One very nice feature of the PSR600 which the Uniden scanners cannot match is the ability to decode
CTCSS/DCS and P25 during searches at the same time. With the Uniden it’s one or the other, but not both.
Trunking
Like all digital scanners these days, the PSR600 can monitor several types of trunking. The most common
are Motorola (3600 baud data channels), APCO25 (9600 baud data channels), EDACS Wide and EDACS
Narrow and LTR.
Many wide are statewide and regional systems are coming online that use either the APCO P25 protocol or
variants of the analog Motorola trunking format. These systems have several to hundreds of cells (called
“Sites”) that are all interconnected and share the same Talkgroup and user lists. While on Uniden radios
you would program each Site separately as part of a larger System, the GRE takes a different tack. You
program in the known Control Channels in “MultiSite Roam” mode and the radio will lock onto strong
signals. When the decode quality is reduced to a certain level the radio will automatically rescan to look for
stronger signals. In contrast the Uniden method has users program individual sites and allows one to turn
on and off each Site, either manually, by Quick Keys or GPS.
The GRE method of MultiSite Trunking requires no user intervention, just the active control channels need
to be programmed into the radio. If you want to you can still program different sites into separate trunked
systems. You are however limited to a maximum of 28 channels for the system, if there are more than that
you need to decide what channels to use or duplicate the system with the additional channels. The Uniden
method requires extra programming steps but allows you to program Site names so you can tell what site is
active.
The GRE also supports several flavors of standard Motorola and EDACS trunking as well as LTR.
Motorola modes (in addition to multi-site SmartZone and P25 systems described above) include older Type
I, Type II and Type IIi modes (both with analog or digital modulation). Both the Wide and Narrow modes
of EDACS systems are supported. No scanner can decode EDACS Provoice or Aegis used in selected areas
such as San Antonio and some others.
LTR, very popular on UHF and 800 business systems, is supported along with a neat feature called LTR
Home Repeater AutoMove. While the name is clunky, the feature is not. LTR systems are difficult to
program since they rely on knowing the channel order or position within the system. LTR Home Repeater
AutoMove, when enabled, allows you to program in the system’s frequencies without regard as to the order
and the radio automatically determines the proper positioning.
The basic method of programming a Trunked radio system in the GRE radio is pretty simple. Following the
instructions in the manual, enter the frequencies and other parameters as a TSYS (Trunked System). Then
program in Talkgroups pointing to the TSYS as part of Scan Lists. You can also program in a search of a
TSYS by use of the “Wild Card” option. This works in a similar fashion to Uniden’s Trunked Search
feature in that it allows one to listen to all active Talkgroups instead of just the ones in a Scan List. You can
lockout talkgroups as they become active and you no longer wish to monitor them.
When programming various types of trunked systems you need to know some of the basic information
about these systems. This information varies somewhat depending on the type of system. For many
Motorola and P25 systems all you really need are the Control Channels and system type. For rebanded 800,
most UHF and VHF systems as well as some odd 800 and 900 Motorola or P25 systems you may also need
further parameters, such as base channels, offsets or other technical details. For EDACS and LTR systems
each of the frequencies used as well as the order in which they are programmed are needed.
Most of the information needed for individual trunked systems is freely available on the
RadioReference.com website, paid members can even program the systems directly into their radios using
software such as ARC500. Thus, if you are not a scanner expert capable of figuring out technical details of
complex trunked radio systems you can share in the work of the rest of the scanner community to program
your radio.
