GRE PSR-500 in NH Yet?
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drumbumer
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I don't have one but am considering buying one. I have also heard about some of the issues. I read that the PSR-500 does not pick up FM traffic. Does that mean that it will not pick up channels such as LP North/ South and Lakes Region Fire?
The P25 problems are trunking. I am receiving P25 conventional here on Cape Cod just fine. It won't be an issue for you if you're listening to any of the VHF-HI public safety P25 up there. Audio quality is superb.
n1das
Member
I'm interested in a PSR-500 but I'm going to wait until after few firmware updates happen to get all the bugs out before I grab one.
GRE-500 options
The most obvious and important option that the GRE-500 has that the current Radio Shack & Uniden scanners lack (96 series and 795/796 series respectively) is the ability to program in or decode a P25 system's Network Access Code (NAC). The ability to employ the NAC will allow users the ability to eliminate co-channel interference from distant users operating in analog mode or using another P25 system wiith a different NAC.
For those of you that may not have a P25 scanner yet, in order to receive a conventional P25 signal using either a current Radio Shack or Uniden scanner you must leave that channel in open squelch mode, subkecting the user to potentially all kinds of co-channel interference.
What will be interesting to see is if the GRE-500 can help eliminate the confusion some listeners have about receiving encrypted P25 signals within the New Hampshire LAWNET conventional system. Currently the limited vocoder circuits in both the Radio Shack and Uniden scanners cannot differentiate voice from embedded laptop digital transmissions (State Police units using CAR 54 laptop technology on Troop channels, especially Troops A & E). Also, if there is a significant difference in audio levels amongst two units communicating together....say a mobile with very hot audio versus a troop station with a normal level, the vocoders in both previously mentioned brands cannot adjust quickly enough and will decode one voice path correctly (usually the base) but pass the other unit's audio (usually a mobile or portable) as digital hash. This is very noticable in repeter based operations, such as the State Police Troops already mentioned. These two issues account for the majority of false reports of encryted transmissions.
Hopefully the GRE-500 vocoder has enough improvement (as claimed by GRE) to overcome these limitations and provide much better P25 recovered audio.
Those differences alone, if the GRE does indeed perform as advertised, make the upgrade to the GRE worth the price to a serious listener.
LPD7 said:
The most obvious and important option that the GRE-500 has that the current Radio Shack & Uniden scanners lack (96 series and 795/796 series respectively) is the ability to program in or decode a P25 system's Network Access Code (NAC). The ability to employ the NAC will allow users the ability to eliminate co-channel interference from distant users operating in analog mode or using another P25 system wiith a different NAC.
For those of you that may not have a P25 scanner yet, in order to receive a conventional P25 signal using either a current Radio Shack or Uniden scanner you must leave that channel in open squelch mode, subkecting the user to potentially all kinds of co-channel interference.
What will be interesting to see is if the GRE-500 can help eliminate the confusion some listeners have about receiving encrypted P25 signals within the New Hampshire LAWNET conventional system. Currently the limited vocoder circuits in both the Radio Shack and Uniden scanners cannot differentiate voice from embedded laptop digital transmissions (State Police units using CAR 54 laptop technology on Troop channels, especially Troops A & E). Also, if there is a significant difference in audio levels amongst two units communicating together....say a mobile with very hot audio versus a troop station with a normal level, the vocoders in both previously mentioned brands cannot adjust quickly enough and will decode one voice path correctly (usually the base) but pass the other unit's audio (usually a mobile or portable) as digital hash. This is very noticable in repeter based operations, such as the State Police Troops already mentioned. These two issues account for the majority of false reports of encryted transmissions.
Hopefully the GRE-500 vocoder has enough improvement (as claimed by GRE) to overcome these limitations and provide much better P25 recovered audio.
Those differences alone, if the GRE does indeed perform as advertised, make the upgrade to the GRE worth the price to a serious listener.
LPD7
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About NHSP and Encryption, i went to Boston the other day and listened to the Federal PRotective Service (417.2000 P25) and herd their Encryption, and after that i herd what i thought was Encryption on A-Troop and the FPS ENC sounded like a Humming sound in the Bottom, and very choppy, nothing like NHSP. the NHSP problem might be from me not getting the Repeated Traffic from the Mobile unit. Can they Transmit info via the Laptop, and at the Same time make a transmission in P25 Digital mode?
Prioritization of voice over data
Actually, when programming the unit you have the ability to program voice as priority over data...that's how this system is set up. In the NHSP systems voice takes priority over data, both cannot co-exist at the same time.
From my observations though, the majority of the time my PRO-2096 is falsely indicating ENC, it is because the audio level of the transmitting field unit is substantially different then that of the base. One of the critical components of setting up a properly operating P25 system is matching audio levels...and without mentioning any names some agencies are not all that good at it. The other issue is that these conventional repeater systems utilize remote recieive voting systems. You are supposed to use digitally conditioned phone circuits to route remote received audio back to the system comparator and eventually the repeater for rebroadcast. Some agencies, in order to save money, use regular POTS lines, which induce widely variable audio levels that can confuse a listener's vocoder.
