Each time a user presses the transmit key to send a message, the computer picks an empty frequency to broadcast on. Through the use of a dedicated computer control frequency that all radios monitor, the computer is able to inform all radios which frequency in the system should be tuned to hear the broadcast.

Since the computer is picking the physical frequency being used and due to other radio traffic on the same system, a single conversation between two users can take place on multiple physical frequencies. Or, in other words, it can "hop around" a lot which can make effective listening using a conventional scanner downright frustrating, if not impossible.

TrunkTrackers are specially programmed to be able to monitor the control data of the radio system so as the conversations move to new frequencies, it tunes the scanner to the appropriate frequency so nothing is missed!

The first TrunkTracker was the handheld BC235XLT followed by the base/mobile BC895XLT. Uniden also took this technology and made the PRO-90, PRO-91, PRO-2050 and PRO-2066 for RadioShack. These TrunkTrackers could only work on Motorola systems in the 800 MHz band. And they could only monitor one such TRS at a time.

The introduction of the BC245XLT TrunkTracker II fixed many of these limitations. Not only could the BC245XLT monitor Motorola Type I, Type II, Hybrid, SMARTNET, and PRIVACY PLUS trunked systems just like the orignal TrunkTrackers, it can also track trunked radio systems made by GE/Ericsson which are commonly called EDACS.

Such systems can now be monitored with the BC245XLT if they are in the VHF, 400, 500, 800 or 900 MHz frequency bands. Other enhancements allow the simultaneous monitoring of multiple trunked radio systems along with conventional frequencies all at the same time!

Uniden took much of the TrunkTracker II technology and incorporated it into the PRO-94, PRO-94A and PRO-2052 which they made for RadioShack.

The BC245XLT TrunkTracker II was another giant leap in technological capabilities. It could track both Motorola and GE/Ericsson (EDACS) systems and it could do so not only on 800 MHz but on VHF, 400, 500 and 900 MHz bands as well! As if that were not enough, it allowed the user to listen to multiple conventional and trunked systems at the same time! Other new advances included the SmartScanner feature, Autolight, cloning and computer interface and control. The BC245XLT also doubled the number of Scan Lists per bank to 10 allowing up to 100 trunking IDs to be programmed to direct listening.

While the BC245XLT could monitor both Motorola and EDACS, the BC780XLT can do this as well as being able to handle LTR (E.F. Johnson) systems! Support for EDACS system has also been augmented by the selection of 4800 or 9600 configurations. A new Control Channel feature allows the user to program only the control channel frequency and then the BC780XLT is able to automatically determine the other frequencies to tune and thereby trunktrack. If a TRS user presses the emergency call button on their radio, the BC780XLT will issue a special alert to notify the listener of this unique situation.

The tuning range is continuous within the specified 25-512 and 806-1300 MHz bands. Memory banks remain at 10 while total memory channels is up to 500. Selectable tuning steps and receive modes (AM, FM & WFM) allow the user to tune just about any desired VHF/UHF signal. There are 10 search bands which can be linked together and auto-store programs frequency activity into memory upon activation. Service Search automatically scans thousands of pre-programmed frequencies for any one of the 10 specified agencies.

Both the large LCD display and keypads are backlit with a selectable dimmer. The LCD supports two lines of programmable text with up to 16 characters per line for help in identifying memory banks, memory channels, search bands and trunking IDs. A mute key allows the audio to be silenced on command. The new Screen Mask feature filters the display so that only the most important pieces of information are seen making the LCD much easier to read in mobile environments. The Beep Alert feature allows any memory channel to be so tagged so that any activity on that channel's frequency results in a series of alert beeps to get the user's attention. A reverse frequency feature allows for the instant reception of a repeater's input or output frequency based on the currently tuned frequency.

Wideband systems are used by both public service and business agencies mainly in the 800 range but a few can be found on VHF/UHF.

Since a trunked radio system is at the mercy of the computer controller, it is beneficial to use the same representation that it does to identify the various agencies found on a system. This is done when the system is first installed and programmed with various numbers which are used to identify different agencies and their different purposes. Such numbers are generally refered to as trunking IDs or talk group IDs.

