PSR500 on P25 LSM

[MTS2000des]

Anyone else using a PSR500/600 on a P25 LSM (simulcast) system and having any good reliable performance? It absolutely sucks on the city of Atlanta's new P25 800 TRS. I've replaced the stock antenna with an 800MHz duckie but only decode about 60 percent of the calls, and lots of garble, watery audio. It does have the latest firmware (1.7) and works wonderfully on conventional and trunked analog (what little there is left in metro ATL) and fine on the one non-simulcast digitial system (MARTA) but it not much better than the Pro-96 it replaced (it doesn't do that annoying motorboating thank God)

I'm just frustrated, all three major counties in Metro Atlanta are using simulcast Astro 25 800TRS systems, and there doesn't seem to be a scanner that can reliably decode CQPSK/LSM properly. Hey GRE I'd gladly pay for a firmware/DSP refresh that can improve upon this.

[rmiller818]

When I am not at home my Pro-106 works great! Seems I remember getting a pretty good signal from Atlanta inside the perimeter. Outside of that, not much.

[AlabamaRS]

You may want to post your problem in the Georgia forum, May get more help & tips there

[MTS2000des]

the problem isn't specific to just Georgia, it is that the radio apparently cannot properly decode IMBE packets on Astro 25 simulcast trunking systems which use CQPSK LSM versus C4FM for a digital modulator. I was hoping that this issue would be addressed in digital scanners by now. Albeit, the PSR500 is much better than it's predecessor (the Pro-96) but still a miserable scanning experience.

Problem is most of the newer 800 trunking systems being pushed by Motorola are simulcast systems using CQPSK/LSM and thus, scanners do a poor job of decoding audio. It's a shame because the PSR500 is a fine scanner, it sounds great on non-simulcast P25, analog and conventional digital and FM. It was a snap to load up with WIN500 and has great sounding audio. I just wish GRE or someone would build a scanner that can receive CQPSK/LSM properly.

[jehm1212]

I couldn't agree more. My county is in the process of migrating to a brand new P25 simulcast system with LSM. So far, the experience has been nothing short of depressing. If I position the scanner just right, it receives the system reliably. But if I'm on the move, especially in a vehicle, performance is abysmal. It doesn't matter if I use a rubber-duckie or an NMO hole-mounted antenna. Attenuating does nothing.

And my PSR-500 performs so well on every single other system I listen to, analog and digital. It makes me sad more than anything else. The system may as well be fully encrypted based on my monitoring thus far.

I could understand if this was a relatively new issue, or if it was isolated to one or two systems nationwide. But, this is a growing trend among new P25 systems. Every day I see more lamentations over LSM and the ensuing lack of reception. And, it affects both Uniden and GRE. Whoever gets a good fix on the market first will certainly have a leg up.

[blantonl]

LSM issues with the current production models of scanners are due to multipath. Because simulcast sites transmit from multiple locations, the current scanner's timing of recovering the voice packets is problematic. It is no different than being outside a simulcast layer that broadcasts in analog and you get the "choppy" sound from multipath issues.

The ONLY solution at this time is to point a Yagi in the direction of the closest tower or find a null in your current antenna's location that allows favored reception from a local tower.

Unfortunately, when you are mobile the problems are extremely acute. ;( I've experienced this first hand, most notably in the Austin TX area, which runs two LSM layers in the county (Travis County, TX).

Warm regards,

[MTS2000des]

and this means the scanner manufacturers have much to learn about building digital front ends. LSM is fast becoming the system voice of many urban area digital 700/800 systems. The multipath issue was addressed early on and system radios (even low end ones like the XTS1500) can perform flawlessly so it would seem to me that they have much more work to do before their products are ready for prime time.

I guess I have one nice nearly new PSR500 for sale soon being that I cannot use it reliably. It really sucks because I love the radio. Guess it's going back to scanning my local DTRS with an XTS3000 programmed RX only conventional only...brings us back to the "golden age" where scanning was a sport when trunking systems came to public safety in the late 1980's. I can recall wearing out the keypad monitoring the (still in operation 20 years later) Fulton county TRS following calls.

