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What is Trunking?

Trunking describes the ability of a suite of users all sharing a common set of frequencies at the same time. It is very important that you understand the basics of trunking, so that you understand what you program and why. If this is the first time you've run into this topic, it's strongly suggested that you read the Trunking Basics wiki article before reading further. Concentrate on the basics, Motorola and EDACS topics.

Types of Trunking the 245 Will Handle

a. Motorola Analog 800/900 Mhz (Type I, II, IIi)
NOTE: Motorola is phasing out the older Type I and IIi hybrid systems in favor of Project 25 and other systems. As there are fewer and fewer of these systems, this document will concentrate on Type II systems.
b. Motorola UHF
c. Motorola VHF
d. EDACS

Types of Trunking the 245 will not Handle

a. Project 25 systems
b. Several types of EDACS systems, such as:

  1. EDACS Narrowband
  2. OpenSky
  3. ProVoice

c. Logic Trunked Radio or LTR systems; however, you can program these frequencies in a conventional mode and listen

Using the RadioReference DB (RRDB)

The single best source of data for trunking is the RadioReference database. Many older sites, such as Trunktracker.com, Bearcat.com and many others have dated information, and are not nearly as complete. The SmartScanner application as mentioned in the owners manual was a disaster - expensive, wrong data and inconsistent connections doomed it, and has subsequetly been discontinued.
When examining an entry in the database, always pay close attention to the System Voice entry at the top of each entry. Only these voices are trunkable by the 245;

  • Analog
    • These systems are fully trunkable once the programming is correctly established
    • An example of an analog system is shown here
  • Analog and APCO-25 Common Air Interface
    • This indicates that there are some talkgroups on this system that are digital, and these cannot be copied by the 245. However, the analog talkgroups are still copyable. This is a typical Motorola system type.
    • An example of an analog system that has digital audio- a so-called 'Mixed Mode' system is here
  • ProVoice and Analog
    • Similar to the entry above, except this is an EDACS system type.
    • An example of a ProVoice/Analog system is shown here

Additionally, any talkgroup marked with a 'D' (digital) or 'E' (encrypted) in the mode column are not listenable - all you will hear is noise.

Common Programming Steps

Programming a system is relatively straightforward, and once done a couple of times, it's quite likely you will slap yourself on the head and say 'DUH!'. Specific keys are in CAPS and in bold

Programming a system
  • Press TRUNK until the display clears, and the bank list at the top is flashing
  • Press the number of the bank you wish to program
  • Using the HOLD/UP ARROW or LIMIT/DOWN ARROW, select the system type for the bank. These are
    • E2 800 for Motorola Type 2 systems in the 800mhz band
    • E2 900 for Motorola Type 2 systems in the 900mhz band
    • E2 UHF for Motorola UHF systems
    • E2 HI for Motorola VHF systems
    • Ed for EDACS systems
  • Select the correct entry by hitting the ENTER key. The display will blank out.
  • If you are programming a UHF or VHF trunking system, see the topic now for the next steps, then return here.
  • Begin programming all frequencies listed in the database. As you finish one frequency, hit ENTER then HOLD/UP ARROW to get the next slot. If you make in error in keying, you may use LIMIT/DOWN ARROW to go back and correct your mistake.
    • EDACS frequencies must be entered in a special order to properly trunk. This is referred to as the Logical Channel Number. It's shown in the database as a small 2 digit number next to the frequency. Follow this order exactly. Never start programming these frequencies in channel 0 - Always start in channel 1.
  • Once all frequencies are programmed, press TRUNK then SRCH. If your programming was successful, you will start to see talkgroups as defined in the database. You are in ID SEARCH mode as shown on the display. Do NOT hit SCAN yet, as the 245 isn't programmed for it yet. This is similar to what RS/GRE scanners refer to as 'open mode'.
Programming Tips
  • Do NOT skip any channels, especially if they have a raucous motorboating type sound on them. These are the Control Channels for the system, and the scanner MUST hear them clearly to be able to trunk.
  • In the RRDB, Control Channels are listed in red and blue, with an asterisk next to them. Red are primary frequencies, blues are secondary. Programming these frequencies first may result in the scanner acquiring the system somewhat faster.
Programming a Scan List
  • If you want to be able to listen for only certain talkgroups, we need to program the 245 with what is referred to as a 'scan list'. This is somewhat similar to what RS/GRE scanners call 'closed mode'.
  • On the RRDB, ignore the hex notations. These are used for professional radios, and not for scanners.
  • While trunking in your desired bank, hit HOLD/UP ARROW or MAN. The screen should blank out, and a series of underscores (______) should be on the screen
  • Begin entering your talkgroups, in any desired order. As with programming frequencies, you hit ENTER to finish each entry, then HOLD/UP ARROW to get to the next desired slot. The 245 can hold 10 banks of 10 talkgroups apiece. You can correct your errors by using LIMIT/DOWN ARROW to access the ones in error.
    • EDACS talkgroups are usually entered in AFS (Agency Fleet Subfleet) notation - represented by 2 digits, followed by a dash (-), then 3 digits. When entering EDACS talkgroups, use the ATT/. in place of the dash.
  • When all programming is complete, press TRUNK then SCAN. You will then see 'ID SCAN' scroll across the display. The only talkgroups you will see are those in your list.
    • If you see EDACS talkgroups in decimal form, press SVC for 2 seconds while trunking in that bank. It will cause the scanner to revert to AFS display, and remain that way.

Special Steps for VHF/UHF programming

  • In these cases, you must supply a base/offset for the scanner to correctly trunk in these bands. An example of a UHF trunking system is shown here. The base/offset is shown under the Custom Frequency Table
  • After selecting the correct system type, press DATA
  • Enter the base frequency as shown in the RRDB.
  • Press ENTER to enter the base frequency.
  • Press DATA again to enter the offset.
  • Enter the offset as shown in the RRDB.
  • Hit enter to return to entering frequencies

Undocumented Features

  • If the trunk type is Motorola you may enter conventional frequencies in the same bank. However, you cannot do this if the bank is an EDACS type, as the scanner cannot determine that these frequencies do not belong to the system.
  • You cannot program more than 1 system in a bank. Uniden firmware will attempt to capture the first control channel it sees and ignores others, regardless of whether there is more than 1 system in the bank or not.
  • If there are more than 100 talkgroups in your desired list, repeat programming the system in another bank, and continue typing your talkgroups from where you left off
  • If the Motorola system you are monitoring is weak or noisy, you may find that the scanner will lose a conversation too soon. Normally it would listen for a disconnect tone before resuming scanning, but a noisy signal can fool the scanner and cause it to drop the conversation. To avoid this problem, press SVC while scanning in the trunk bank. The SVC symbol will show up on the display with a line through it, and flash 5 times. The scanner will no longer listen for the disconnect tone to drop a conversation. To restore normal function, repeat the procedure.

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