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Author Topic: Firepager tones, motorola, and portable ht programming?  (Read 6404 times)
GRANDKODIAK
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Posts: 85




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« on: December 17, 2012, 06:59:23 PM »

I have a Wouxun UV6D that I usually leave in dual channel mode and scan the county dispatch channel on 1 and my fav repeater on the other. Problem is, that its a county line... I'm really only interested in hearing my town's dispatchs... but I am not to familiar with how tones work for the paging system. I gave it a once over on wiki (pretty sure our city uses motorolla monitor system pagers)

it looks like the pagers are just scanners that squelch out until opened by an AUDIO tone (please correct me if I'm wrong, a DTMF maybe?) instead of a continusouly broadcasted subtone like one would use to access a repeater... then stays open for a set number of minutes as programmed then back in standby until the audio tone is heard again. Now I assume repeaters listen for subtones before transmitting in the same way pagers do for opening squelch... is that an accurate comparrison? if so, I'm guessing that my wouxun can be set up to ignore incomming audio unless its the correct tone (making it a fire pager)? Are there any HT hams that have this feature if not?
« Last Edit: December 17, 2012, 07:01:32 PM by GRANDKODIAK » Logged

Tech/General

no base station yet

Yaesu FT-7900r VHF/UHF
Cobra 29LX CB
Wouxun KG-UV6D VHF/UHF
KA4POL
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Posts: 1978




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« Reply #1 on: December 17, 2012, 10:24:39 PM »

Just a guess, it could be DCS tones, i.e. a certain tone sequence being transmitted to open just the accordingly programmed receivers.
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AA4PB
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« Reply #2 on: December 18, 2012, 06:24:24 AM »

If you are hearing two tones, it's probably the old "two tone sequential" paging standard. Your HT probably doesn't have the ability to work with two tone sequential.

Most amateur repeaters use a continuous sub-audible tone. That's a continuous low-frequency tone that is below the audio range of the receiver so that you don't hear it. There are also some newer standards like Digital Coded Squelch (DCS) where a burst of data is sent at the beginning of a transmission in order to open the receiver squelch. That's good for when you have a lot of different "talk groups" on frequency that you might want to selectively activate.
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GRANDKODIAK
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« Reply #3 on: December 18, 2012, 07:05:51 AM »

Yea looks like the Motorolla system is an audible version of CTCSS. I had the idea to set a CTCSS for the first tone to at least block any dispatch that didn't share the same first tone (or second if there were too many) but I forget CTCSS stops at below audio. I found the audio values though if anyones curious... the dispatch uses one frequency but depending on what town they are calling, they send out a 5 second burst of 2 audible tones, the first for 2 seconds, the second for 3 seconds. In my case, my towns first tone is 1232hz and second is 643hz. If you listen to the frequency you will hear the tones, just flat tuning fork type alert noises... but each pager is set so when it hears that signal, it opens the squelch to listen to the frequeny for a set period of time then goes back into mute until it hears those specific notes again. CTCSS only goes from 67hz to 254hz... so my idea of using a single tone open option woudlnt work, and ALSO because its only sent at the beginning of a transmission, and not as a subtone for the duration of the broadcast like with CTCSS... so youd also have to program the CTCSS function in the radio to also open for a set period of time after hearing the tone like a DCS system or this motorola system. I'm guessing though that this is either impossible because they range is present because of the actual hardware that makes up the radio, or is hard programmed into the radio operating software.


buuut theres still hope perhaps that someone somewhere makes a radio that has this feature built in already?
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Tech/General

no base station yet

Yaesu FT-7900r VHF/UHF
Cobra 29LX CB
Wouxun KG-UV6D VHF/UHF
KA4POL
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Posts: 1978




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« Reply #4 on: December 18, 2012, 07:31:29 AM »

so youd also have to program the CTCSS function in the radio to also open for a set period of time after hearing the tone like a DCS system or this motorola system.
The CTCSS must not be on (in receive) to receive DCS. If CTCSS were on, your receiver would not open.
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AA4PB
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« Reply #5 on: December 18, 2012, 08:06:36 AM »

You might find a scanner receiver that includes sequential tone squelch. I doubt that you'll find any ham HTs.
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KB1SKZ
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Posts: 4




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« Reply #6 on: December 18, 2012, 10:11:07 AM »

What you are describing is two-tone decode, originally named (trademarked?) by Motorola as Quick-Call 2 and is now manufacture agnostic.  It has nothing to do with CTCSS or DCS.  I’m not aware of any Amateur equipment that has two-tone decode as a programmable option.  Lots (all?) of Public Safety portable radios have this option.  It should be noted that your use case is a bit non-standard, where you want the dispatch channel silent until “toned” but other channels with normal RX traffic, and doesn’t seem accomplishable.  Usually the radio is entirely silent until toned at which time it remains open (i.e. normal RX) until you press a programmed button that again silences the radio.

