This month, the subject is scanning. Our guest is collector and radio
hobbyist Ed O'Connell. Also this month, your answers to my question of
"what was last year's best Code 3 model?" More on that later.
Ed O'Connell is a part-time emergency medical dispatcher for a
two-and-a-half county area in northern New Jersey, as well as an EMT and
licensed amateur radio operator. He's also a builder of scale emergency
vehicles, and serves as the secretary, treasurer, and newsletter editor of
Metropolitan Miniature Fire
Apparatus Association. He's been interested in scanners since first
volunteering with his local rescue squad in 1980.
Mike: Ed, what is scanning?
Ed: Scanning is short for
scanner monitoring or monitoring two-way radio traffic using a scanner.
Scanning is also hobby enjoyed by many people who are interested in
knowing what is happening around them. Some may be on and off-duty
emergency service providers who want to keep abreast of what is occurring
in their town as well as in neighboring communities. Others are radio
hobbyists and ordinary citizens who want to hear news as it is happening,
or want to be in on the action from the comfort of their living room.
Scanning is a great way to be notified of an emergency situation that may
affect you, your family, or your town. You may learn about an evacuation
order due to an approaching severe weather situation, a hazardous material
incident, or a rapidly spreading fire. These days, being prepared is not
an option. Having a few extra moments notice can make a big difference.
M: What is a scanner?
E: A scanner is a type of radio
receiver that became popular in the 1970s and that rapidly changes
channels looking for radio traffic on specific frequencies. Unlike your
favorite broadcast AM or FM radio station, which constantly sends out a
signal, two-way radios use a particular frequency for a short time and
then it is dormant until the next transmission.
In the early 1970s, multi-band portable radios received broadcast AM/FM as
well as other popular monitoring bands that included public safety
frequencies. Users would tune around the band to find their local police
or fire frequency. Unfortunately, this was the only frequency they could
listen to at that time, and if nothing was happening, the radio was
M: So in order to find any
action, the user had to manually tune up and down the band looking for
E: Yes. The scanning radio, or
scanner, was developed to repeatedly sample a set of specific frequencies,
stopping if it detected a signal and resume scanning after that signal
stopped. Early scanners were crystal-controlled, requiring one for each
channel you wanted to monitor. Most crystal scanners had eight channels;
others were available with four, six, or ten channels. Crystals cost about
$5 each back then, so if you wanted to listen to many frequencies, it
tended to get expensive. It also meant swapping out the crystals from time
to time if you liked monitoring more frequencies than the scanner had
M: When did programmable
scanners first appear?
E: Programmable scanners were
developed in the early-1980s. Crystals were no longer needed and changing
frequencies was as simple as pushing a few buttons. This was great news
for those who liked to monitor lots of frequencies, or several sets of
frequencies, such as when traveling or during special events or certain
times of the year.
As communications technology advanced quite rapidly through the rest of
the century, newer scanners added new bands such as the 470-512 MHz T-band
and the 806-956 MHz 800 band. Newer features included more memory channels
(100, 200, 500, even 1000) divided into manageable 10, 20, or 50-channel
banks, as well as the capability of searching within two frequency limits.
Searching enabled scanner users to monitor activity over a range of
frequencies without having to enter each individual frequency.
High-end scanners offered alphanumeric displays and/or coded squelch
systems. Coded squelch is used when different agencies operate on the same
frequency, such as two police departments 25 miles apart. A sub-audible
tone is carried along with the radio signal. Unless the tone matches the
receiver, the channel stays quiet. So if two towns use the same frequency
but different sub-audible tones, and you are only
interested in monitoring one of them, having a scanner capable of
decoding these tones is necessary to keep their transmissions apart.
M: What is a trunking scanner?
E: As existing frequencies
became busier, public safety agencies needed additional channels for
command and tactical operations. Unfortunately, no frequencies were
available in most metropolitan areas. A new technology called trunking was
developed to make efficient use of a limited number of frequencies. Since
almost all frequencies are not "in use" at all times, several agencies
could share the same group of frequencies, each assigned something called
a talk group. An entire town could operate on the same trunked system,
instead of each agency on its own frequency. Small trunk systems use five
frequencies while larger systems can have up to 30. And as usage grows,
additional talk groups are added using the same group of existing
M: Can you give an example?
E: Let's say your town has
separate dispatch and operations frequencies for police, fire, and EMS.
Thatís six channels right there. Add additional frequencies for public
works, animal control, the street department, the water department, the
senior citizen's bus, and some extra fireground and detective channels,
and it adds up. The frequencies might be on different bands as well;
police on UHF, EMS on VHF, fire and other municipal services on low band.
