Uniden BC780XLT Mobile/Base Scanner | |
|
|
Uniden BC780XLT Mobile/Base Scanner | |
|
|
|
 Bearcat BC296D Digital Handheld Scanner |
 Bearcat BC796D Digital Mobile/Base Scanner |
 Bearcat BCT8 BearTracker |
This FAQ is maintained by Anthony W. Haukap The current version of this FAQ document can always be found on my website at: While every attempt is made to present accurate data it should be noted that the author makes no guarantee as to the accuracy of any information provided in this document, and is not responsible for any consequences of its use.
If the Uniden BC780XLT TrunkTracker III is your first Trunk Tracker or trunking receiver you might find the Uniden supplied operating guide to be a bit lacking in detail (it doesn’t help matters to have an error in the trunk programming section!). The following guides will provide you with a step-by-step approach to getting your scanner up and running.
The Uniden Bearcat BC780XLT scanner is available for sale in the USA as of December 20, 2000.   Click on photos to enlarge The industry's first APCO 25 digital capable scanner, the Uniden Bearcat BC785D digital scanner has received FCC approval on August 22, 2002. The Uniden Bearcat BC250D handheld received FCC approval on September 27, 2002.   Click on photos to enlarge
Uniden BC780XLT
FCC ID = AMWUB305C Grant Date: 01/14/2002
The final (shipping version) of the Owner's Manual is available at Uniden.com, these files are in Portable Document Format (PDF). A online draft copy of the English language instruction manual is available in Portable Document Format (PDF)* - BC780XLT User Manual. * Adobe Acrobat Reader is required to read PDF files.
The Official eGroups Uniden Bearcat BC780XLT Scanning Radio Users Group is an automatically maintained mailing list dedicated to the distribution of general information, questions, inquiries about the Bearcat BC780XLT scanner and related topics. The following topics will NOT be allowed on the list: advertising or other commercial material, flaming, uncivilized behavior, etc. A subscriber who violates these rules will be permanently dropped from the list. Alternatively, you can send a blank email message to bc-780xlt-subscribe@egroups.com
I have found that the radio will hold a small amount of current when turned off. This could create a problem when making connections to or from the radio to a computer serial port or a line in jack for audio purposes. To avoid any problems when making any kind of connection (including disconnecting) from your BC-780XLT to your computer you should considering doing the following steps:
The reason this procedure is necessary is because the back of the radio is grounded and if you and accidently hit the back of the radio with a connector you will create a short circuit. Furthermore, some people believe that once they have both the radio and computer off it is okay to connect the radio to the computer's serial port - with the Uniden Bearcat 780xlt simply having the radio off is not enough, it must be disconnected from the power source and the stored up power must be drained for the safest connection to your computer.
The Uniden BC895XLT, BC245XLT, BC780XLT and Radio Shack Pro-2052 radios (this list will most likely be updated to include the BC250d and BC785XLT too) can all be controlled remotely by just about any device programmed to communicate over an RS-232C style serial port. Control is accomplished by sending a command (usually just two letters) followed by a carriage return. The radio will respond with OK for okay, NG for no good, or some other usually short message which is also almost always followed by a carriage return. The command set for the radios is very similar but not identical. The most notable differences arise due to the differences in features offered by the radios. This follwoing document details the Uniden Remote Scanner Control Protocol RS-232C command definition. Please note:
The sensitivity testing was performed by Phil Roberts (N2HUC) The test method is simple. Where does the squelch open. Where does it close. What is the average and is it close to 12dB SINAD.
I discovered that VHF HI frequencies sounded better with narrow FM (NFM) on them instead of the default FM. A little louder as well. I checked the bandwidth of NFM vrs FM. I could see that NFM sloped off at +/- 4 KHz. FM slopes off at near +/- 8 KHz. I think this is somewhat close to what commercial specs would demand. On another note, once the squelch is opened, it will hold on to a signal that is much weaker then what it took to open it. This probably is adjustable inside. Here is the most revealing thing I noticed. NFM is more sensitive then FM.
The radio has both a discriminator output and a data slicer output. Since the radio decodes the control channel it needs a data slicer circuit. The slicer output is internal to the radio since the decoding takes place there but you can tap it and bring it outside the radio and into an external decoder. Essentially the slicer circuit can be thought of as a hard limiter applied to the discriminator output, also internal to the radio. The tap points for the discriminator and slicer outputs on the BC780 are shown in the following photos. The Discriminator tap is also marked as "LND8 Data Skip" There are two places where you can tap the slicer output, one is just to the left of the "LND18 WFM S-Meter" label (pin 7 of IC26), the other point has no markings. They both have their individual quirks...