[rmiller818]

I would love if someone would build a pure digital trunking scanner that would perform as well as a subscriber radio. One can dream...

[rmiller818]

Forgot to mention this before, I pretty much leave the attenuator on all the time. I only use the attenuator on the system, not the global attenuator. I forgot, where a bouts do you live?

[MTS2000des]

Smyrna, specifically Kings Springs...about 1.2 miles from the prime site at ET Bryant and about 2.8 miles from Riverwood prime site. Reception on Cobb is horrible as it is on every digital scanner I've tried here. Atlanta's new system is no better. I've given up, have a sale pending on the PSR500 awaiting payment. Meanwhile, I'll go back to listening to the work radio (which sucks because it doesn't have all the TG's I want to listen to and nothing outside of Cobb) or scanning the systems conventionally on my XTS3000. Believe me I miss fewer calls "manually scanning" like we did in the old days on the XTS than came through any digital trunking scanner.

I've said it before, when Uniden, GRE, Icom or whoever builds a scanner that can actually receive LSM, I'd be the first to buy one, regardless of price.

[DaveIN]

Good luck. Even the system users complain about the reception of their "brick" radios.

The best thing you can do is what Lindsay already pointed out, point a beam. Don't expect anything earth shaking for LSM from the scanner manufactures out of the price range of the current digital trunking scanners.

[MTS2000des]

the beam option isn't a reality in my world. and I am one of those users of a simulcast Astro 25 system, though I don't regard my XTS2500 as a "brick", my work radio while not perfect and as clean sounding as our older Smartnet system, doesn't drop out like this. It cannot be that expensive to build the capability in, it's just a matter of market demand. If Motorola can sell basic P25 trunking radios ala XTS1500 that have transmitter sections for $1200 that work find on such networks I don't see why someone cannot build a RECEIVER for half that. I'd pay $1000 for such a scanner if it worked correctly and I know I am not alone.

With simulcast becoming dominant on 800MHz digital systems, they will miss out on alot of sales, especially less tech savvy consumers who aren't going to erect an array of expensive antennas to monitor their local PD/FD systems when they were using a handheld scanner with a rubber duck before. That just isn't practical.

[DaveIN]

There are others that feel as you do, that the $500 range is plenty of money for a digital capable scanner that should work as well as the system radios and it "could" happen, however the reality is that unless the end users in mass come together and say they will not purchase another digital capable scanner until this problem is fixed, then it's just not going to happen in a scanning radio platform. You can go talk to Icom, Yaesu, or some of the higher end "receiver" markets and see there eyes glaze over when you talk to them about trunking features, because they really don't want to be involved with something they sell to their professional market and feel like they gain more from not including trunking in their receivers. The current manufacturers don't have the resources to go out and look at every LSM problem system and adjust the P25 settings to match each setting, and there is obviously no magic bullet to cure the problem, or it would have been done to the best of the radios capability, but then your preaching to the choir.

[wwhitby]

It sounds like GRE needs to come up with a DSP update for LSM systems.....

I agree, it is very frustrating to spend a good chunk of money on a scanner that doesn't work for you. I've been happy with my '500, except for the lousy VHF reception. It gets overwhelmed when you get closer to metro areas, and VHF is still king around here.

Warren

[DaveIN]

What would you suggest for an update Warren? Is there a magic bullet that would solve the multipath issue for all LSM systems? As I recall, GRE did try different things with the PRO-96 firmware to try to adapt to the problem, but were not totally able to cure the problem for multipath and LSM systems were just coming on line. They have improved with the PSR500 with P25 C-QPSK signals, but there just isn't an easy way to solve the multipath problem.
Pro-96 - The RadioReference Wiki

[wwhitby]

Originally Posted by DaveIN

What would you suggest for an update Warren? Is there a magic bullet that would solve the multipath issue for all LSM systems?

I don't know, since I do not live in an area that experiences multipath related LSM systems.

Why do you feel the need to be confrontational? After all, I was making an observation that i'm sure many folks agree with.