SRRCS P25 vs SRRCS Moto SmartNet II - Uniden 536 not getting P25 Sac

[brumey]

Hello:
I have the Uniden 536 and SDS-100. Using the same two favorite lists, SRRCS and SRRCS P25, same antenna, same location, I can only receive the P25 on my SDS-100. I think I have checked all the obvious (Attenuation, Services, Range, etc). I am using the same lists and profile for both radios.

When I put both in Analyze, the SDS-100 shows a healthy S, Q and A. The 536 has a little signal but no Q or A. I am 45 miles from downtown Sac but on a hill with clear views into the valley. I have an HP1 scanner which exibits the same issue, receiving on the SRRCS but not the SRRCS P25. The 546 does not show system ID's in analyze mode. The SDS-100, even with rubber duch shows ID's. Its driving me nuts.

Is the SDS-100 that much better for P25? I know I can put the rubber duck antenna on it and leave the discone on the 536 and HP1 and still get SRRCS P25 on the SDS-100.

Any advice welcome before I have to sell my 536 and HP1 to get a SDS-200!!!

Thanks...

 

[SteveSimpkin]

Hello:
I have the Uniden 536 and SDS-100. Using the same two favorite lists, SRRCS and SRRCS P25, same antenna, same location, I can only receive the P25 on my SDS-100. I think I have checked all the obvious (Attenuation, Services, Range, etc). I am using the same lists and profile for both radios.

When I put both in Analyze, the SDS-100 shows a healthy S, Q and A. The 536 has a little signal but no Q or A. I am 45 miles from downtown Sac but on a hill with clear views into the valley. I have an HP1 scanner which exibits the same issue, receiving on the SRRCS but not the SRRCS P25. The 546 does not show system ID's in analyze mode. The SDS-100, even with rubber duch shows ID's. Its driving me nuts.

Is the SDS-100 that much better for P25? I know I can put the rubber duck antenna on it and leave the discone on the 536 and HP1 and still get SRRCS P25 on the SDS-100.

Any advice welcome before I have to sell my 536 and HP1 to get a SDS-200!!!

Thanks...

536 and HP1 not receiving local P25 system

Hello: I have the same post in the local area forum but I thought I'd expand to the Uniden experts in the hope of a solution. Hello: I have the Uniden 536, HP1 and SDS-100. Using the same favorite lists, SRRCS and SRRCS P25 (Sacramento, CA), same antenna, same location, I can only receive the...

forums.radioreference.com

 

[MisterLongwire]

Please keep in one or the other.

 

[jonwienke]

If you're using the same antenna and programming for the 536 and the SDS100, then you should expect a SDS200 to perform like the SDS100. The SDS models do much better receiving simulcast, and also multipath signals where you have multiple reflections of the same signal arriving at different times (the cause of "ghosting" in analog TV). The i/q receivers in the SDS models can handle that, conventional receivers can't.

 

[scannerboy02]

You are likely suffering from Linear Simulcast Modulation (LSM) issues. In these situations MORE signal is BAD. Try reducing the amount of signal going into the 536 and/or HP-1. Try using the stock antenna or some other antenna inside your home. Directional antennas pointed at a single tower site also works well. I have found that moving the scanner/antenna a few feet in one direction or the other also makes a big difference.

I have a feeling a lot of people in the Sacramento area are going to get a big surprise on how difficult the new P25 system is going to be on older scanners.

 

[brumey]

Thanks for the suggestion. I will try an internal antenna on the 536 and HP1 tonight to see if that helps. I know the sds-100 works on sacs P25 system with any antenna, outside discone or inside rubber duck.

I assume Sac is moving everything over to P25 off Smartnet II. So, if this is true, maybe I am better getting the SDS-200.

would the LSM issues cause No Receive? The The SQA on the analyzer shows very low signal, no system ID’s no Q or A.

I appreciate all the help

 

[gmclam]

I have several scanners monitoring the Sacramento systems from the same antenna. Both the Sacramento P25 & Roseville P25 systems have great signal strength, but have lousy "reception" on older scanners (PSR-500/PSR-600). I don't have issues with Placer P25 or East Bay, but their signals are weaker (and I'm likely only receiving signals from a single tower each). It's crazy that there is really only one hand-held and one desktop model out there suited to resolve this.

 

[jonwienke]

You are likely suffering from Linear Simulcast Modulation (LSM) issues. In these situations MORE signal is BAD.

Only in a very narrow set of circumstances. All of the following have to be true:

1. The signals from two towers have to be close enough in strength to cause interference.
2. They also have to be significantly different in strength.
3. You have to be able to attenuate the signal enough to push all but the strongest signal below the noise floor of the receiver, but still
4. Not attenuate the strongest signal so much the radio can't hear it any more.

Unless all 4 of those conditions are true, attenuating the signal will not improve simulcast reception. But it is guaranteed to degrade reception for everything else you want to monitor.

 

[brumey]

Thanks for the comments. I did a little more testing tonight, both the HP1 and the SDS-100, stock antenna's, went outside, looking into the Sacramento vallet from 2000' elevation. SDS-100, receiving everything on Sac P25. HP1, deaf. Checked the signal from the analyze function on both radio's and the SDS-100 shows S/Q/A. HP1 nothing. I tried attenuate and again, nothing.

Looks like I'll order a SDS-200 tomorrow.

 

[ScanningHertz]

Looks like I'll order a SDS-200 tomorrow.

Get your SDS200? Results?

 

[brumey]

Successful. SDS-200 (and SDS-100) receive perfectly. 536 just did not received Sac P25.