Because of the broad range of radio spectrum covered, interoperability is
impossible without having the other agencyís radios in the vehicles.
M: How do trunking systems work?
E: In a trunk system, a control
channel maintains the status of the system through a computer. The
remaining frequencies are used for voice traffic. Each radio is assigned
to one or more talk groups. Talk groups are virtual channels; the voice
frequencies are like chat rooms. When a radio user keys the microphone,
the computer sends a signal to the other radios in that talk group and
assigns an available frequency to use for that transmission. Once the
message is sent, and the frequency is no longer in use, it becomes
available again. A reply may or may not be on the same frequency. If
all frequencies are in use, a busy tone is sent to the user keying the
microphone, and he has to wait until a frequency is free. Different
priorities can be assigned to talk groups, so police, fire, and EMS have
priority over public works, animal control, and the senior citizen's bus.
M: What if your scanner can
receive the trunking frequencies, but isn't a trunking scanner?
Most scanners are capable of monitoring the frequencies used by trunk
systems, but do not have the capability of following the talk groups. In
those cases, users scanning through the frequencies will hear fragments of
conversations of all the users of the system, as well as the
computer-generated data noise on the control channel.
M: Can all trunking scanners
tune into all trunking systems?
E: Not necessarily. There are
three main analog trunking system protocols used in the United States. All
three use proprietary infrastructure, and are not compatible with each
other. Motorola, the most popular, has what they call Type I, Type II, and
Type IIi systems, which is a hybrid between the first two. EDACS (GE, Ericsson, M/A-Com) is the second most popular, followed by LTR (EF
Johnson), which is mostly used by businesses.
If you want to monitor a trunked system in your area, make sure you have
the proper scanner by knowing what particular system(s) are used. Not all
scanners can follow all systems and spending a few hundred bucks on the
wrong type of scanner can be a costly disappointment. I know, it kind of
happened to me. The neighboring town uses a narrow-band EDACS system and
my two primary scanners are not compatible with it. They can follow an
EDACS system, just not a narrow-band one. But these two scanners have
several of the features I need, so I had to sacrifice monitoring this one
M: What is a digital trunking
E: The latest top-of-the-line
scanners are analog trunking models with added circuitry to receive
digital signals. Several years ago, the Association of Public-Safety
Communications Officials (APCO) supervised the development of a digital
communications technology called Project 25. Interoperability between
users was a key initiative. They also wanted to avoid the proprietary
system issues that occurred with analog trunking. APCOís Project 25
established a standard for digital radios that all manufacturers had to
meet to assure interoperability. Digital technology makes more efficient
use of the radio spectrum by allowing closer channel spacing than analog
communication. The radio converts the voice message into a digital packet
and the receiver converts the digital information back into voice. Analog
scanners lack the circuitry to convert the signal back to voice, so
transmissions sound like static.
M: Are digital trunking systems
E: Digital public safety
communications isnít widely used right now, but some agencies have adopted
the technology. Others are reluctant. Like any new technology, digital systems have their
detractors. Some users have complained about audio and signal quality,
other users have questioned the reliability of the systems. Since digital
systems are new, it is also an expensive project for a town to purchase
all-new equipment. If digital systems are in use in your area, you must
have a digital scanner to monitor them. Digital-capable scanners are
relatively expensive, but as demand increases, prices should come down.
M: How does a buff start
E: Itís as simple as finding
out the frequencies used in your area, getting a scanner capable of
monitoring those frequencies, and then sitting back to enjoy the action.
Scanning is a dynamic hobby; the more you participate in it, the more you
quickly learn about it. Your first scanner can be a lower-end model. In
fact, an entry-level scanner is the best bet for a newcomer, as
programming the advanced models can be a bit tricky and time consuming.
You can get a good basic scanner for under $100. The latest
digital-capable scanners cost around $500.
M: Where can they find
E: There are many places where
frequency information is available. Numerous books have been published;
some are much better than others.
Scanner Master publishes several
excellent regional frequency directories edited by local hobbyists. The
directories list not only the frequencies, but also the actual channel
usage, and are broken down by state then by county. Some listings include
coded squelch information and even vehicle numbering schemes. The old
stand-by book, Police Call, is available in several volumes
covering several states. The book contains a vast amount of raw frequency
data arranged by state and then by town. While the information is good, it
can be difficult to determine the use of each frequency listed.
The internet also has numerous scanner-related discussion groups with
links to various sites with frequency information. As with books, the
quality of the information varies widely. Search the internet for
frequencies and discussion groups.