On a TrunkTracker, you program trunking IDs into the Scan Lists to do the same thing! Find out which IDs you want to listen to and then divide them up into useful groupings (usually by agency). You can then program each grouping into a separate Scan List (the BC780XLT has 10 Scan Lists per bank with each capable of holding 10 IDs).

Most times, the default Fleet Map that the TrunkTracker picks will be good enough to follow most trunked systems. However, older Type I and Hybrid (Type I and II together) systems might not be effectively monitored with this default Fleet Map. You'll know it because you'll see both even and odd IDs on the LCD and you may even miss some replies while trying to follow conversations. If the Fleet Map does not match the system being monitored, the TrunkTracker can't track it 100%.

The BC235XLT would show all these signals with their unique trunking ID assignments so you could see 272 and 273. But the BC245XLT and BC780XLT default to a different approach. They are aware of the the status bits which designate these "special" signals. By doing so, they are able to filter the unique ID and come up with the primary ID. So both the 272 and 273 IDs appear as 272.

To make the BC245XLT or BC780XLT operate like the BC235XLT, which does have its advantages, then the Status Bit function must be turned off. Once this is done, the radio will no longer filter the IDs and all unique IDs will be displayed.

Early model BC235XLTs had this problem which was rectified in later production runs by including the ability to turn off this Disconnect Tone Detect function. All BC245XLTs and BC780XLTs come with this ability.

With this feature disabled, the radio will only leave a transmission when the squelch closes. As such, the squelch might need to be "fine tuned" (with this feature normally enabled the squelch is ignored altogether) for best reception. And you can expect each transmission to have a longer squelch tail due to the delay between the time the squelch closing is detected and the audio is muted.

Encrypted signals are a class of "special" signals which normally use unique IDs. But on the BC780XLT, its default action is to filter such IDs to map them onto their primary assignments. Some users, who were use to seeing two unique IDs on their first generation TrunkTrackers, are now seeing just one ID on their BC780XLTs. It also rules out the ability to block these "special" signals since they are no longer identified with unique IDs.

Luckily, the BC780XLT comes with a feature which allows it to function like the first generation TrunkTrackers by turning the Status Bit function off.

With this feature, it is possible to track a trunked system by only programming the control channels. There is no need to program all of the system channel frequencies which normally includes a few control channel frequencies and a lot of voice channel frequencies.

While it is a great aid for monitoring new systems, it is not a fire-and-forget type feature. To successfully track a system, you also need to know something of the frequencies involved since programming involves the selection of one of four possible frequency schemes. If the wrong frequency scheme is selected when using control channel only mode, the radio will track conversations on other systems or miss them entirely.

On any one EDACS systems, up to 16 agencies (00-15) configured to use the system. Each agency is then divided into fleet of which there can be 16 (00-15) as well. And each fleet can further be divided into 8 subfleets (0-7).

The numeric AFS format is AA-FFS where AA is the agency number (00-15), FF is the fleet number (00-15) and S is the subfleet number (0-7).

This is a feature of the BC780XLT which allows you to tailor the search and scan operations while tracking an EDACS system. It uses the natural heirarchy of the Agency-Fleet-Subfleet (AFS) numbering scheme to do this.

Normally, users are uniquely identified by their full AFS ID. Such IDs are seen in search mode and can be programmed into a Scan List for scanning. But say you know that Agency 04 is programmed for all police units and that's what you want to listen to exclusively. Normally, you'd have to find out what all the unique AFS IDs are for all the police users in this Agency.

With AFS Partial Entry, you simply program the AFS ID by just specifying the Agency. In this case, 04. The radio will now only track transmissions which have 04 as the agency and ignore all others (agencies 00-03 and 05-15).

To further refine this "filtering", you can specify the Agency and Fleet but leave the Subfleet unspecified. The radio will now track transmissions of any Subfleet that match the Agency and Fleet you specified!

How are you to know the ordering? If you're lucky, you'll be able to find a book or web page authored by someone who has already figured it out for you!

If your are on your own, some have speculated that you can monitor the system while in conventional mode to determine the proper frequency order. Try to manually track a single conversation and note the order in which frequencies are used.