I would bet that in most occasions it is distorted audio coming in to the repeater via a remote receive site that causes our present scanners to lose sync and reproduce digital hash.
LPD7 said:
Actually, when programming the unit you have the ability to program voice as priority over data...that's how this system is set up. In the NHSP systems voice takes priority over data, both cannot co-exist at the same time.
From my observations though, the majority of the time my PRO-2096 is falsely indicating ENC, it is because the audio level of the transmitting field unit is substantially different then that of the base. One of the critical components of setting up a properly operating P25 system is matching audio levels...and without mentioning any names some agencies are not all that good at it. The other issue is that these conventional repeater systems utilize remote recieive voting systems. You are supposed to use digitally conditioned phone circuits to route remote received audio back to the system comparator and eventually the repeater for rebroadcast. Some agencies, in order to save money, use regular POTS lines, which induce widely variable audio levels that can confuse a listener's vocoder.
I would bet that in most occasions it is distorted audio coming in to the repeater via a remote receive site that causes our present scanners to lose sync and reproduce digital hash.
n1das
Member
plxnbury said:
A P25 scanner with NAC decode capability is THE REASON why I'm considering a GRE PSR-500 in the future. The lack of any NAC decode capability in my current P25 scanners has always been my number one pet peeve about them. It makes it harder to monitor P25-only or mixed P25/analog mode channels when there's some local interference or distant co-channel users which hold the squelch open. The scanner manufacturers kept striking out in this area...until recently with the debut of the PSR-500.
Since I've already got 3 P25 scanners plus a pair of ICOM IC-F70DT P25 handhelds, my need for a PSR-500 is rather weak right now. I plan to wait until after GRE comes out with a firmware upgrade to address the P25 issues on trunked systems since I listen to Nashua's TRS.
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fosters
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- Nov 11, 2004
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Well, I broke down and bought one. I couldn't wait, I guess I needed a new toy to play with over the holidays.
I've only had a chance to play with it a couple hours last night. At first I wasn't very impressed with it. The housing seems pretty cheap and flimsy and I had the floppy antennae that some people have had problems with, so needless to say I was alittle dismayed.
Having said that, than I just dumped a bunch of freq. into the thing and hooked it up to my outside ant. and the thing chirped up a storm! It is very sensitive to say the least. It seems to actually bring in weak signals quite better than my 796. I only had a couple hours to play with it so really haven't had a chance to give it a complete shakedown. I do have the next couple days off so I will give it a going over and let you all know. Unfortunately I'm not close enough to any Trunked Systems to see how it works on those.
Oh, by the way I haven't done any of the upgrades yet, figured I would let it fly til I discovered a problem or GRE gets a comprehensive one available. Also if continues to preform, I may have to find a new home for the 796 and get a 600.
Fosters
I've only had a chance to play with it a couple hours last night. At first I wasn't very impressed with it. The housing seems pretty cheap and flimsy and I had the floppy antennae that some people have had problems with, so needless to say I was alittle dismayed.
Having said that, than I just dumped a bunch of freq. into the thing and hooked it up to my outside ant. and the thing chirped up a storm! It is very sensitive to say the least. It seems to actually bring in weak signals quite better than my 796. I only had a couple hours to play with it so really haven't had a chance to give it a complete shakedown. I do have the next couple days off so I will give it a going over and let you all know. Unfortunately I'm not close enough to any Trunked Systems to see how it works on those.
Oh, by the way I haven't done any of the upgrades yet, figured I would let it fly til I discovered a problem or GRE gets a comprehensive one available. Also if continues to preform, I may have to find a new home for the 796 and get a 600.
Fosters
fosters
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Well, had a little while to play with the new toy over the holiday, not as much as I would like. I'm getting to like it more and more. I punched in 100+ freqs by hand, which I know isn't the easiest way to do it, but it was actually pretty fast. Once you get the hang of it it is no worse than any other radio I own. It is more sensitive than my 796 for sure. Being so it does hang up on a freq every once in a while which is annoying, but I just set the squelch alittle tighter and it is fine. The flashing lights and the alarms are fun to mess around with, though my wife might beg to differ on that. I don't believe it is as fast picking up the conversations as the old one, seems like I miss sometimes the 1st second or two on the call, but it is kinda hard to tell and that will probably just take messing around with the delay and the other "expert" settings alittle.
Over all the only disappointments I have with the radio is it's cheap feel, the way it chews through batteries, and most importantly, the wobbling ant. That is really annoying, so does anyone have a good suggestion for a replacement???? I'm not close enough for 800mhz or trunked stuff, so one that would be good for 150-say 500??
I have tomorrow off as well with no commitments as far as I know so I will keep playing with it and let you all know if something strange comes up, but for right now it's a pretty decent radio.
Fosters
Over all the only disappointments I have with the radio is it's cheap feel, the way it chews through batteries, and most importantly, the wobbling ant. That is really annoying, so does anyone have a good suggestion for a replacement???? I'm not close enough for 800mhz or trunked stuff, so one that would be good for 150-say 500??
I have tomorrow off as well with no commitments as far as I know so I will keep playing with it and let you all know if something strange comes up, but for right now it's a pretty decent radio.
Fosters
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