|
Grex > Radio > #8: Public Safety / Police / Fire monitoring. | |
|
| Author |
Message |
wjw
|
|
Public Safety / Police / Fire monitoring.
| 
Jul 18 22:01 UTC 1998 |
Hi folks. My interest in radio is mainly from the point of view of
monitoring (ie with a scanner). I just got the news that Pittsfield Twp.
(where I live) is moving to a new "800 mhz" public safety communications
system. Well, I decided to look for them in the 800 mhz range, and
except for cellular (in approx 860-920 mhz range) everything I heard
(mostly around 815 - 825 mhz) seems to be digital transmission,
and therefore unintelligible on an ordinary receiver.
Can anybody shed any light on this? Are the days of monitoring
police / fire / public safety quickly coming to an end?
Also, any other discussion on scanning / monitoring welcome!
|
| 44 responses total. |
goose
|
|
response 1 of 44:
|
Jul 21 18:04 UTC 1998 |
PT is part of the countywide trunking system I do believe.
|
wjw
|
|
response 2 of 44:
|
Jul 22 17:33 UTC 1998 |
Thanks, and please excuse the next question - is the countywide
trunking system digital and un-monitorable?
The reason I ask is because there is a section in "Police Call"
entitled "You *can* monitor trunked systems" along with a detailed
explanation that I did not quite understand.
|
n8nxf
|
|
response 3 of 44:
|
Jul 23 11:14 UTC 1998 |
Radio Shack sells a scanner designed to monitor trunked systems I seem
to recall. I use to monitor the AA Police trunked system on my scanner
simply by programming in the 10 frequencies and scanning them. I would
have to lock out the data channel of the day since that is just a bunch
of digital noise. Occasionally I would also have to skip other channels
when they were sending data over them. It was not a very relaxing task
as I had to attend to the scanner a lot.
|
wjw
|
|
response 4 of 44:
|
Jul 23 17:37 UTC 1998 |
OK, next question... Is the county trunked system the same as the AA
Police trunked system?
|
n8nxf
|
|
response 5 of 44:
|
Jul 24 10:40 UTC 1998 |
The same? I don't think so. I do know that the county sheriff and the
AA Police were putting up obsolete 400' towers all over so that they could
better communicate with one another and reduce the No of dead spots.
|
wjw
|
|
response 6 of 44:
|
Jul 24 18:32 UTC 1998 |
Does anybody have the freqs. for the 2 trunked systems?
|
wjw
|
|
response 7 of 44:
|
Jul 26 13:24 UTC 1998 |
Well, after a bit of research, I can answer my own questions.
Yes, there is only one trunked system. It is officially the AA police
trunked system, but almost all pulic service agencies in the county
are now using it. Pittsfield Township was the last to switch over,
about 4-6 weeks ago. HVA is also on it, although you can also hear
them on thier old freqs. as well.
The freqs of the trunked system are:
851.0875
851.1875
851.2625
852.0875
852.1875
852.2625
853.0875
853.1875
853.2625
854.0875
854.1875
855.0875
855.1875
|
goose
|
|
response 8 of 44:
|
Aug 6 20:26 UTC 1998 |
I'll look at my trunking scanner, and let you know what the fleet map
codes are (good only if you have a trunking scanner)
|
ken
|
|
response 9 of 44:
|
Aug 22 02:34 UTC 1998 |
There are two trunking systems in Washtenaw County in Michigan.
The University of Michigan has their own system and
Washtenaw County has the other. The City of Ann Arbor
shares the Washtenaw County System. For an updated fleet
map, you can stop by our office at Communications Electronics,
Emergency Operations Center, 254 Wagner Road South in
Ann Arbor. Call me at 734-996-8888 if you need directions.
