Static on NHSP freq.?

[tbone9597]

Just a question here about the NHSP using Apco-25. Once in a while I hear static on my Pro-96 like the scanner is not decoding the signal. But this only happens on NH state Police freq. and only certain troopers (Troop D). Does anyone know if certain troopers are using encrytions? Or is this a minor flaw with the Pro-96. I already updated the software off RS website.

Thank you and sorry for the any misspellings.

 

[bezking]

If it's APCO and you are hearing what sounds like 'static', it could be encryption. If it is trunking, it is probably Motorola Securenet, which is encryption.

 

[tbone9597]

It's not trunking because each troop uses one freq. the sound is like an alien talking.

 

[LPD7]

Troops A and D both use some Encryption. Some Troopers use it, not yet herd it on base transmissions. NOT full time.....yet

 

[jimlawrence]

On my Pro-96, P-25 encryption sounds like R2D2. Beeps and boops. It doesn't sound like static or open squelch.

Sometimes a weak P-25 signal won't initialize right and then I'll get that static sound.

 

[tbone9597]

okay i get it but are you saying they are going to be using it full time at some point? I heard it the other night Trooper 421 was using the encrytion. Is the Pro-96 able to listen to the encrytion?

 

[SCPD]

Data terminal not encryption....

This issue about static & the ENC indication pop up here time to time, and most assume that it is because several troops are using encryption.

Actually it is laptop data transmissions you are hearing, not encryption. Several troops (including Troop-A) have units with laptop capability that are interfaced back to the troop. The curent Motorola ASTRO Spectras, and now XTL-5000s come with embeded modems. The State Police have been using a number of CAR-54 setups from the University of New Hampshire that link the laptops back to the troop base station then on to Concord via microwave by transmitting the laptop's data stream over the same voice channels used for tactical communication.

Unfortunately all of today's off the shelf scanners cannot differentiate between the data & voice, so they blurt out the data when its transmitted.

The Motorola system only allows data between voice transmissions, with voice having priority. That is why some folks confuse data with encryption. Thry here a voiced transmission, followed immediately by a waiting data transmission and then assume one side of the conversation is encoded.

Also, the Uniden scanners previously mentioned will display ENC when receiving a data transmission.

If you own a APCO capable mobile or portable radio the unit's software prevents data from being heard.

Finally, in order to be to transmit or receive encrypted P25 signals within the NH system each Troop or PD would need to have encryption boards installed in what is known as the DIU at the local level. This is currently not the case in NH.

Hope this helps explain some of the confusion on this subject.

Unfortunately until manufacturers of scanners give you an option of excluding or filtering digital laptop transmissions while monitoring non-trunked P25 systems you will have to live with this annoyance!

 

[tbone9597]

A friend of mine works for Northfield PD and they are getting the Car-54 setups. Just asking about the State Police because I do not hear the noise all of the time on my Pro-96 on the state police channel. The state police is the only channel that I hear the noise on. As you stated the software on an APCO capable radio prevents the transmission then how can I hear the noise?

Another question for you plxnbury is are the new digital portables that almost all of the state is using now are they linked to these laptop and then on the the dispatch or troop centers?

Thank you for all of your help in this matter, it is just a little confusing this digital mess!

 

[SCPD]

Data transmissions

The NHSP are the only agency actually co-transmitting data alongside voice and only a few troops are set up to do this. These data transmissions are very sporadic but will increase as more SP and MV units activate data terminals in their respective units.

The software on a P25 commercial radio blocks a commercial two-way user from having to listen to data transmissions. That software is not yet currently available for any P25 scanner radio.

Also a digital scanner picks up any and all P25 transmissions on a particular channel. However, a commercial two-way unit is allowed to program unique network IDs that act as a digital version of DCS or PL. Again, no currently available consumer scanner radio can offer this feature.

As for the portable radios being issued, they do have the capability of being linked to a laptop with the appropriate cable, but the portable radio in question must have the appropriate modem with its attendant software installed as an option. This is currently not the case with most of the portable radios being issued statewide.

 

[LPD7]

Northfield Police may be operating in P25 (Simplex) Mode on the Belknap County Freq 154.8600/136.5

 

[SCPD]

clarification on PL or DCS

Northfield Police may be operating in P25 (Simplex) Mode on the Belknap County Freq 154.8600/136.5

Just a quick note, when operating in P25 mode PL (or DCS) is not used. The PL of 136.5 would only be used if the units were transmitting analog.