Remove the top cover of the radio. This will expose the bottom of the circuit board where you can get at the necessary points. The discriminator output is 1 volt peak-to-peak centered on a 1 volt bias. The slicer output is 3.2 volts peak-to-peak centered on 1.6 volts ie. 0 to 3.5 volts swing (TTL compatible).
The most common way to accomplish this mod is to mount 2 RCA jacks for the outputs on the rear panel of the radio. Be sure to label them appropriately! The following MS-Word Document contains the rear panel labels you'll need in the correct size for this purpose. Then run a single wire from the jack through the open space to the top side of the PC board. The slicer output could also be run to pin-6 (DSR) on the DB9 connector that is already attached to the main PC board - this would eliminate the 2nd RCA jack, and make radio control and slicer available through the same COM port and DB-9 interface cable. The slicer data signal should go to the computer's DB9 COM port either pin 6 (DSR) or pin 8 (CTS). Alternatively, if you don't use the cable for computer control, you can tie pins 6 & 8 together, so that the signal is present on both pins at all times. Note that these pin numbers will be different if your computer uses a 25 pin serial connector. What is this used for? The discriminator output can be used to decode digital signals (ie. Trunking control channels, CTCSS Tones, SCA, FSK, RTTY, FAX, etc.) these signals can't be taken directly from the TAPE REC jacks, headphone jacks, or EXT SPEAKER jacks because of the voice-band filtering that is done between the signal source and these output jacks. If you tap the internal data slicer you can run it to your PC's serial port without having an external data slicer -- however the use of some sort of buffer is recommended; For the data slicer this can be in the form of a (value isn't critical) 1K resistor inline with the wire from the tap point to protect the scanner circuit against shorting the line to ground. For the discriminator output connect the positive (+) leg of a (value isn't critical) 1.0-uF to 4.7-uF tantalum capacitor (a ceramic capacitor will also work) inline with the discriminator output pin.
To get the BC780xlt Trunk Tracker III to acquire the data channels faster, put the data channel (a.k.a. Control Channel) frequencies into the first few channel positions of that bank.
The 780xlt is sensitive to 'Lock-Outs' during Trunk Mode. However its sensitivity to it, only extends to the Data-Channel (a.k.a. Control Channel) Frequency. So to increase the speed to acquire (or reacquire) the Data-Channel, every voice Trunk channel in the bank can be locked-out, except (of course) for the current data-channel(s). Please note, during Trunk mode, when the scanner is scanning conventional channels, it will NOT scan the 'Trunked' channels, even if those frequencies are left 'Unlocked.'
The Data Skip feature is designed for use particularly when you are searching a range of frequencies that includes paging broadcasts (such as those found in the 152-153, 158-159, and 454-455 MHz ranges). Since most people will not scan a paging channel or search a range with pagers (who wants to listen to annoying, incoherent tones?), it’s best to simply turn Data Skip off. With Data Skip on, you will occasionally find that transmissions will suddenly drop and the scanner will resume scanning when it actually should be holding on a channel. Data Skip will at times determine a sound, or lack of sound, is part of a paging transmission and will force the scanner to resume scanning or searching. Simply by turning Data Skip off you will avoid this nuisance.
To turn Data Skip off, go into the System Menu, scroll down to Data Skip, select it, and then select off.
You can set the scanner up to alert you when it receives the emergency activation notification signal that is used with Motorola type system. First, you'll need to turn STATUS BIT off, then enter a TalkGroup ID of +2 (e.g. if the ID you want is 80, enter 82) and turn on BEEP ALERT for that ID. Motorola Type II Special Status Bits (status bit signaling) that can be added to the main Talk Group ID: ID+0 = Normal Talkgroup ID+1 = ATG (All Talk Group, a Type II "fleetwide" mode) ID+2 = Emergency Talkgroup ID+3 = Crosspatched Talkgroup (talkgroup patch to another Talkgroup) ID+4 = Emergency Crosspatch Talkgroup ID+5 = Emergency Multi-Select Talkgroup ID+6 = Emergency Mulit-Group Talkgroup ID+7 = Multi-Select Talkgroup (dispatcher simulcast) ID+8 = DES Talkgroup (digital encryption) ID+9 = DES ATG (All Talk Group, a Type II "fleetwide" mode) ID+10 = Emergency DES Talkgroup ID+11 = Crosspatched DES Talkgroup ID+12 = DES Emergency Crosspatch ID+13 = DES Emergency Multi-Select ID+14 = DES Emergency Muli-Group ID+15 = Multi-Select DES Talkgroup
In a Scan-List Entry save the following: Decimal + 0, then press E (Enter key). You have just saved i00000. Now when you are ID Scanning and you have the correct Scan-List selected, you will hear a current I-Call on the system. Even when you manually stop on this ID, you will hear all I-Call traffic.