Channel scanning also impacts the ability for the radio to RX the first tone in the pair, as you noted the first tone is 2 seconds in length.  If the lookback to the primary channel is delayed and does not completely capture the first tone then the radio decoder will miss the entire set and not alert/open (especially if talking on a secondary channel).

Depending upon how important/interesting the fire traffic is for you, purchasing a fire pager with the frequency and tones is a straightforward solution and is very common in my neck of the woods.  New they are ~$400, used are substantially less but getting it programmed might cause some heartburn.  The reason why I mention this is that with the Jan 1, 2013 deadline for FCC Narrowbanding many fire/ems departments across the country have found money (read: grants) that have allowed fleet refresh for new “narrowband” pagers letting the older ones go.  So long that there is not an immediate frequency adjacency, an older wideband pager will function just fine (about half my fleet – 25 or so – use wideband Moto IV pagers without issue).  I’d find out who does the county fire radio work and give them a ring – they might have this “junk” sitting around. 

As an important side note, there is nothing proprietary with this system that requires you to have Moto gear.  Swissphone makes a very competent pager that uses a standard rechargeable AA battery, very much unlike the Moto V pager.  There are others.

/Jeff
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K5LXP
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« Reply #7 on: December 20, 2012, 06:09:51 AM »

I found the audio values though if anyones curious... the dispatch uses one frequency but depending on what town they are calling, they send out a 5 second burst of 2 audible tones, the first for 2 seconds, the second for 3 seconds.

Sounds like Quik Call II:   http://en.wikipedia.org/wiki/Selective_calling

You could get a commercial radio that has this built-in (you would need to get it programmed).  I have motorola radios that are 25 years old that include quik call.  Plus there's "hardware" options like an old Minitor pager with the right tone modules in it.  You can find that stuff at hamfests and online if you look around.  I recall too there are programs you can run on a PC that use the soundcard to decode the tones.  Wouldn't surprise me if some modern scanners would have it, since they do advanced features like trunking too.


Mark K5LXP
Albuquerque, NM
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WB6DGN
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Posts: 617




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« Reply #8 on: December 24, 2012, 09:47:08 PM »

Quote
What you are describing is two-tone decode, originally named (trademarked?) by Motorola as Quick-Call 2

QCII sounds like two tones sent sequentially but, in reality, there are FOUR tones involved.  Two tones sent simultaneously followed by a second set of two tones, also sent simultaneously.  There are other, more modern, paging schemes such a POCSAG and 5/6 which are slowly replacing the QCII format, mainly because of improved noise immunity.  Search " common paging schemes" for the details.
I doubt that any amateur radio is capable of decoding any of these systems though most commercial handhelds can decode, at least, some of them.  I am not aware of any DTMF based paging system in common use and, certainly not a sub-audible based one for obvious reasons.
Tom
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KT4WO
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« Reply #9 on: December 28, 2012, 01:43:28 PM »

TYT HT's have 2-tone en/de-coding .... I use mine for the local VFD.

Trip - KT4WO

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KT4WO
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« Reply #10 on: December 28, 2012, 01:48:47 PM »

RE:"QCII sounds like two tones sent sequentially but, in reality, there are FOUR tones involved"

Nope,,, You are thinking of QC1 .... QC2 uses  single tones.(so two tones sequentially)

And, at least in my area, all emergency services use QC2.

Trip - KT4WO
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WB6DGN
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« Reply #11 on: January 23, 2013, 02:03:19 AM »

Quote
Nope,,, You are thinking of QC1 .... QC2 uses  single tones.(so two tones sequentially)

Boy!  I didn't think I'd ever forget that.  Yes!  The old QCI boxes that mounted on top of the TwinV radios used FOUR of the old copper "Vibrasponder" type reeds.  Hope its just senility setting in and not something serious!
I've been on a run lately; this is about the fourth post where I've tried to "rewrite history".  Just can't seem to get away with it, though.  You guys are just too sharp!
Tom
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KT4WO
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« Reply #12 on: January 31, 2013, 09:42:09 AM »

Don't feel bad Tom....I'm have those days...more and more often...!!!
haha ...

I program ALOT of Motorola radios so thats why I remembered that.

I didn't know anything about QC1 tho ... before my time I guess...
Thats what they used in LA on the TV show "Emergency" was it not???

Trip - KT4WO

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