Phase 1 ... Phase 2?

[jacon12]

1- What is the difference between a P25 Phase 1 system and a P25 Phase 2?
2- Will the PSR-800 receive a Phase 1 system ok?
The reason I ask is that I downloaded and installed the latest RR data and installed the Houston County, Ga (Warner Robins, Centerville and Perry) databases, put them in a scan list, made sure it was enabled etc. but I'm not receiving anything. It's scanning but not 'seeing'. I have a Uniden scanner that I have NOT updated with this information and it is still receiving Houston County just fine. I wish I had backed up the info somehow.
Did I go wrong in trusting the RR data base for this county or do I have something set wrong?
Jarrell

 

[marksmith]

The PSR -800 will receive p1 and p2 communication systems with the latest firmware. Can't speak for the specific system you are trying to receive. Is global attenuation turned on. If so turn off. Other than that if you have any scanner receiving the site/system, then the 800 should also.

Mark
536/996P2/HP1e/HP2e/996XT/
396XT/PSR800/PRO668/PRO652

 

[W8RMH]

1 - APCO Project 25 - The RadioReference Wiki

 

[n5ims]

1- What is the difference between a P25 Phase 1 system and a P25 Phase 2?

Phase 1 - P-25 FDMA digital signal. Single voice/data signal per channel.

Phase 2 - P-25 TDMA digital signal. Two voice/data signals per channel. Channel divided into timeslots and each signal on its assigned timeslot.

There are more differences, but this is the most significant one.

2- Will the PSR-800 receive a Phase 1 system ok?

Yes, it will work just fine on a Phase 1 system.

The reason I ask is that I downloaded and installed the latest RR data and installed the Houston County, Ga (Warner Robins, Centerville and Perry) databases, put them in a scan list, made sure it was enabled etc. but I'm not receiving anything. It's scanning but not 'seeing'. I have a Uniden scanner that I have NOT updated with this information and it is still receiving Houston County just fine. I wish I had backed up the info somehow.
Did I go wrong in trusting the RR data base for this county or do I have something set wrong?
Jarrell

You did fine, but there may be issues if you have strong signals from more than one tower site since it's a simulcast system. A simulcast system transmits the exact same signals on multiple towers to help low power handheld radio coverage on the system. It also causes havoc on scanners (regardless of brand or quality) if they get signals from multiple towers. These signals will mix together and cause distortion and make it seam like you have too little signal strength, when in reality you have too much signal - yes, that's actually a real problem.

The fix is to reduce your signal strength (using the scanner's attenuator if available), a directional antenna, or something else to have your scanner only pick up signals from a single tower. When mobile, I often am able to improve reception by holding my antenna so my hand helps to block some of the signal from reaching the scanner.

This article from the RR Wiki may help you understand what's going on. Simulcast digital distortion - The RadioReference Wiki

 

[JD21960]

Phase 1 Phase 2

I agree with the others. HERE in the state of ILL-annoyed, we have a Starcom21 phase 1 and phase 2 mix. I get it perfectly even with simulcast in Phase 1 with my old Pro96. But Pro96 can't get TDMA, Phase 2 which I need now as a lot of the talk-groups are phase 2 TDMA. My new Whistler WS1080 had the same problems mentioned. Couldn't' get it at home unless I attenuated the SITE itself. I'm NOT talking about Global Attn button on the front of the scanner (PSR-800) that just deadens ALL channels which we don't want. Attenuating the SITE nearest to you on the SYSTEM in EZScan might help. *SEE link photo of my post in that thread* It's fixed my Simulcast problem with the Cook Co SITE. Also got a 700/800 mhz Yagi that totally locked everything in and TDMA talk-groups are perfect now. Haven't had nearly any problems while mobile with RShack 800mhz or the Scanner Master 800mhz duckies.
**link for photo of EZScan example on other thread
http://forums.radioreference.com/ar...um/310066-pro-668-not-receiving-rwc-much.html

 

[jacon12]

Hmmm.... well, thank you all for the information. I better understand the problem now with simulcast. Sitting here watching the psr 800 I see it scanning and now and then it will stop on"Houston County Sheriff's office 36 Lo", but there is no audio. If I turn the squelch to 0 I get static and it will go away turning the squelch back up to about 3 or 4 or so.
Jarrell