How to reduce Adjacent Channel Interference:
Bandwidth of NFM, FM & WFM modes:
The documentation at the FCC site lists the IF frequencies as:
1st IF
2nd IF:
3rd IF:
The squelch control has to be the most misused and misunderstood control on the scanner. The way to properly set this control is first set the volume control to minimum and then turn the squelch control to its maximum setting. Next turn up the volume until you hear nothing but static on a channel where nobody is transmitting at the time, then slowly turn the squelch control down just until the static goes away. You may need to slightly adjust the squelch down from this point to keep noisy transmissions to a minimum. If you are only monitoring a trunked radio system, trunked systems use a disconnect tone and do not rely on the squelch control, thus you can set the squelch fully open - this trick will not work if you have any conventional frequencies programmed in the bank that either are not locked-out or do not have a PL/DPL set.
Thanks to Phil Roberts (N2HUC) for this tip. Squelch Modification to eliminate different threshold settings between VHF/UHF - RT-3 is the internal adjustment for NFM and RT-7 is for standard FM, these can be reached by removing the bottom cover. Update - June 2002: Bob Mason tells me that "Uniden [has] corrected the squelch threshold problems between UHF and VHF. On the box, it now says "Copyright 2002" Uniden America Corporation... It is also interesting to note that Uniden has changed the way the put the serial number on the back of the unit. The date code is now in with the serial number. The serial number now says 305C260000065. This would mean that this scanner was made on March 5, 2002... they now ship the unit with a protective piece of plastic that you would pull off the LCD screen. This protects it from scratches during shipping."
I have found out that while knob-twisting to set your alpha tags, you can at least use the keypad for entering numerals 0-9, and the period. This speeds up things a little bit, anyway. I've also found that the . (period) key is a quick way to get to other misc punctuation symbols (hit . and turn the knob left) or back to capital-A (turn the knob right). There is a question-mark (?) available by software control, but not on the 780's keypad
This mod appears here courtsey of Bernard J. Parker (K5BP) Bearcat 780 xlt Squelch Modification. If you have been in two way or are a Ham operator like me, one of the first things you will notice is the BC 780 Squelch control operation is backwards from 99 % of the other radio equipment out there. On most equipment you rotate the Squelch control CW (clockwise) to mute audio. The BC780 is opposite, you rotate the Squelch control CCW (counter-clockwise) to mute, backwards to me! Normally, to change this on a older type unit one swaps two wires on the Squelch pot. The Bearcat 780 has made this more difficult but not impossible. It involves cutting a printed circuit Board trace and jumpering two printed circuit lands. I will give the usual caution. Try this at your own risk, you can blow up your unit and void the warranty if you don't know what you're doing. So, if you are not comfortable with this don't do it, or get competent tech help. First, disconnect power cube from unit. Then turn on unit to discharge any remaining voltage. Next remove 4 screws holding the bottom cover of the unit. Remove cover being careful to unplug speaker wire connector located at the rear of the unit on circuit board. This will free bottom cover to set aside. Starting with the volume knob pull it straight out and off, do the the same with the squelch knob. Remove the nut holding the vol/squelch pot. Unplug the white 8 pin connector on the RH side of the unit (belly up view) same side and nearest "IC3" marking on pc board. You then want to clip off the wire tie. This will allow complete removal of vol/squelch pot. You will notice a small pc board attached to the pot. This is where we will do the modification. Orient the board with the foil side visible and the control shaft up. You will see a pattern of solder lands represented by "O"'s in my crude Fig 1. These are the points where the control has been soldered to board.