Terry was kind enough to donate this Microsoft Excel spreadhseet

A note about the order of frequencies when tracking an LTR system. You need to know the home channel number that is in the subaudible data of each LTR repeater. I was able to use my OptoTrakker LTR decoding from baseband audio of another receiver parked on each frequency to do this. Once you know the channel number, you can then put it into a bank in the same channel number as the subaudable data reported.

The BC780XLT can tune in 5, 7.5 10, 12.5, 25, 50 and 100 kHz step sizes. The radio will automatically select the proper step size based on the receive frequency but you can also override this feature and select any size you wish.

When listening to the repeater frequency, it is possible to use the Reverse Mode feature to temporarily listen to the opposite repeater frequency. This is most useful if you normally listen to the output frequency. If you use the Reverse Mode in this case, the input frequency will be monitored and if a signal is heard, you know that the radio emitting the low-powered signal must be nearby.

CTCSS decoding is done using a search algorithm which, when the target frequency is active, tests roughly two tones per second to try and find a match. Since the BC780XLT supports 38 CTCSS tones, it can take about 19 seconds of signal activity to search for all tones on a target frequency.

DCS decoding is done instantly.

Tone codes can also be programmed into memory channels to open the squelch to hear a signal only if the programmed tone is present on the received signal.

The BC780XLT has the most common US frequencies programmed for the following agencies: Public Safety (police/fire/EMS), Marine, Air, Railroad, News, TV Audio, Family Radio, CB Radio, Ham Radio and Special.

The LCD screen can be roughly broken up into 5 lines of information. The first line is used to display bank or scan list numbers and various feature indicators. The second line displays the trunking mode and channel activity indicators. The third line displays the frequency, receive mode, tone code, trunking ID and S-meter. The fourth and fifth lines display the bank/channel or scan list/trunking ID alpha-tags.

When the Screen Mask is enabled, the second and third lines are NOT displayed.

This backlight can be programmed for normal, dim or no illumination.

But I may be a bit color-blind in this area of the spectrum as I aksed the Mrs. to describe the color and she said "orange". I pointed to the BC89XLT and said "Now that's orange and the BC780 isn't that color." She revised here answer to "melon" which, I guess, is a light orange.

NOTE: It does not prevent use of the E key to enter REMOTE mode.

FIPS codes, as Uniden refers to them, are 6-digit codes assigned by the US federal government with each code designating a certain, geographic location and are usually based on county boundaries.

To ensure that you only receive the SAME weather alert signals targeted for your area, you must program the BC780XLT with the proper FIPS code. You may also elect to program the FIPS codes for neighboring counties as well.

#1 You have set the delay to a negative value (-2, -5 or -10) which tells the scanner to leave the frequency after the elapsed time even if there is an active transmission. Turn off the delay or set it to a positive value (1, 2 or 4).

For more details, see pages 15, 19 and 24 of the BC780XLT Operating Guide.

#2 You have Data Skip turned on and pauses in voice traffic are being deemed an empty carrier by this feature which causes scanning/searching to resume when it shouldn't. Turn off Data Skip.

Visit the Uniden web site to acquire the most recent version of the Smart Scanner software.

Think of the benefits from having a program control your scanner all day while you're at work. It can record audio transmissions and log all frequency and trunking IDs that were used. When you're ready, you can look over the data and see if it's turned up discoveries you haven't made through manual monitoring!

To perform this operation, you'll need two BC780XLTs and an interface cable with a null modem adapter. Both the cable and adapter may be purchased from most large electronic and computer stores. Just be sure to pay attention to the gender of the connections so that all the connections mate properly.

NOTE: I think that step 6 at the bottom of page 37 should really read "Enter a frequency for the trunked system using the keypad and then press E."

NOTE: For better clarity, I think there should be a last step here which indicates that the last 3 steps should be repeated until all trunked frequencies have been programmed.

#2 - Page 68 - Enter Lock - The Enter Lock as described on this page is incorrect. Enabling this feature does NOT disable the keypad. Enabling this feature prevents use of the E key thus disabling the programming of frequencies or trunking IDs into memory. It does NOT keep the E key from controlling REMOTE mode. This feature is correctly described on page 14.

