Baltimore County P25 and my Pro106 scanner

[ka3jjz]

If you don't have a USB cable between your PC and scanner (and unlike it's GRE cousin, the 106 doesn't come with it), you'll need one. This article gives you the SKU numbers to look for, and installation hints

Connecting scanners via USB - The RadioReference Wiki

Just as a side note - you'd have to do something very similar if you had the 800, so get used to it now....

Mike

[ebxgsxr]

oh ok. i do have the programming cable for the scanner (seller included it with the scanner).

[ebxgsxr]

ok. i have upgraded to the newest version 2.1, signal strength on the display is a full 5 bars, the "T" flashes (correct me if i am wrong indicating that trunking information was received), but i still get choppy, incomplete transmissions.

i'm waiting for the seller to respond back & then i'm going to fail a claim through ebay's buyer protection program. as long as they refund my money, i might try looking for a PSR800.

[ka3jjz]

Since you say you get a full 5 bars on your signal meter, it's very likely you're getting overloaded. In this case, given how poorly a lot of these scanners work with LSM, that might well be causing your distortion issues. You didn't say whether you put your attenuator on - I would start there, and move around the house a bit. I had to turn mine on just to start getting anything, much less the choppy sigs you describe.

There are also specific settings you can change that are mentioned in the programming article of the wiki I gave in an earlier message (you did read it, right? Of course you did...)

Mike

[ebxgsxr]

moving around the house doesn't matter too much. i do have the attenuator on (done through WIN500, right?) and i did read the article & have me settings on stationary instead of roam.

[troymail]

In my testing early on when BCounty came online with the current system, I found spots where I could receive the system without an antenna (Frederick Rd and Rolling Rd -- I believe there is a tower at Rt 40 and Rolling Rd).... but then I could drive down the road (just south of Catonsville HS) and it was a "dead spot" to my scanners.

I'm have both of my 800s parked on the Maryland FiRST system (one on Baltimore site and the other on the Anne Arundel site). Interesting (frustratingly), the Baltimore site comes in fairly consistently and stable with the radio in a certain spot in my house. However, the other radio requires me to move it "slightly" every once in a while to maintain reception (and I'm sitting between two towers which is probably part of the problem). I had to move the AA site radio 3 inches to the left this morning.....

The Baltimore site radio is using a RS 800 Mhz antenna. I believe I'm receiving the tower at Bush St (just off Rt 295 near Russell)

The Anne Arundel site radio is (currently) using a little RS "stubby" antenna (I want the radio to "see" the BWI tower and ignore the Crownsville tower).

I guess what I'm saying it that is may be easier to receive a site/system when you are mostly in range of a single tower/transmitter (outside the intended area). When you are between several towers/transmitters, the scanner tries to receive all of the signals and that's when there are problems.

[k3ygc]

ok let me expand this thread.i have several rs scanners which will not pickup the current digital baltimore county system...what is the best bet for a new scanner...any price info? i prefer a handheld but would like info on base scanners too....thanks mike/k3ygc

[ka3jjz]

There are only 3 that could qualify - the PRO-106, PRO-197 or the PRO-18. I don't think I've seen any reports on the 18 yet, and the other 2 really depend on where you are, and how comfortable you are finageling (yes that's a tech term) with some of the options, as well as the antenna you are using...

However it appears GRE's PSR-800 seems to work well for those that try it - I'd read through this entire thread and form your own opinions...Mike

[kc4jgc]

Wirelessly posted (BlackBerry8320/4.5.0.81 Profile/MIDP-2.0 Configuration/CLDC-1.1 VendorID/100)

Last time I was in the area (Jan 17), I was waiting for a truck to finish a delivery and get out of my way so that I could start mine. As I was waiting, I decided to play with my settings for both BAL city and county systems. I activated the attenuator and deactivated the AGC with some improvement in reception with still some dropouts but not as much as before the changes. I should note I was at BAL Nat'l Pk and Ingleside Rd. After the other driver left and I was able to get into position.for my delivery, I brought my 106 back into the trailer with me. I found that just like Roanoke VA, another city where scannists.were complaining about reception problems due to multicast sites, the problem cleared up the further into the trailer I brought the scanner. I'm not saying that the best way to fix the multipath is to mount scanners inside 53'freight trailers, but I think it does point to a conclusion: the best way to eliminate dropouts due to multipath/ simulcast systems is to attenuate as much as possible! A cheap and dirty method might be placing your scanner in a metal lunchbox. A more practical way would be to obtain an attenuator box placing it in line between the scanner and antenna. I wish I had a box to test this theory out. Any foxhunters around?

[k3ygc]

Originally Posted by ka3jjz

There are only 3 that could qualify - the PRO-106, PRO-197 or the PRO-18. I don't think I've seen any reports on the 18 yet, and the other 2 really depend on where you are, and how comfortable you are finageling (yes that's a tech term) with some of the options, as well as the antenna you are using...

However it appears GRE's PSR-800 seems to work well for those that try it - I'd read through this entire thread and form your own opinions...Mike

ok the 106 is not in stock .and the current RS employees in the area don't have a clue what they do, so i ordered a bcd396xt. hope it does the job./s/ mike

[fourwd1]

I monitor Balt County with a PRO-106 and a PSR-800, both with the latest updates.
The 106 does a much better job on Balt County anywhere along my commute from Social Security to BWI.
The PSR800 which I got to monitor the FIRST system, has not picked up one word from it since I got it.

