, the county sheriff's office (over 70 talkgroups right there),
county fire, county jail, county services, county schools, the
airport, the buses, the Amway Arena, etc. And that's just one trunking
system. There are 24 trunking systems in use in the Orlando area. Most
of them are privately owned and are much smaller.

This plethora of trunking systems and talkgroups prompted GRE to take
a different "object oriented" approach to memory organization. The
radio essentially has a database of up to 1800 scannable objects in
main memory. These objects can be associated with one or more of 22
lists the radio can scan. The scannable objects can be single
conventional frequencies, talkgroups, frequency range searches,
specific service searches, or "sweeper" searches. The radio also has
storage for up to 20 additional copies of main memory configurations,
referred to as V-scanner folders. So you can have available in the
radio, 20 different archived sets of up to 1800 objects and 22 lists,
plus one active set.

GRE used this massive amount of storage to pre-load the PSR-500 with
commonly used frequencies for most of the population centers in the
United States. The Orlando area was included, but, I must admit, they
screwed up the control channel frequencies for the Orlando/Orange
trunking system. At first I thought my radio was defective when I
selected the proper "folder" and scan list, yet heard nothing. When I
changed the TSYS object to include the right control channel
frequencies the radio came to life.

Each scannable object can have a 16-character tag associated with it.
This is critical with the trunking systems since there can be so many
talkgroups and each is natively identified by a simple number. Each
object also has a number of other characteristics that control how the
scanner reacts when that object becomes active. It even has a hit
counter for each object so you can keep track of which frequencies or
talkgroups are most active.

One of the most useful features I've not seen before is a tri-color
alert LED on the top front of the radio. You can select one of eight
different colors to be display on the LED when a scan object becomes
active. Even if you're far enough away that you can't read the
display, a quick glance from across the room can give you some
indication of what object has become active. I currently have mine set
with blue for police and red for fire. I haven't figure out what to do
with the other colors just yet. There is also a flash feature that
I've used to indicate calls that are in my sector. If I see the light
flashing, I know to pay closer attention.

The display is a 5-line dot-matrix with an orange backlight. The keys
light up with the same orange light. The display is one feature where
there seems to be some question as to whether GRE made the proper
design decisions. There is data displayed here that's of questionable
use during many operations, leaving just one line for the definitely
useful data. The result is the talkgroup and talksystem alternate
display on the same line. The radio does have upgradeable firmware, so
it's possible this is something that can be addressed in the future.

The house I'm living in borders the property of a large
hotel/recreation complex that has an older trunking radio system. I
found some data on this system on a scanner web site, but it turned
out there were some inaccuracies in the data that resulted in the
radio not picking up anything. After reading a bit more and just
poking around in the myriad of features on the radio, I discovered an
"Analyze" function for the trunking system. This simply camped on the
system and displayed the talkgroup codes of all the transmissions that
came in. I was able to find the problems with the data I got from the
web site and correct them. Now I can hear everything that's going on
at the hotel next door. (There's nothing quite as exciting as finding
out that the light in the mini-bar in room 4035 is out.)

The search functions supported by the PSR-500 are interesting. There's
a simple limit search where you specify a start and stop frequency and
a step value. The radio simply goes through the specified range and
stops on any active frequencies. This has been a common scanner
function for many years. The only new thing with the PSR-500 is that
limit searches are scannable objects just like any other, so you can
have as many of them as you want and can add them to the scan lists.

There are also "service" searches. These are similar to limit
searches, but allow multiple search ranges to be grouped together for
"services" that typically use disjoint frequency segments. There are
pre-defined service searches for services such as public safety,
aircraft, ham, CB, marine, and FRS/GMRS.

One of the more interesting features of the PSR-500 is the spectrum
sweeper object. This combines the functionality of a frequency scanner
with a more typical limit search. The radio looks for strong signals
in broad frequency segments and then does a detailed conventional
search through the segments that show activity. This is supposed to
find more active frequencies than a more conventional frequency
counter would. For instance, the VHF aircraft band covers 108-137MHz.
A conventional search of this range would take quite a while and would
be likely to completely miss intermittent exchanges. With a sweeper
search, the radio looks for any significant activity in each of the
1MHz segments and then does a detailed search of just the active
segments. This greatly increases the odds of catching an exchange.

Since NOAA weather radio is the only real connection to this group, I
should probably say a bit about the capabilities in this regard. The
NOAA weather frequencies are pre-programmed and there is a dedicated
WX button on the radio. Press the button and the radio locks on to an
active weather frequency. Press the up or down key to search for
another station. It works in scan mode, so weak stations are likely to
be skipped. When DXing WX, the squelch needs to be turned all the way
down so the radio won't automatically look for an active frequency.

There is a weather priority mode that periodically checks the weather
channel for the all hazards warning alert tone. If the tone is
present, it tunes the radio to the weather channel. It can be set up
to do this while scanning other channels, so you don't have to abandon
normal scanning activities to keep up to date with weather alerts.

There is also a SAME standby mode that works in a similar fashion, but
looks for the specific SAME codes you've programmed. This will
override normal operations only when an alert comes in for an area
you've designated. You can filter it even further by specifying event
codes to allow or ignore.

In the testing I've done so far my Reecom weather radio seems to be
more sensitive than the PSR-500, but I'm not convinced that's really
the case. The antenna on the Reecom is optimized for the WX
frequencies. So far I've only used a rubber ducky antenna on the
PSR-500. These antennas tend to be optimized more for the 800-900MHz
range used for public safety, not for 162MHz where the weather
broadcasts are. I will eventually get another antenna that will let me
better judge the PSR-500's WX DXing capabilities.

The PSR-500 comes with a computer interface cable. The radio itself
has a two-pin RS-232 serial interface. Recognizing that few computers
come with serial ports anymore, GRE included a USB-to-serial cable
that allows you to connect the radio to any USB port. There is some
software that comes with the radio, but, like most free software
provided by the manufacturer, it's pretty limited in function.
Thankfully, there are at least three different inexpensive software
packages available for managing the memory in the PSR-500 and actively
controlling the radio. You can do from the front panel of the radio
everything you can do from the software, but programming more than a
few talkgroups directly on the radio quickly becomes very tedious. The
software makes it far easier.

I've probably skipped over about 80% of the features and functions of
the PSR-500 in this review. I'm sure I'll still be discovering new
features a year from now.

-- Jay