| | << Control Shaft
| |
| |
| |
| |
|----------------- |
| O O-O O | <<<< Here is the area we are concerned with
FIG 1. | O |
| O O O O | Note "pins" 1 and 2 jumper with foil trace
| O |
| O |
| O |
| O O O |
| O |
|------------------|
Pay close attention to the horizontal group of 3 solder joints nearest the top of the pc board nearest the shaft. These are terminals for the squelch pot. If we number those joints 1 2 and 3 from left to right as in FIG 2. you will notice that "joints" 1 and 2 are connected by a foil pc trace. I represented that with a dash. You will need to carefully cut the trace between 1 and 2 with a X-acto type knife. Verify NO continuity with a meter if possible. I recommend cleaning the cut area with alcohol and, while still damp, holding the board up to strong light to make sure the trace is completely cut. It is imperative that the connection between "1" and "2" is completely cut open. Otherwise, the squelch function will be inoperative. Now using a short wire lead, jumper "2" and "3" and solder. You may be able to just solder "blob" them together. See Fig 3.
| | << Control Shaft
| |
| |
| |
| |
|------------------|
| O 1-- 2 3 | <<<< Here is the area we are concerned with
FIG 2. | O |
| O O O O | Note "pins" 1 and 2 jumpered with foil trace
| O |
| O |
| O |
| O O O |
| O |
|------------------|
| | << Control Shaft
| |
| |
| |
| |
|------------------|
| O 1 2--3 | <<<< Here is the area we are concerned with
FIG 3. | O |
| O O O O | Jumper "pins" 2 and 3 with short lead
| O |
| O |
| O |
| O O O |
| O |
|------------------|
You are now done with the mod!!! Simply reassemble unit in reverse order of disassembly. Be careful not to over tighten the nut holding the vol/squelch control in the front panel, it is plastic. Remember to plug in the connectors and replace the wire tie if you removed it. Enjoy your normal squelch. This mod was successfully done on my unit S.N. 1600XXXX.
This mod appears here courtsey of J.T. Makatura (N0SGQ) Audio Modification for increased volume - First take off the bottom cover; second fix the rubber speaker gasket. Remove the speaker and cut the center "bar" section out of the rubber gasket and then reinstall the gasket. If the case doesn't seem to fit upon reassembly you have to slightly reposition the gasket under the rear facing section of the speaker. Finally, there is a large 18 ohm 2 watt power resistor next to where the speaker plugs into the circuit board. It is marked R413. This resistor must be shorted to restore full audio through the internal speaker. You can just solder a wire across the terminals or just remove the resistor and install a jumper wire in it's place. You'll be amazed at the difference! What's really amazing is the fact that Uniden loaded a four ohm 5 watt audio output with nearly 30 ohms. Update: February 9, 2003 - JT Makatura reports that this mod also works on the BC785D.
By looking at the schematics available from the net, I'm pretty sure the pots work like this: RT-1 = S-meter NFM/FM RT-2 = Squelch WFM RT-3 = Squelch NFM RT-4 = S-meter WFM RT-5 = Tonedecode frequency for the wheather alert RT-6 = Frequency for reference oscillator for PLL and 3rd mixer RT-7 = Squelch FM RT-8 = Tune voltage for the 108-137MHz filter RT-9 = Tune voltage for the 137-174MHz filter The S-meter adjustments will change the bargraph on the display, but will also change the RSSI values being sent to PC programs that display that kind of information. What squelch pots do are obvious. The wheather alert system sends out some alert tone for a few seconds and RT-5 adjust the frequency of the decoder to detected the tone properly. RT-6 adjusts the receive frequency of the whole scanner. RT-8 and RT-9 are adjusted for maximum sensitivity in its frequency band. "Ubbe" Urban Larsson
This mod appears here courtsey of Steve Donnell (WA1YKL) However, as others have asked about optimizing the contrast setting previously, here goes FWIW. There is no variable contrast control in the 780, however, on the display board, near the middle, you will see an 8.3K ohm resistor, marked "832". Changing this resistor will affect the display contrast. The optimum range seems to be about from, 7.5K to 10K. It’s a fairly narrow range, so its easy to see why some displays may be a bit off peak. Remove the 8.3K and replace it w/ a variable trimpot of say, 5K, with a 5 to 6 K in series. Be sure to anchor down the new configuration or you can expect it to come loose from vibration.