[BaltimoreScanner]

I just found this thread and have unfortunately tried every suggestion on here. I am ready to just sell my pro-106. I live less than a mile away from precinct 12 and can not receive anything at all yet from my office, in a basement at Hopkins, i can pick it up. I am at my wits end!!!

[dpcain]

At your house, is it a case of good RSSI with really poor decoding, or just no RSSI at all?

[BaltimoreScanner]

Originally Posted by dpcain

At your house, is it a case of good RSSI with really poor decoding, or just no RSSI at all?

No problem with the RSSI it seems to be all a decoding problem from home.

[Bugkiller]

I agree with Baltimore Scanner, I am also feed up with my GRE 500 and would like to sell it. I live in the Woodlawn Md and I can not pick up things on my street. I can pick up the east side of Baltimore Co. but not where I live. If I am on the east side of town I can pick up Woodlawn but not the east side of town. I have tried several different types of antennas, software adjustment, moving around the house, everything. I give up.

[dpcain]

Originally Posted by BaltimoreScanner

No problem with the RSSI it seems to be all a decoding problem from home.

Scuse me if this goes too far into basics, but it's probably better to be over-inclusive than under-.

The most common problem that shows as a terrible CC decode rate with strong RSSI is caused by issues with LSM- Linear Simulcast Modulation, Motorola's P25 Phase I modulation. This uses CQPSK- Compatible Quadrature Phase Shift Keying - to transmit data packets (which include voice on a digital system) at a high rate in wide-area simulcast systems. The chief advantage of this particular modulation is that there is a matching decode setup on the subscriber radio. This software receives data packets that in a wide area simulcast system might be coming from multiple towers at the same time. However, due to distance differences, these identical packets may be received at different times, creating a sort of parallax effect. The subscriber radio's software receives both sets of identical packets, but first aligns them before decoding so that the digital decoding software then receives what appears to be one image without any parallax.

Baltimore County has a massive simulcast system with at least 10 (can't remember if it's more of the total 18) tower sites simulcasting the south site. This means that CQPSK LSM is vital to allow subscriber units to decode the mess of unsynced packets. On the bright side, their thousand-dollar portables have LSM-compatible software inside, so they get great coverage. Some scanners have limited LSM support- for instance, the PSR-800's most recent firmware update added LSM-specific support that was like night and day for me on the other side of the county.

On the downside, however, most digital scanners built in the last few years are designed for C4FM, a slightly older modulation scheme best used in non-simulcast systems. C4FM-designed scanners WILL receive CQPSK, but only if they don't have two strong conflicting signals. In your case, from where you said you are, you are likely getting a mix of the Northpoint, Sparrows Point, Essex, and Allender towers, or any two or three of those. I haven't used a PRO-106, but from what you're saying it's evident that it doesn't have LSM support. In your house, you get that mix and can't decode it, even though your radio shows high RSSI, and at work, you're getting a single tower, maybe Fire HQ in Towson and your radio is coping just fine.

As a solution, I'd suggest a combination of positioning and possibly baffling your antenna to focus on a singe tower site. This may help you, geographically speaking: http://wiki.radioreference.com/image...tCountyP25.jpg

[BaltimoreScanner]

Originally Posted by dpcain

Scuse me if this goes too far into basics, but it's probably better to be over-inclusive than under-.

The most common problem that shows as a terrible CC decode rate with strong RSSI is caused by issues with LSM- Linear Simulcast Modulation, Motorola's P25 Phase I modulation. This uses CQPSK- Compatible Quadrature Phase Shift Keying - to transmit data packets (which include voice on a digital system) at a high rate in wide-area simulcast systems. The chief advantage of this particular modulation is that there is a matching decode setup on the subscriber radio. This software receives data packets that in a wide area simulcast system might be coming from multiple towers at the same time. However, due to distance differences, these identical packets may be received at different times, creating a sort of parallax effect. The subscriber radio's software receives both sets of identical packets, but first aligns them before decoding so that the digital decoding software then receives what appears to be one image without any parallax.

Baltimore County has a massive simulcast system with at least 10 (can't remember if it's more of the total 18) tower sites simulcasting the south site. This means that CQPSK LSM is vital to allow subscriber units to decode the mess of unsynced packets. On the bright side, their thousand-dollar portables have LSM-compatible software inside, so they get great coverage. Some scanners have limited LSM support- for instance, the PSR-800's most recent firmware update added LSM-specific support that was like night and day for me on the other side of the county.

On the downside, however, most digital scanners built in the last few years are designed for C4FM, a slightly older modulation scheme best used in non-simulcast systems. C4FM-designed scanners WILL receive CQPSK, but only if they don't have two strong conflicting signals. In your case, from where you said you are, you are likely getting a mix of the Northpoint, Sparrows Point, Essex, and Allender towers, or any two or three of those. I haven't used a PRO-106, but from what you're saying it's evident that it doesn't have LSM support. In your house, you get that mix and can't decode it, even though your radio shows high RSSI, and at work, you're getting a single tower, maybe Fire HQ in Towson and your radio is coping just fine.

As a solution, I'd suggest a combination of positioning and possibly baffling your antenna to focus on a singe tower site. This may help you, geographically speaking: http://wiki.radioreference.com/image...tCountyP25.jpg

This is great! I will give this a shot! Thanks for all the info and for all your help! I will post with results. i can not thank you enough even if I have no success,

[dcr_inc]

Another added item... Turn the DSP AGC OFF... This helps greatly !!

[dpcain]

Originally Posted by BaltimoreScanner

i can not thank you enough even if I have no success,

Buy me a bagel.

[BaltimoreScanner]

Originally Posted by dpcain

Buy me a bagel.

Sure! LOL