If you program your scanner in PL mode you will not receive P25 transmissions. Since the P25 transmission does not include the analog PL of 136.5 your scanner will ignore the P25 signal.

 

[zerg901]

I suspect that the data signals will interfere with the voice messages. I think that Baltimore MD FD, Montgomery County MD FD, and Houston TX FD had problems with this for years on end with their MODAT systems. Braintree MA FD also.

Let me explain my point of view.

Trooper 666 says : "Troop F, 666, emergency"

Troop F says : "666 go ahead with your emergency traffic"

Data Modem 999 says - ok the channel is clear - lets send the data - sqwaaaaak (a data modem is not quite as smart as a human - it doesnt know enuff to shut up at this point)

Oooops - Trooper 666 is not happy as his message gets blown away or he gets a bonk, as he tries to transmit.

Perhaps this scenario has been somewhat mitigated with shorter data messages and / or not allowing a data message within 5 seconds of a voice message. Or maybe data users will be advised to not push any buttons when they hear someone sending a voice message - or about to send a voice message. Maybe data users will neeed a little ESP. (What happens if a data modem is programmed to automatically resend lost data?)

Peter S

 

[tbone9597]

A question about PL codes?

you mentioned that if you program your scanner with a PL code you will not hear P25 transmissions. I believe this to be incorrect unless you are talking only about 136.5 codes. I listen to Franklin PD on 154.7850 with a CT code of 254.1. I know I am recieving digital because on the Pro-96 the FM changes to DG. I listen to Belknap county on 154.83 with a PL code of 136.5 and right now they are analog because they had a problem with their equipment when they tried to go digital about a month ago. Just a question about the PL codes and or CT/DC?

 

[SCPD]

Incorrect programming

you mentioned that if you program your scanner with a PL code you will not hear P25 transmissions. I believe this to be incorrect unless you are talking only about 136.5 codes. I listen to Franklin PD on 154.7850 with a CT code of 254.1. I know I am recieving digital because on the Pro-96 the FM changes to DG. I listen to Belknap county on 154.83 with a PL code of 136.5 and right now they are analog because they had a problem with their equipment when they tried to go digital about a month ago. Just a question about the PL codes and or CT/DC?

You have your scanner programmed incorrectly.

You have the proper frequency (154.785) and the proper PL for analog monitoring (136.5) however you have that channel set in the FM mode which means it is ignoring the PL you have set. If you had the frequency set correctly for a PL monitor of 136.5 then the channel would indicate CT (continuous tone) not FM. Likewise if you were monitoring for DCS it would dispaly DT for that channel, not FM.

In the FM mode, which you have set for that channel, allows any and all FM analog transmissions to occur regardless of your PL setting, and also decodes any P25 transmissions while displaying a DG tag.

Hope this helps explain it a little better...

 

[LPD7]

Just a quick note, when operating in P25 mode PL (or DCS) is not used. The PL of 136.5 would only be used if the units were transmitting analog.

If you program your scanner in PL mode you will not receive P25 transmissions. Since the P25 transmission does not include the analog PL of 136.5 your scanner will ignore the P25 signal.

I know that, but Dispatch is still Analog, thats why i listed it that way, P25 Traffic uses a NAC code. I own a Pro-96, and and several Departments are in Mixed Mode

 

[SCPD]

Mixed mode operation

I know that, but Dispatch is still Analog, thats why i listed it that way, P25 Traffic uses a NAC code. I own a Pro-96, and and several Departments are in Mixed Mode

Actually all ten county dispatch centers in the State have mixed mode capilitiy, along with a number of stand alone 24/7 dispatch centers.

Originally a number of law enforcement agencies did not have full compliments of P25 radios, but that problem has now been mostly resolverd.

However, some dispatch centers, like Strafford County Dispatch on 154.725, dispatch a mix of Police, EMS & Fire on the primary law enforcement channel. In Strafford's case it primarily dispatches in digital, but will change over to analog to dispatch several EMS & Fire agencies still on the law enforcement channel.

I realize you understand this but there are a few folks here that I was reminding that if you program a channel with PL or DCS it will not allow P25 transmissions to be received.

 

[tbone9597]

As I mentioned earlier I listen to Franklin PD on 154.7850 with a CT code of 254.1. How is my scanner programmed incorrectly? On my scanner there is no FM and it does not change to DG, it shows CT on this channel. I think I wrote it wrong for the Franklin PD channel. Almost all of the other channels that use digital it switches to DG. If not digital it stays FM.