It has been said that... "The signal meter appears to have little relation to the signal strength when in normal use." Wayne R. Suite has posted the procedure to calibrate the S-meter: http://groups.yahoo.com/group/BC780XLTCorner/message/51 Before dong any adjustments also read this posting by Urban "Ubbe" Larsson: http://groups.yahoo.com/group/BC780XLTCorner/message/99 Please note: The adjustment procedure for the S-Meter that was available is evidently gone because the BC780XLTCorner Yahoo group has been removed! As soon as I find the messages I’ll repost the procedure here. Update - August 2002: Here are the messages as they originally appeared on the former BC780XLTCorner group:
In the March 2002 Scanning USA Magazine (they sell back issues!) there is a 4-page article devoted to a modification for unblocking the blocked 800 MHZ ranges of the BC780XLT Scanner. It has step by step instructions, along with photos and diagrams. NOTE: While this mod has become known as the "Cell Mod" is it better called the "Virtual Down Conversion Mod" as it can be used to receive other frequency ranges that the BC780 doesn't cover. Basically the mod requires that you install a DPDT switch to manually turn ON the 800 MHz bandpass filter, and turn OFF the UHF band filter. Thus allowing you to receive the 869-894 MHz frequencies (IF images) in the 381.100 to 406.100 MHz portion of the spectrum. These bandpass filters are usually covered with epoxy to prevent this kind of tampering, however on the BC780xlt these points can be access on the "other" side (not the component side, but the OTHER side!) of the PC board. With the switch in the "de-select" position, the scanner functions normally. For more information and how to order back issues see their web page at http://www.scanningusa.com or you can contact them through the following address:
P.O. Box 9580 Naperville, Il 60567 Voice: 1-800-651-0922 Fax: 630-896-8026 Email: scanusa@compuserve.com
The radio needs SOME way to determine whether or not the control channel has changed. The way Uniden picked was to assume that if there is no activity on the trunked system (i.e. no channel assignments being made) for about a ten second period, the scanner assumes then that the control channel may have changed. Therefore, it (wrongly thinks that it) must find a new one. It will step through ALL UNLOCKED trunked frequencies in the active bank, checking the previously active control channel frequency LAST, regardless of it’s position in the bank - it should always START looking with the last active control channel frequency FIRST, just in case it was radio fade or in a tunnel or other obstacle. Most of the time that is more probable than a control channel change! Workaround #1 - Quicker data channel lockup; Lockout all voice trunked channels in the active bank, EXCEPT those channel(s) that are used as data channels, this will speed up the process of reacquiring the data channel.
With the unit powered off, hold down the [2], [9], & the [Manual] keys at the same time while turning the unit on. This will erase everything - a.k.a. Full Reset.
To find out which firmware version you scanner has - hold down the following key combinations while turning on the 780XLT unit. [2], [4] & [9] will display the firmware version and checksum numbers. BC780XLTThe initial firmware version is 1.19, checksum 8d 1AH. Firmware version 1.20 was issued around May 2002 and removes all references to Uniden's SmartScanner frequency download service. The firmware was updated in July 2002 to version 2.06 - changes? UBC780XLT The initial firmware version is 1.01, checksum FCd 0H.
To load the Test Data hold down the following key combinations while turning on the BC780XLT unit. [2], [E] and [Man] keys - NOTE: this will replace ALL existing data in your scanner. Also holding [2], [9], & [Scan] will load test data.
Choosing the correct Motorola Control Channel Only Mode frequency plan. You must choose one of the 4 frequency plans before you begin to Control Channel Trunk. Note the default PLAN-1 is the most common. Read the description of the plans below for details on which may apply for you.
Scanner Recorder (Scanrec) is a free audio recorder that is primarily designed to record speech. It has a VOX control that allows the user to save disk space when no sound is present in the signal. Here's an explanation on what Scanner Recorder does:
Scanner Recorder is written by Dave Jacobs and you can download your copy of Scanner Recorder from his webpage or by clicking here...
While not terribly convenient, you can program frequencies without using the [.] (decimal point) and without trailing zeros; [0], [1], [2], [3], [4], [E] will result in 123.400MHz being entered.
Mike Krueger, N6MIK posted to the BC780xlt mailing list a method of getting your scanner online, and even controlling it over the internet! Basically you will need...
