"Tick" heard

[lep]

Using Close Call on a BCD 996 I have come across a 451.9875 station dispaching local bus service that sends a "tick" pulse every few seconds when there is NO voice traffic. On my HP-1 using RF plot today (being a holiday there is no local service) I can see the ticks on the output, there does not seem to be any non-voice on the input. I assume it is (a) to show the channel is available and not occupied or (to discourage scanning monitoring. What type system is this? Is there any setting which will ignore the ticks and still allow normal scanning of the channel? [as they say, Inquring Minds want to know]

 

[quarterwave]

Using Close Call on a BCD 996 I have come across a 451.9875 station dispaching local bus service that sends a "tick" pulse every few seconds when there is NO voice traffic. On my HP-1 using RF plot today (being a holiday there is no local service) I can see the ticks on the output, there does not seem to be any non-voice on the input. I assume it is (a) to show the channel is available and not occupied or (to discourage scanning monitoring. What type system is this? Is there any setting which will ignore the ticks and still allow normal scanning of the channel? [as they say, Inquring Minds want to know]

LTR. Check the license and find the others associated with it, then you can setup an LTR system and monitor it all when the system changes channels.

 

[captclint]

Using Close Call on a BCD 996 I have come across a 451.9875 station dispaching local bus service that sends a "tick" pulse every few seconds

Mapping an LTR System Once you have it mapped and set up, the ticking noise will go away.

 

[lep]

The system in question does appear to be LTR with 5 frequencies in the license which was a little difficult to locate in FCC ULS and only granted in 2013. Gave me a chance to practice my CW by copying the Call so far nothing has been heard except on the frequency I post initially..

Thanks for the help!

 

[quarterwave]

It's possible it has less than 5, we have a UHF here with 3.

I got to thinking, our hospital has a conventional VHF repeater system, and not constantly like you heard, but when certain radios unkey it sends a little squawk of some sort. It's not MDC or DTMF, and not all of their radios. I recently discovered the one guy is a Volunteer and apparently uses his work radio for the VFD, as he was on that repeater on night (recognized the voice) and his radio squawked the same way.

 

[lep]

I printed out a copy of the FCC license and it defintely shows 5 frequencies and station type as FB8. According to the wiki article cited by captclint, those are hallmarks of a UHF LTR system.

 

[loumaag]

Attn: lep

Do not hijack other peoples threads with off topic questions of your own. I moved your off topic question and all responses to it to its own thread.

 

[mikegilbert]

The system could also be LTR Passport, which isn't trackable with any scanner. You can monitor in conventional mode, but not track individual conversations.

 

[lep]

In addition to the 996 close call which told me in the first place that this system existed, I have an HP-1 into which I put a "dumm" listing in order to use the LCN Finder function. It has seemingly noted LCN numbers on 3 of the frequencies but I am still investigating. I hope your sugestion in wrong of course!

 

[GTR8000]

While you're at it, see if you can determine what talkgroup ID is used for the GSU Buses. The TGID should show up on the 996 if you create a custom search for 451.9875-451.9875 with C-Ch Only enabled. Whenever they transmit it should show X-XX-XXX for the talkgroup ID if it's Standard LTR.

 

[W8RMH]

certain radios unkey it sends a little squawk of some sort.

Those radios are transmitting their radio ID number.

 

[lep]

I just logged [0-01-008] but it was a weak user, did not seem to be a bus. First time I have heard this.

 

[GTR8000]

Each talkgroup is "Homed" to a specific repeater. The talkgroup ID will have the Home repeater noted in it, which will match that frequency's LCN. For example, 0-04-001 will indicate that talkgroup is homed to LCN 04. This may help you figure out or confirm the LCN's for that system, especially during periods of light activity when the talkgroups remain on their Home repeater/frequency.

During periods of a lot of system activity, any talkgroup can operate on any LCN, but it's definitely a good start to note what talkgroups are coming up on what frequencies the most often, then compare the x-XX-xxx (capital XX's) to the frequency and LCN.

