Cambria County tone outs
- Thread starter dal1983
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@druhe? Seeing how you helped the OP of this thread...
What are you looking for specifically ?
Richland FD
A Tone 584.8
B Tone 1122.5
East Hills EMS
A Tone 330.5
B Tone 1006.9
A Tone 584.8
B Tone 1122.5
East Hills EMS
A Tone 330.5
B Tone 1006.9
Cambria County, Pennsylvania (PA) Scanner Frequencies and Radio Frequency Reference
Scanner Frequencies and Radio Frequency Reference for Cambria County, Pennsylvania (PA)
www.radioreference.com
Synapt
Member
A notable mention, the tones being used over 800Mhz are /not/ the same as the tones over UHF. I don't understand why (they claim 'technical reasons' that don't make sense) but they're using slightly separate two-tone pairs for the tones over 800MHz.
It has to do with the p25 signal on how the tones come over.
Synapt
Member
I know in older days (I'm talking like 2005 when I was working in radio infrastructure stuff) there were issues with the digital modulation to utilizing the tones since so much of the digital system was built around voice clarity primarily, but as far as I recall that was long resolved when DTS was introduced. The specification shares the same tone pairing if not more precise pairing as Two-Tone signaling I thought? I know the single-tone model can go down to precision of 0.1Hz, so it would be weird to me if the two tone system didn't as well.
I would double check our code plugs but it appears, despite it being a requirement for radios we bought ourselves (though we got Vikings for our extra radios, not APXs), that Cambria did not include two-tones in the county issued radios, only single-tone lol.
The handling of tones in p25 is inherently limited by the bandwidth (and there for the stability) of the vocoder that was designed to handle voice not solid tone. This makes the tones not as stable as they are in a analog environment.
Its also worthy of note in the early days Motorola refused to support QC2/P25 but Harris and Tait had support early on fallowed by kenwood shortly there after Motorola adding support to the APX but not at the beginning as I recall.
I talked to some friends involved in the development of this and they all agreed its the "red neck" was of doing it because why not just use UID paging to the base station radio? why would you want to use a standard developed in the 70's to page on a state of the art digital system........ but here we are enough people wanted it so it got added.
Its also worthy of note Harris radios would pass (with the same level of accuracy) tones generated by a Zetron (or other tone generator) over a P25 channel but a Motorola XTL or Spectra had software that would block this, yes I tried it and a Motorola distorts the tones where as the Harris radio passes them just fine (again same limitation for tone separation), I never grasped there logic in this just to do it later on but /\/\ fallows the money.
talviar
Member
Hmmm.... UID paging... aka call alert.... works great... as long as you don't have a lot of radios in the call list....
Advantage of Two Tone Paging/P25 variant= One set of tones takes about 5-6 seconds to blast out. Can trip any amount of radios. Also- tones go out regardless of whether the UID is affiliated or not.
Disadvantage- a lot of people hate the tones coming out on the Dispatch Talkgroup.
Disadvantage of UID paging/Call Alert- If radio is not affiliated- it takes about 2 seconds before going on to the next one. If radio is affiliated, about 3-4 seconds. Fire Department wants 20 portables activated (cause they are using them as pagers as well as radios) Can take a bit for the group to send out.
2nd Disadvantage of Call Alert- Page Stack (at least on the Moto MCC7500) limited to 50 elements. Multi department dispatch may not let all departments be added to the page stack before sending. Requires a little bit of intervention and understanding by dispatcher to know how to send everything out.
Now for more of the real world.... Some of us use automatic paging interfaces between our CAD system and the radio system. -Tyler/NWS Enterprise CAD- MCC7500 Interface as an example. All the paging/call alert entries entered in to the unit tone paging database. When unit is marked as dispatched, sends the page group to the radio system via an associated MCC7500 console. Some of our dispatches have 7 or 8 departments on them with a total of 155 page elements to send. With a max batch of 50 in the queue, 4 queues used by the system to send the batch. Takes approximately 4 minutes to send out and "finish". There are things that can be done to allow tones/base radio UID for siren activation to activate separate from the individual radio call alerts. But that requires more consoles with the interface software loaded on them.
Two Tone may be antiquated and "red neck" but it works and works well and fast. UID Paging/Call alert- works well-- but not the fastest when lots of radios are paged.
It would be great if there was a group ID that could be used to mass call alert multiple radios (similar to the Alpha pagers years ago that had two CAP Codes, one for individual page, and one for group page) But too many think this is archaic and antiquated. Why send a group when an individual UID can be paged?
Several ICORRS Counties are implementing two tone paging on P25- Fayette, Indiana, Cambria are 3 that I am aware of. Washington and Allegheny are looking at this for paging as well.
As always- just my $7.85 (had to add fuel surcharge and import tax to my $.02)-- Your mileage may vary, no warranty expressed or implied, and this is my professional thoughts and not representative of my employer.
The way it was pitched was to just page alert the Stations base radio (thats on all the time) and have that ID in all the pagers and have some type of alert tone go out prior to the announcement for those that where on a radio and not a pager since there radio wouldn't activate but trying to sell that to people who only know QC2........ yea.
Cambria, Butler and Fayette are actively paging on P25 Indiana is set up to do it form what Im told but haven't begun due to them only getting part of the grant they applied for so they are still on pocsag, the tone you hear on EMS is a generic tone.
I personally don't have an issue with QC2/P25 it works and its someting people understand the basics of, but getting it though to people that not as many tone combinations exist and "your tones may not be 1:1 for your analog" based on who singed up to have there digital tones turned on first is like herdign cats, The departments that got in ealry are 1:1.
Il attach the same: this is my own pesonal opion and not reflective of my employer in any way shape or form.
talviar
Member
That works perfect in one case- you are using Unication pagers, --AND-- the pager is in the same RF site footprint (not tower site) that the base station is in. The call alert is not sent out across all sites control channels.
With the P25/QC2 paging, the page/dispatch talkgroup can be set to be a required to carry on certain sites and required to transmit regardless of whether a radio is affiliate or not so the tones and message will go out.
Why isn’t this information in the Wiki for Cambria County? That’s the first place many people look.
Rather simply: We didn't know about the ASR sites at the time....
I just Re-read this part of your reply. There is a county in PA (i thought it was lancaster but looking at it i was mistaken), each department has a page TG (this is a supported paging method by Unicaiton) and in there radios this TG is set as the Announcement group. I dont listen to this system and when I asked how it works with system loading all i was told was "its not that big of a deal" *shrugs*.
If you have 15 talk paths in the system and have a major incident that you need to send 15 departments pluss suport all the other radio trafic its going to go sideways in a hurry. never understood why that was a thing tbh. If P25 handeld patched groups more like tetra it woudnt be that big of a deal.
talviar
Member
15 talkgroups in a Multiselect using an MCC7500 console on a Motorola system uses 1 talkpath. The TG's are essentially merged by the system to be all available on the same talkpath. However, that requires a dispatcher to set up a multiselect with all these departments for a dispatch.
As well as a unique dispatch talkgroup for each department. While that works, I personally would not recommend it.
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