Batboard

Its been awhile since someone has reported on the new(er) LAPD system. Anyone know how it is going, etc?

I can still tell you that, alot of officer are still complanning about the APCO system, and having hard time still talking to the air unit.

What type of specific problems are they having talking to the air units ?


Mike

In the millions of dollars that Motorola made in this deal they failed to come up with a good soloution for the air units. There is no current radio for them that will communicate to the ground units from what I was told.

How did the old comm system work? Did it go thru a repeater or was it a "Tac" channel which was simplex? I would imagine that it would be simplex, however the distance involved from air/ground can't be much. What exactly is the problem?

there actually is a apco25 air unit available that covers all of the bands but the problem is that right now practically every us govt. agency is getting all of them first due to the 9-11 incident.

I find it hard to believe that they can't
adapt an Astro Spectra for air operation.
They've got 72 volt railroad versions, and even six volt motorcycle versions. Setting up a radio for 24 or 28 volt operation or 400 Hz power isn't exactly rocket science.

Elroy

it is interesting to note that there is a timing adjustment in the RSS in ref to "astro modulation" that, when adjusted, gives an RSS generated warning that "this should not be adjusted unless the vehicle will travel faster than (i think) 160 kph.."


LOL...

they can make it work, especially on a helicopter that's travelling around 80-100 knots and in some cases, HOVERING...

doug

San Diego County's ASTREA uses a Spectra radio so there is no issue with putting them in (Other than the doppler effect and I'm unsure why they didn't make the change in the programming). From what I read LAPD was so hell-bent on getting ASTRO Sabers to work. Why is it so hard to buy some Spectras?

<font size=-1>[ This Message was edited by: Twisted_Pear on 2001-12-08 01:27 ]</font>

Twisted_Pair, they must be killing you! You should really see a Urologist.

Sorry for the pun! It's the silly season!

Happy holiday's.

Hi Y'all,

I wonder if the problem is FAA related, rather than radio related? I'm in the CAP, and we've had fits trying to find radios that were not only NTIA compliant (a separate issue!) AND acceptable to the FAA for install in our aircraft. I would imagine that finding a digital (P25) radio might be even harder. Apparently the FAA has become a lot more hard-nosed in recent years about the installation of "non-approved" radio equipment in aircraft.

Any thoughts?

Hartley

I would suspect that this is the case. I'd be willing to bet that they first need to check with the maker of the aircraft to insure that there aren't any compatability issues (like eletrical, interference, RF etc) with any of the other systems in the aircraft.

Folks in the aircraft business are very touchy about that kind of stuff, because all it takes is one small problem in the air to become a big one.

Metro Nashville's air units are working as well as the rest of the units, but I'm sure its on a smaller scale than LA. There are groups that are purely analog on the system, but those are due to financial situations, not technical ones. (Except the MDTs). So I would guess thet LA's air problems are not regulatory as Nashville's choppers are pretty busy and communicate as well as can be expected. However, I'm sure most of you know that IMBE is not very tolerant of background or wind noise. It's not even capable of carrying an alert tone with any fidelity,so that may be a problem with some air operations.

Wolfsburg makes an fully APCO 25, IMBE compliant aircraft radio. So there is no excuse for the air units not being able to talk with the ground units in digital format.

Dan...

Yes, but how many actual public safety users across the nation are using APCO-25 radio equipment in digital mode to communicate from airborne platforms?

Doppler Effect?
Wind / Background / Engine Noise ?

All of this has a serious effect on APCO-25 digital signals, and reproduction of background noise in these environments is extremely difficult at best.

Just look at how the DEA/FBI/Customs operates from airborn platforms - they very rarely use DES/XL and ASTRO from those platforms.....

_________________
Lindsay C. Blanton
The Trunked Radio Information Homepage
http://www.trunkedradio.net
[email protected]


<font size=-1>[ This Message was edited by: blantonl on 2001-12-10 13:00 ]</font>

dan, Lindsay


As I mentioned in a previous post on this same thread the problem is that all of the U.S. govt. agencies are buying up all of the Wulfsberg apco25 avionics radios. Test were run in August of this year with LAPD air units and the apco25 air radios had no problem talking with the ground units, unfortunately there was only one radio for these tests and it was a loaner that then went to a unnamed govt. agency after the LAPD test. It comes down to the 9/11 incident again, all u.s. govt. agencies get first buying rights.


Mike

Mike, thanks for this follow-up =-- very interesting news.

I'd also bet that these Wulfsburg radios are probably a tad bit more expensive then the average ASTRO Spectra!

Anyone have a picture of one of tehse "Wolf" units?

If you have ever seen a Wulfsberg C5000 control head and the RT5000 radio unit that does 29.7 to 960MHz AM and FM then it is the exact same size and same package only redesigned for apco25 in the 138 to 174, 406-520 and 806 to 870 bands. Basically the most used public service bands have P25 added now. Yes it is a bit more expensive than a spectra but lets face it all TSOd avionics packages are a lot more expensive than land mobile units. The end user is basically paying for all of the months of FAA and foreign government testing and the stacks of documentation that it takes to get the radios certified for avionics use not just by the FCC and FAA but also the majority of foreign agencies that are usually more stringent than the ones here in the U.S.


Mike

An issue with Spectra and SmartZone is that users have to switch to SIMPLEX to talk to the air unit. Using trunking with the air unit is a no-no due to frequency reuse and co-channel interference.

The comments so far posted are very interesting. This air-to-ground police comms seem to be a common problem.

SmartZone and Smartnet radios are commonly installed and used in public safety aircraft. Sometimes system designers will install special sites that don't reuse frequencies. The SZ or SN radios would then be configured to only use these special sites. I don't believe that Wulfsberg does trunking.

the wulfsberg radio does everything that the standard xts3000 does, trunking in all bands vhf/uhf and 800 smartzone omnilink etc.


Mike

Hi everybody,

Another reason probally they dont want use Astro Spectra in the Air unit and Patrol cars too was because, they needed that 450-512 band split, that what I was told, and Astro Spectra, didnt cut it. And also it had to do with the FAA regulation too.

That all I heard from people here in LA