 

[lep]

TGs logged are: 0-01- 002: 0-01-004: 0-01-007: 0-01-008: 0-01-009. But also noted was 0-07-212.

Since there are only 5 freqs on the license, I assume either I do not understand or this a False.

I entered the 5 freqs on license WPMP580 in order into my HP-1 and activated LCN FINDER.

After 24 hours only two channels had 'ID hits':

LCN 1= 451.7875. LCN 20 = 451.9875

None of the other channels seem identified if I undesand the meaning from the Uniden Manual. [the other channels just have the row of white rectangles with None singled out.

Anyone have a suggestion for a next step?

 

[GTR8000]

LTR systems often skip LCN's, so it could be 01, 03, 05, 07, 09. They don't have to be in any order, it could be completely random. I've seen systems where the LCN's were 01, 04, 05, 07 and the frequencies were all over the place as far as trying to make sense of any numerical sorting from lowest to highest.

It seems clear that you've determined that 451.7875 is LCN 01, which is the repeater all of those 0-01-xxx talkgroups are homed to. That's definitely a good start.

0-07-212 is not necessarily a false hit, as noted above there could very well be an LCN 07 if they're using the odd numbers for them, skipping the even numbers. That's actually pretty common practice for LTR systems.

 

[lep]

Thanks for the useful information. With some separate receivers I have deterlmined that when ther is no apparent voice traffic I always hear the 'idling tick' on three of the five frequencies on the license. Namely:

451.7875: 451.8875: 451.9875 [of course the tick is sometimes suppressed by voice traffic]

452.2625 and 452.3625 - do NOt have a tick nor has voice traffic been heard in my monitoring so far

I am unsure what to make of this...does that mean those are part of the LCN plan or ???

 

[captclint]

452.2625 and 452.3625 - do NOt have a tick nor has voice traffic been heard in my monitoring so far

Quite often, there are conventional frequencies in use on LTR systems. It is also possible that those freq's have not be activated, but it is more likely that they are conventional. If you hear the call sign on them, the lack of a tick is an even better indication. Either way, they are not part of the current LTR system.

 

[lep]

RE: 452.2625 & 452.3625. In a 24 hr monitoring period no 'tick', no voice traffic, no CW ID, nothing at all heard on these two freqs.

These two freqs, like the other 3 with a active 'tick' and voice traffic are licensed as type FB8 in Statesboro, GA. Some voice traffic seems to be bus/taxi service at the Westin hotel, nearest such hotel is 60 miles away in Savannah/Hilton head SC. Bigbie Electronics owns numerous systems with separate sites/freq/calls etc throughout the coastal area.

Of the active freqs : 451.7875, believed to be LCN 1.

One TG was noted as: 0-07-212, all other noted have 0-01-xxx designations.

Is it reasonable that LCN 7 is either: 451.8875 <or> 451.9875, the other 2 'tick' channels?

 

[captclint]

Is it reasonable that LCN 7 is either: 451.8875 <or> 451.9875, the other 2 'tick' channels?

You would need a few more LCN 7 hits to be more sure. If the other are relatively inactive, it is less likely that they would have sent Home channel 07 units to LCN1. Could be an error TGID.
Not familiar with HP-1 auto find feature operates, but you might want to add the other 2 as conventional to see if there is any activity.

 

[lep]

but you might want to add the other 2 as conventional to see if there is any activity.

THe HP-1 has not been able to ID the LCNs probably because I am not clever enough to program the needed dummy info.

However, the lack of activity on the other 2 freqs mentioned has been verified with a receiver 'parked' on those two channels. I have a variety of recievers availalbe to monitor freq of interest to me and no 'tick's or voice traffic has been heard on those in 48 hours.

I am scanning the other 3, they all have 'ticks' and some voice on all but most frequent voice is on a single one, 451.9875