Yahoo Groups has many such groups
under the topic hobbies/amateur & ham radio. Many of the
groups have links to frequency sites. A good website for frequency
information for all areas of the country is
M: Are scanners against the law
in some places?
E: Scanner laws vary widely
from state to state. Some states have no restrictions, while others are
quite strict, especially regarding mobile or portable use. Some states
even require a permit. Check if there are laws applicable in your area. A
good radio-related hobby shop should be able to point you in the right
direction. Also ask other area scanner users or your local police
department about laws regarding scanner use. In many states, licensed
amateur radio operators are permitted to have mobile scanners.
If mobile or portable scanners are permitted in your area, be discrete
with their use in public. Strolling through the local mall with the
security channel blasting from your belt is a pretty stupid way to attract
a lot of unwanted attention, especially in this day of heightened
awareness of homeland security. Keep the volume low or consider using
headphones or an earpiece to avoid drawing suspicion in certain places.
M: Are there laws against
listening to certain frequencies?
E: With the exception of
cellular and cordless phone frequencies, and encrypted communications, you
are entitled to receive just about any type of radio signal as the
airwaves are considered a public place. Early
cellular and cordless phone users
believed that their devices were secure. What they didn't realize, and
what the cell phone companies did not tell them, was that they were
actually using radios that transmitted unsecured signals in all
When a high-ranking Washington politician was overheard on a scanner
saying something on his cell phone that later came back to bite him, the
powerful cellular telephone industry association lobbied for the passage
of an anti-monitoring law in the late-1980s. At the time the law was seen
as a serious threat to the scanning hobby. Fortunately, that wasn't the
case. But the result of the law is the reason cellular phone frequencies
are excluded from scanners sold in the United States.
The radio spectrum is for the most part a public place. Two-way radio
users need to remember that they shouldn't say anything over the air that
they wouldn't want anyone to hear, or that they wouldn't want to see as
the top story of a newspaper or newscast.
M: What are ten-codes and what is
E: Back in the early days when
public safety radio frequencies were located just above the AM broadcast
band, police departments used codes for routine messages, partly for
brevity, and partly for some bit of secrecy. "10-4, 10-8,
10-12," and so on. However, it didn't take long
to figure out what they were saying.
Because there is no standard set of codes, using "plain text" or the
actual words to speak your message is favored. This avoids confusion when
two agencies need to communicate with each other and the meanings of their
codes are different.
For example, if a police officer says "10-8 at the 10-20, 10-13" and means
"On scene of an armed bank robbery in progress, send assistance," another
law enforcement agency might translate his message into "Out at my home
for meal break." While that is an extreme example, you can see why plain
text messages are preferred.
M: How many scanners do you
E: I currently own five
scanners. My primary scanners are a
Radio Shack PRO-2067 mobile and a
PRO-92 portable that I keep in my truck. Both are 500-channel analog
trunking scanners that have the same internal workings in different cases.
Both can be cloned with each other; can be programmed through a computer,
and feature an alphanumeric display and tone-coded squelch decoding. In my
computer room/office, I have a RELM (Regency) MS-200 200-channel
computer-programmable conventional mobile unit with alphanumeric display
and tone-coded squelch decoding. In my hobby workshop, I have a Uniden
Bearcat 200-channel conventional scanner with CTCSS decoding only. The
final scanner, currently in reserve status, is a RELM HS-200 portable,
which has tone-coded squelch decoding but no alphanumeric display. I also
have scanning capability in my amateur radios in my truck.
M: What else can scanners
monitor, in addition to emergency radio traffic?
E: Railroads, boats, aircraft,
amateur radio, NASCAR, snowplows, taxi companies, and towing services are
also popular monitoring subjects. In fact, the monitoring possibilities
are almost endless. If radios are used, and you know the frequency, and
the frequency is within your scanner's operating range, you can listen to
M: Do you have a favorite
E: Actually, it hasn't been
invented yet. I've made do with each of the scanners I have owned. But in
each case, I had to make some sacrifices, because no one scanner has had
all the features I want in one package.
M: Do you have a favorite
Strong Signals is a great resource
for questions about scanners and scanning in general. There is a ton of
information there gathered from various sources.
M: And what is your pick for the
best Code 3 release from last year?
E: The Harrison Mack CF pumper.
I love the classic lines of the Mack CF. While both versions were very
attractive, Iíd tip my favor to the all white one. Simple, yet classic
Ed O'Connell can be contacted at
Mike Legeros can be contacted
Both welcome your comments, questions, or corrections.
A version of this column originally appeared at
Code 3 Collectibles.
Copyright 2017 by Michael J. Legeros