We have sold thousands of trunking scanners and it is very
easy to monitor. For more information about trunking scanners,
please visit the Communications Electronics web site at
http://www.usascan.com. You can also get fleet map information
by visiting the Bearcat radio club web site at
http://www.bearcat1.com
|
scott
|
|
response 10 of 44:
|
Oct 8 21:56 UTC 1998 |
Ann arbor's trunking fleet map is E1P2, same as what UM uses. I found a great
Web page with all the michigan info on it. I can't recall the URL, but I did
an Altavista search on "ann arbor" + "trunking", or something along those
lines.
|
scott
|
|
response 11 of 44:
|
Oct 9 00:33 UTC 1998 |
http://members.aol.com/wwhitby2/trs.html
and
http://www.concentric.net/~Lsbutler/
have some interesting info. The first link is the one I got all my info from.
|
ecl
|
|
response 12 of 44:
|
Jan 2 19:45 UTC 1999 |
This is some great info.
In just the last year I've gotten involved in scanning and right now
I am starting to flirt with ham.
I was suprised to find that some of the same poeple I've seen on grex
are also involved in local area radio.
|
scott
|
|
response 13 of 44:
|
Jan 2 20:51 UTC 1999 |
Well, if you like to use technology to communicate over distances...
|
scott
|
|
response 14 of 44:
|
Jan 3 15:22 UTC 1999 |
Ah!
I did some more poking around recently and discovered that the Ann Arbor and
UM systems now have a different fleet map than before. Ypsi is now part of
the Ann Arbor system, and other communities have been added too.
Check out
http://www.trunktracker.com
for details.
|
goose
|
|
response 15 of 44:
|
Feb 21 04:05 UTC 1999 |
Okay, I've got a BC235XLT, and on the new (and old for that matter)
fleet map listing it gives a figure of 0 and 7 for one of the
blocks. How can I enter both numbers?!? How are we supposed to
interpret this? Actually it's two of the blocks, not one.
|
scott
|
|
response 16 of 44:
|
Mar 11 19:44 UTC 1999 |
I just played with the possible combinations until the groups displayed best
matched the listings... like Ypsi using the 5 digit numbers instead of the
"400-1" style of Ann Arbor.
|
goose
|
|
response 17 of 44:
|
Mar 11 20:07 UTC 1999 |
If you make both of those blocks (I forget which ones they are)
7 ypsi will show up at 522-x I think.
|
scott
|
|
response 18 of 44:
|
Apr 18 00:28 UTC 2000 |
I've been putting "consumer" frequencies into my scanner lately.
Just for grins, here's the "Family Radio Serivces" (FRS) frequencies:
CH - FREQ.
01 = 462.5625
02 = 462.5875
03 = 462.6125
04 = 462.6375
05 = 462.6625
06 = 462.6875
07 = 462.7125
08 = 467.5625
09 = 467.5875
10 = 467.6125
11 = 467.6375
12 = 467.6625
13 = 467.6875
14 = 467.7125
|
rcurl
|
|
response 19 of 44:
|
Apr 18 03:26 UTC 2000 |
Do you know why they are in two groups 5 Mhz apart? It's just simplex,
isn't it? What's in between?
|
eprom
|
|
response 20 of 44:
|
Apr 18 11:45 UTC 2000 |
GMRS??
/
|
jerome
|
|
response 21 of 44:
|
May 3 01:58 UTC 2000 |
GMRS channels are actually interlaced (and in some cases overlap) with the
first seven FRS frequencies. The spectrum between the two bands (462 and
467) is typically used for commercial 2-way systems. Where I'm located
there are bus systems, school security, power company 2-way, and
medical dispatch, including helicopters.
|
goose
|
|
response 22 of 44:
|
Oct 20 16:35 UTC 2000 |
Anyone know anything about this new "CB" band, made up of old public
service freqs in the HiVHF band?
|
n8nxf
|
|
response 23 of 44:
|
Oct 21 10:34 UTC 2000 |
There's an item in this conference on that, is there not?
|
goose
|
|
response 24 of 44:
|
Oct 21 19:05 UTC 2000 |
Yep, I found it about 20 seconds after I posted #22.
|