SDPD trunking reception issues

[Defiant]

Is anyone else having issues receiving SDPD dispatch 'channels'? I have used 3 different Uniden trunking scanners and I've noticed a severe degradation when trying to receive various SDPD dispatch channels. It doesn't matter where I'm located, almost all of the SDPD primary dispatch channels sound as if the control channel audio is interfering with the actual voice communications.

 

[nick0909]

What Uniden scanners do you have? Unless they are the SDS100 or 200, they don't fully support the Simulcast system that SD City and County have running now. They kinda work, but depending on how your reception is, they kinda won't, which sounds like what you are experiencing. There are similar posts on this forum with more details if you want to look around, but that is the quick answer.

 

[slapstix]

I’m only getting Southern Division and Central and SDFD just purchased a new chip I thought was the problem on my SDS100. Anyone have any ideas what the problem could be.

 

[tvengr]

ATTN: Database Admin:
On the San Diego City 700 MHz system, the Point Loma and San Pasqual Valley sites both show the same control channel frequencies:

1 (1)	004 (4)	Point Loma Wastewater Treatment Plant	769.51875	769.76875	770.06875	770.50625	770.81875c	771.25625c
1 (1)	005 (5)	San Pasqual Valley	769.51875	770.81875c	771.25625c

 

[Whiskey3JMC]

ATTN: Database Admin:
On the San Diego City 700 MHz system, the Point Loma and San Pasqual Valley sites both show the same control channel frequencies:

Usually it's best to tag the db admin to get their attention on a thread, you can find the admin who made the update in the system's change history page. @inigo88

 

[MtnBiker2005]

What’s the problem?
Site 1-4 and 1-5 they both use the same frequency for the main primary control channel. It’s all fine, no problem found. They are in two different areas.

 

[celbaseman]

I have been seeing some issues with 700 system where they have been changing the control channel off of the primary channel quite a bit. Also, unless you are up near San Pasquel or near the Point loma treatment plant, lock out looking in those control channels, just going to slow down your scanner. Right now, the control channel is 770.30625.

 

[slapstix]

Looking for help here in San Diego with my SDS100. I am not getting any police dispatch on 800mhz only fire dispatch.

 

[celbaseman]

SDPD has moved to the San Diego 700 MHz system. You will need to use that system.

 

[slapstix]

so no longer on 800mhz?

 

[slapstix]

SDPD has moved to the San Diego 700 MHz system. You will need to use that system.

Still not working on 700mhz

 

[Peter_SD911]

so no longer on 800mhz?

The legacy 800mhz SDPD is still working fine .
Hearing it in coastal Carlsbad like usual.

Happy Easter!

 

[Elpablo]

I’m only getting Southern Division and Central and SDFD just purchased a new chip I thought was the problem on my SDS100. Anyone have any ideas what the problem could be.

I too am experiencing what Slapstix mentions. I am running one scanner on the 800 and another on the 700. For the 800 system, I am only getting the talkgroups you describe above (Western, Northern, Mid-City or Eastern are not coming up as they do on the 700 system). Maybe they are starting to shutdown patrol talk-groups on the 800 system.

 

[inigo88]

Usually it's best to tag the db admin to get their attention on a thread, you can find the admin who made the update in the system's change history page. @inigo88

@tvengr and @Whiskey3JMC ,

Both the Point Loma and San Pasqual sites are very geographically isolated. As such it looks like the city has chosen to reuse the control channel frequencies on both sites. This is not an error in the database.

 

[Defiant]

What Uniden scanners do you have? Unless they are the SDS100 or 200, they don't fully support the Simulcast system that SD City and County have running now. They kinda work, but depending on how your reception is, they kinda won't, which sounds like what you are experiencing. There are similar posts on this forum with more details if you want to look around, but that is the quick answer.

I'm using the following handheld and mobile scanners: BCD396XT, BCD325P2, BCD996XT, BCD996P2.
For the longest time, ALL of these scanners worked fine (except for the RCS conversion to Phase 2) and they ALL work just fine for the US Mil trunked system, SD City 700 trunk system and except for the P25 Phase 2 systems that the older scanners can't decode, even the other trunked systems such as SDGE (most of the time with prevailing winds and being pushed).

 

[JoeyC]

I too am experiencing what Slapstix mentions. I am running one scanner on the 800 and another on the 700. For the 800 system, I am only getting the talkgroups you describe above (Western, Northern, Mid-City or Eastern are not coming up as they do on the 700 system). Maybe they are starting to shutdown patrol talk-groups on the 800 system.

If there is no subscriber radio tuned to the talkgroup ON THE 800 system, you will not hear anything on its talkgroup. This has been the case for a while now as almost all radios are on the 700 mHz system.

 

[inigo88]

If there is no subscriber radio tuned to the talkgroup ON THE 800 system, you will not hear anything on its talkgroup. This has been the case for a while now as almost all radios are on the 700 mHz system.

This is exactly right. The 800 MHz and 700 MHz systems share a common zone controller (basically the central computer running the system). The zone controller keeps track of which radio IDs are logged on (affiliated) to each site, and will only carry traffic on that site for talkgroups with currently affiliated radios. As a user drives out of range, the radio will roam to a new site with the strongest signal just like your cell phone, and if that was the only affiliated user on that talkgroup then the original site will cease repeating that talkgroup.

Eventually SDPD will fully upgrade to 700 MHz radios and all the 800 MHz sites will stop carrying any SDPD talkgroups.

What’s funny is the reverse is happening with public works. There are a few 14xx public works talkgroups popping up on the 700 MHz system (which are duplicates from the 800 system divided by 16), as public works has only just started to purchase 700 MHz radios. In other words you need to listen to the 700 MHz system for a complete picture of PD and Fire, and the 800 MHz system for a complete picture of public works.

 

[Anderegg]

SDPD just finished its rollout of the new APX8000 (single band enabled) radios, with old XTS's laying around for RSVPs and pool use etc. The APXs all have the final ENCRYPTED talkgroup zones for everything, and SDPD is preparing its version of the Sheriffs calls for service website, so any time now.

I am curious if they will eventually merge the 800MHz frequencies onto Site 1, or if they might even assign them to an independent site for use by public works to free up 700 capacity.

Paul