Is the PL code of 136.5 almost always used for analog channels?

A follow up on my original question that started this thread. The other night I heard the dispatch for Troop D talking to a trooper, and the trooper was talking and the noise that I hate was going on and then the dispatcher said "10-5". So I have to think the trooper was talking using the encrytion equipment that someone stated earlier. I don't think it was the data terminal.

If it is encrytion does anyone know if there are any plans for RS or Uniden to release a software update or plan on selling a digital scanner that will decode or block this noise?

 

[SCPD]

Pl 136.5

As I mentioned earlier I listen to Franklin PD on 154.7850 with a CT code of 254.1. How is my scanner programmed incorrectly? On my scanner there is no FM and it does not change to DG, it shows CT on this channel. I think I wrote it wrong for the Franklin PD channel. Almost all of the other channels that use digital it switches to DG. If not digital it stays FM.

Is the PL code of 136.5 almost always used for analog channels?

A follow up on my original question that started this thread. The other night I heard the dispatch for Troop D talking to a trooper, and the trooper was talking and the noise that I hate was going on and then the dispatcher said "10-5". So I have to think the trooper was talking using the encrytion equipment that someone stated earlier. I don't think it was the data terminal.

If it is encrytion does anyone know if there are any plans for RS or Uniden to release a software update or plan on selling a digital scanner that will decode or block this noise?

The PL of 136.5 is the commom PL used in NH for law enforcement and some fire/ems agencies.

The Troop Stations nor the County dispatch Centers have encryption capabilities. There are a handful of mobile & portable units for special ops in the State that have the encrypted option, but they are few and far between. Virtually all special ops are conducted wither P25 or analog, usually narrowband (12.5 khz spacing).

The consumer grade scanners are great, but still no comparison to a commercial grade two way transceiver. The scanners can easily lose track of the digital signal and cause the recieved signal to go "digital". It is a symptom very prevalent when listening to NHSP sites. For a variety of technical reasons there is a great variance in audio levels within the troop sites. While these audio level differences between the base and mobile units are an annoyance when monitoring with another commercial transceiver radio, these differences do raise havoc with reproduced audio on a consumer grade scanner.

I have listened to my pro-2096 as the received P25 signal "goes digital" while having my XTS-2500 sitting right beside the scanner reproducing perfect audio.

Its just something we'll all have to live with while scanner manufacturers continue to perfect their vocoder circuitry and offer new & upgraded features.

By the way, do not expect widespread encryption anytime soon. The cost to retrofit each dispatch center along with the cost to upgrade current field radios is astonomical! The State still has not completely outfitted police/fire/ems with enough P25 radios to complete a full analog to digital conversion due to lack of funding.

Finally, ICOM is offering a series of mobile & portable radios that are P25 capable and being offered in the $800 range if you trade in any two way radio towards the purchase. If you strictly monitor VHF decent two way commercial equipment is quickly becoming affordable to the volunteer, part-timer or die hard monitor fanatic!

 

[tbone9597]

Thanks for the info and maybe you can give me some more info. I am very interested in your XTS 2500 and info on the ICOM radios. I did some research for the XTS 2500 but a little expensive. Does the XTS 1500 recieve Digital signals? If you can give me info on a really cheap VHF digital radio I would apprecitate it. And where maybe I could buy one cheap.

Another question this one is about HAM radio, how do you go about getting in to it. And what equipment would I need?

Thanks for all of your help.

 

[SCPD]

Radios

Thanks for the info and maybe you can give me some more info. I am very interested in your XTS 2500 and info on the ICOM radios. I did some research for the XTS 2500 but a little expensive. Does the XTS 1500 recieve Digital signals? If you can give me info on a really cheap VHF digital radio I would apprecitate it. And where maybe I could buy one cheap.

Another question this one is about HAM radio, how do you go about getting in to it. And what equipment would I need?

Thanks for all of your help.

Just heading out the door to camp, but yes...you can buy the 1500 with the P25 option.

Cheapest is the offer from ICOM, trade in ANY two way radio and get a 40 watt mobile or 5 watt portable for about $800.....P25 included.

Am also a HAM....will slide you some more info, or I am sure others will jump in with some excellent advice for that worthwhile hobby!