Regarding the Senss BC245xlt interface control program, it is written for the Uniden Bearcat-245XLT (300-channels) and not the Undien Bearcat-780XLT (500-channels) and Mike notes that; "Most of the functions work, however it appears that some data corruption occurs (in the BC780xlt) if you try to "direct enter" a frequency or talk group. This issue does not affect the operation of the scanner, however when you download into a remote programmer, most of the data is "offset" by one or two digits, making it unusable by WinScan and/or other programs. This is not scientific evidence, but something I'd noticed on a couple of occasions." It should be noted that I have used the Senss BC245xlt program in this configuration, and if you only use it for display purposes it works great, just as advertised. The only time data corruption might occur is when you try to enter a frequency or talkgroup. The Media Encoder "Wizard" is pretty good, and should get your scanner streaming audio online pretty quick so I won't go into detail about that. You can confirm streaming by opening the "Internet URL" in the connections tab in Windows Media Player. For what it's worth, I use the speaker out jack to feed audio into the PC, as I didn't want to reprogram all channels to "record ON". Keep the BC780 volume low to avoid distortion.
Senss' freeware includes two applications. Run BC245INT.exe on the host PC. The setup is very straightforward. Set the baud rate to match your BC780xlt in the setup menu, and enable "Listen" or "Auto-Listen" under Options - TCP/IP. The Remote Status window should now say "Application now listen to remote user". This completes the host PC setup. You are now streaming the audio, and "listening for a user"! At the remote PC, run Listen.exe, the other application in the Senss package. To connect to the scanner, click on the computer icon to the right of the TRNK key and enter your host computer's IP address. The port setting should match your host. The default of 1025 works fine. When you are connected, you'll see the frequencies racing by in the window. Start windows media player and Open the "Internet URL". Within a few seconds, you should hear audio. There is a slight lag in the arrival of audio vs. Listen's frequency display.
Preprogrammed Service (SVC) Search - Allows you to toggle through preprogrammed plublic safety, news media, TV broadcast audio, Ham, CD, FRS, special low power, railroad, marine, and weather frequencies.
The railroads of North America are assigned a group of 97 frequencies within the VHF-HI band. These frequencies are in the range of 160.110 MHz to 161.565 MHz, in 15 kHz increments. The frequency assignments within this frequency range is overseen by the Association of American Railroads (AAR), an industry association comprised of the various railroads of the United States and Canada.
Because of the way in which the BC780xlt operates, some internal generated signals inherent in the electronics of the receiver are generated which may interfere with reception of some frequencies. These interferences are called ‘birdies.’ If your scanner stops during search mode and no sound is heard, it may be receiving a birdie. You must press the search button to continue searching. Sometimes it is possible to set the search limits to avoid these frequencies. Following is a list of frequencies which may be difficult or impossible to receive on the Bearcat 780xlt. If programmed with one of these frequencies, the receiver may be noisy on that channel or stop on that channel when no signal is present. The degree to which your radio will be affected will vary depending on your location, the antenna you are using, and the other equipment operating nearby. If the interference is not severe, it may be possible to adjust the squelch control to eliminate the problem without excluding the desired communication.
NOTE: The birdies your particular scanner receives may differ from those listed here.
CTCSS/DCS is only used by stations using conventional FM frequency assignments. The original purpose was to allow the sharing of frequencies by more than one fleet - each having their own subaudible tone. Fleets hear only units with their own subaudible tone, and fleets using other tones on the same frequency are not heard. This technology is not used on AM services or in WFM mode. Trunking systems use digital squelch, and do not carry CTCSS/DCS tones. The BC780 merely provides this feature in the modes where it is used, and not in those modes where it is not used in actual practice. The most common use of these tones is NOT for two agencies in the same town to share a frequency, but for different towns within each other's reception range to share one frequency. In tone squelch mode, if you set a CTCSS (Continuous Tone Controlled Signaling System or Continuous Tone Coded Squelch System - analog) or DCS (Digitally Controlled Squelch - digital) subaudible tone for a frequency, the scanner will only stop on that frequency if the transmission includes the prescribed tone. You can also lock a tone assigned to a frequency. By doing this you will receive all transmission on the frequency, regardless of the subaudible tone, except the one which you have locked - any transmissions with that locked-out tone will not be received. You can search for any subaudible tone that is being used on a traqnsmitted frequency (non-truked) by placing the squelch mode into Tone Search. The scanner will check each CTCSS t | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
