City of Davis Trunked System

[RolnCode3]

The Davis, City of database shows 858.2375 as being part of the trunked system, but it's about 10Mhz away from the rest of the freqs, and isn't listed under their license.

867.7875 IS listed under their license, but it shows mobiles as opposed to base like the rest (BTW-I'm really bad at reading FCC responses, so I may be screwing this up). Anyways, question:

Should 858.2375 be dropped, and secondary, should 867.7875 be added to the DB?

 

[WayneH]

It's possible they don't have/ran out of 866 PS freqs to allocate to them, so they issued them standard 800 freqs. I've seen it done before (Some of the UC trunked systems, ie., UCSD).

-Wayne

 

[selgaran]

The 858.2375 is their old, long unused, mobile date frequency which was folded into the trunked system. It is licensed under WNXK218, which lists "Associated Callsigns WQAJ611" (the main trunked system license).

Apparently there were only 4 NPSPAC freqs available in the area. If you hit the system development link on the page, lots of interesting info there.

867.7875 is a low power simplex channel, probably fireground tac.

 

[mstr3ttcmp]

davis city trs

hey - iv been following the new city of davis trs system for a while now and i have these talk ids that no one else i know has - i know that they work iv heard them used by fire :::

Davis Fire -- 44368
FIRE TAC 1 -- 44400
FIRE TAC 2 -- 44432
FIRE MA 1 -- 44464
FIRE MA 2 -- 44496

 

[northzone]

Yes, 867.7875 is simplex fireground tac. Limited to 6 watts max.

 

[pfish]

Looks like talkgroup 44240 is Davis PD, digital talkgroup.

Can't confirm since I don't have a digital scanner, however when the old PD channel (159.0900 GOLD) keys up, the talkgroup also keys up.


Guess its time for a digital scanner...

 

[RolnCode3]

You sure it's digital?? The system says analog. I just drove thru yesterday and searched and didn't hear a single group. I did hear the conventional PD freq though.

 

[pfish]

Yup, its digital. I submitted info that it was a mixed digital/analog system awhile back but somehow "selected talkgroups use analog encryption" -- there is no encryption that I know of on this system.

Talkgroup 44240 is Digital, and is the PD channel (the old GOLD)

Selected fire talkgroups will be digital also. I just went to radioshack and got a Pro-96...sure enough, it works

 

[RolnCode3]

Dunno if you saw this before:

http://cityofdavis.org/pw/CIP/cip.cfm?cip=802EED3B-44DA-4FEE-95EA1290E35DBE8D

Anyways, I went thru the whole thing and saw no mention on it being P-25, but maybe I just missed it, or they didn't include it in the Mot proposal. Interesting info though.

It's written into the RFP though. Kind of strange.

 

[WayneH]

Normally digital and analog TGs are broken down into the 8 block assignments, like which Type I used. The format can be adjusted but I have not seen it yet. So seeing that unknown "digital" talkgroup close to an analog fire one is a little tough to believe. Also, digital and analog encryption (aka SecureNet) can't coexist on the same network. So it's either one or the other.

Are you saying you can receive that digital talkgroup with the 96?

-Wayne

 

[selgaran]

There is NO encryption on the Davis system.

It is a mixed mode analog & P25 digital system. There are two reasons why it is not all digital: 1) none of the neighboring mutual aid agencies with 800 equipment are digital capable (UC Davis and West Sacramento); 2) all digital just cost too darn much. The decision was made to install a fully digital capable "backbone", and use a mix of digital and analog field equipment to save money.

I believe the intent is to eventually move to a fully digital system in the future if UC Davis and West Sacramento go digital.

The patch between the PD Dispatch 1 TG and 159.090 Gold channel is temporary until the police cutover is complete, probably thru the end of the week. They've been issueing portables to the various shifts and working on vehicle installs.

 

[pfish]

Yup. They installed more mobile radios today, and a few on the motorcycle traffic units.

The talkgroup for Davis PD is 44240, and it is digital.

 

[mstr3ttcmp]

wait - so if its digital then will i need to get the pro-96- or will the pro-95 work to hear police and fire and all on trunked in davis
cause all im getting on the 95 in davis right now is that grinding noise like the control channel when pd talks on gold - (159.09)


mstr3ttcmp@yahoo.com

 

[pfish]

wait - so if its digital then will i need to get the pro-96- or will the pro-95 work to hear police and fire and all on trunked in davis
cause all im getting on the 95 in davis right now is that grinding noise like the control channel when pd talks on gold - (159.09)


mstr3ttcmp@yahoo.com

Almost...its a mixed digital/analog system, so only selected talkgroups use digital. From the looks of it, they are going to use Digital for the PD, but stick with analog on the main Fire channel.

For right now, 159.0900 transmits on the digital talkgroup 44240. Thats just beacuse they are just cutting over to the new system, the patch will be removed soon, and you will need a digital scanner to get PD.

 

[RolnCode3]

But according to the Motorola documentation on Davis's website, the Fire Dept will be carrying digital radios, so they could always create digital talkgroups for the Fire Dept. It's most likely for the purpose of talking with the PD, but you never know (Arson Investigators for example). Anyways, just a point.

Also, the Motorola documentation lists the talkgroups that they created (at least what's suggested...). There are 20 TGs listed (or thereabouts). Someone may want to go thru and see if that's what it ends up being.

 

[mstr3ttcmp]

yeah i just went over the final attachments on the city of davis site - it looks to me like it will be a mix of anolog/digital eqiptment - they are buying apco 25 capable equiptment that will be progressively programmed for digital setups as west sac and ucd and the other surrounding areas progress to project 25 as well - so it looks like i will need to get the pro96 after all- but just one more question- can anyone pick up voice on the davis trunked system from the pd talkgroup 44240 when gold is used on the pro96 unlike the pro95 ?????????? :?:

yeah but right now davis pd gold channel i just patching over to 44240 - but i think that that will not last long and then u will need a digital scanner... :roll:

 

[pfish]

can anyone pick up voice on the davis trunked system from the pd talkgroup 44240 when gold is used on the pro96 unlike the pro95 ?????????? :?:

Yes. It comes in fine under digital on my Pro-96.

 

[selgaran]

But according to the Motorola documentation on Davis's website, the Fire Dept will be carrying digital radios, so they could always create digital talkgroups for the Fire Dept. It's most likely for the purpose of talking with the PD, but you never know (Arson Investigators for example).

For Police and Fire, about half of their TGs will be digital. The last fleet map I saw showed a mix of analog and digital tacs and special use TGs for both. Public works and citywide disaster TGs are all analog.

There looked to be something like 55 TGs in the entire fleetmap, many of which are are probably future expansion or infrequent use.

 

[pfish]

What attachment is it that shows the talkgroups? I haven't found that so far..

 

[RolnCode3]

This is what I was looking at, but from what selgaran is saying, it may be outdated info. Just what I found while digging. BTW-The talkgroup structure is on page 59.