#3 - Page 4 - Frequency Coverage - The "Note" on that pages reads "The frequency coverage is not continuous and excludes the cellular band, 512-806MHz." To avoid confusion, something like this would probably be better: The frequency coverage is not continuous and excludes one of the TV broadcast bands (512-806MHz) and the cellular telephone bands (824-849 and 869-894MHz).

#4 - Alpha-tags - While there are sections in the main part of the manual explaining how to add alpha-tags to memory banks and memory channels (page 21), the instructions for adding them to search banks (buried in a Note on page 28 and in the details of SEARCH BANK on page 18), Scan Lists (in the details of ID LIST TAG on page 17) and IDs (buried in a Note on page 43 and in the details of PROGRAM ID on page 17) is nowhere near as detailed. The text on page 43 for ID alpha-tags directs the user to page 21 which only has details on program memory bank and channel alpha-tags.

#5 - Page 39 - Steps 2 & 3 - MONITOR Mode - These steps indicate that after pressing SCAN to scan a trunked bank and then TRUNK to initiate trunked scanning that this puts the radio in MONITOR mode (where the control channel is heard and active talkgroups will be seen but not heard) and that SRCH must be pressed to start trunked search mode. This is incorrect. As soon as TRUNK is pressed the radio enters trunked search mode. After entering trunked search mode, press TRUNK twice to enable MONITOR mode. The SCAN and SEARCH indicators will NOT be lit but HOLD will be. You will hear the control channel and any active trunking IDs will briefly appear on the top alpha-tag line.

#6 - Page 68 - Screen Mask - Although not mentioned here, when the Screen Mask is enabled, the letters L and M appear in the upper-right hand corner of the LCD. While these letters normally stand for LTR and Motorola trunked systems, in this mode they stand for LCD Mask.

#7 - Page 42 - SELECT Key - As stated, this key toggles between access to the active Banks and active Scan Lists. What is not mentioned are the other aspects of the LCD which are effected by this access when monitoring a trunked bank. If SELECT is pressed to gain access to the active Banks, an active trunking ID will display the Scan List number and ID channel in the upper left corner and the bank alpha-tag on the lower line. If SELECT is used to gain access to the active Scan Lists, an active trunking ID will display the bank number in the upper left corner and the Scan List alpha-tag on the lower line.

#8 - Tone Codes - While the manual explains tone squelch mode, tone search and tone lockout operations (page 31), it is remiss in addressing the setting of tone codes for memory channels (see page 15, TONE DATA) via the Menu system.

• Full 800 MHz coverage (not cell-blocked like US models)
• Different Service Search frequencies
• No weather service SAME/FIPS capabilities
• The front panel WX button is replaced by a Service Search button
• Different default receive modes and tuning steps
• Different reverse frequencies for repeater access
• Uniden's Smart Scanner server download will be useless for non-US users
• Obviously a different AC adapter will be supplied

The antenna you choose will have to take into account the frequency ranges you monitor as well as the type of environment(s) you listen from.

Most discone and beam type models available today do a good job at wide-band receiving but do not do well on a specific frequency range that you might be interested in.

If you live in a rural area, an external antenna will likey be needed for best signal reception. If you live in an urban area, adding a better antenna MIGHT overload the radio and cause it to emit various forms of interference. Some of this type of overload MIGHT be remedied with judicious use of the attenuator feature.

Power jack: 5.5mm outer, 2.1mm inner, positive tip
External speaker jack: 1/8 inch (3.5mm)
Tape recorder jack: RCA
Antenna jack: BNC
RS-232 jack: 9-pin D-shell (DB-9)

Banks: 10
Channels: 500
Scan Lists: 10/bank
Trunking IDs: 10/Scan List
Frequency search lockouts: 200
Service search lockouts: 100
Trunking ID lockouts: 200
FIPS codes: 15
Weather channels: 7

CTCSS Codes: 38
DCS Codes: 104

Scan rate: 100 chan/sec
Search rate: 100/300 steps/sec

2, 4 & 9 - display firmware version and checksum