[FedCom] So Cal Justice System - An Alternate View
Chris Parris
[email protected]
Sat, 17 May 2003 00:23:24 -0400
I recently had a chance to spend some time down in the San Diego area and=
was anxious to try and hear for myself some of the weird and wacky comms
that have been described on the FEDCOM list by Scott, a.k.a. T. K.
Ruffzarf. After a week in the area, I have come up with some personal
theories about what is being heard.
First off, I do not believe that this system is running any kind of exoti=
c
digital mode other than Motorola ASTO IMBE, APCO Project 25 compliant
digital. I monitored these frequencies with the BC-250D scanner with the
APCO-25 digital board, and heard both clear P25 and / or encrypted P25
digital on all these listed frequencies. I have looked in to the "Seneca"=
encryption that has been mentioned by Ruff, but the Motorola & Harris pre=
ss
information seems to describe "Seneca" as the model name of the new line =
of
radios, not a digital encryption standard, (There is a European project
involving Motorola called SENECA, but it involves voice recognition in
automobiles).
Secondly, I can't be sure this is a trunked system. I searched from one e=
nd
of the VHF spectrum to the other and was never able to hear anything that=
even remotely sounded like trunking control data, or any other kind of da=
ta
(other than DES on known Customs frequencies or paging data). I tried all=
the frequencies that were posted as "controllers", but never heard a peep=
.
I did do searches in very small steps, as recent posts from Ruff seem to
indicate some strange channel steps might be used (165.270 and 172.020 an=
d
172.030 were listed), but nothing unusual was found.
I searched the bands using several radios, including the BC250D, the
Optoelectronics Optocomm radio and an Alinco DJX-10. I also sat a various=
locations around the San Diego County area, including Point Loma, Cabrill=
o
National Monument area, Mission Valley, El Cajon and the Alpine area.
Again, no sign of any trunking data was heard. =
Another interesting question is the sheer number of frequencies that seem=
to be used. In preparation for this trip, I started a spreadsheet of the
frequencies that had been posted here that were alleged to be part of thi=
s
system. Although I'm sure I only caught some of the posts, there were clo=
se
to 200 unique frequencies listed. The major technical benefit from using =
a
trunked radio system is the efficient use of radio spectrum. You are
supposed to be able to fit maximum users in minimum radio frequencies. Th=
is
system, if trunked, would appear to be going the wrong way - a maximum
number of frequencies with an apparently small number of agencies!
I will freely admit that I have no idea of how this system is set up as f=
ar
as inputs, outputs, transmitter locations, and channels. There are many
active frequencies that seem to be involved in this, but since they are
mostly encrypted and the users or purposes can't really be discerned, it'=
s
still a guessing game. I can confirm that some of the un-encrypted
communications that were monitored sounded like Border Patrol operations.=
But since I heard only ASTRO IMBE digital comms, I honestly don't think
that the digital part of the system is somehow unique in requiring multip=
le
repeaters inputs or outputs for it's operation. Public safety radio syste=
ms
around the country are using the same digital modes without any unusual
requirements for multiple simultaneous repeaters. However, those of us wh=
o
are old enough to remember the older Border Patrol radio system, which di=
d
have repeaters feeding in to other repeaters, one could often hear a Bord=
er
Patrol unit talking in to 4 or 5 repeaters at the same time for wide-area=
coverage.
Even with the previously mentioned FEDCOM frequency posts, I can only
confirm about 40 or so active frequencies that I believe are part of this=
San Diego area system. I could not confirm that many different frequencie=
s
were all activated with one input. I was searching through the listed
frequencies and when one came up active, I did not hear others come up at=
the same time. Also, when one frequency did become active, that frequency=
seemed to stay active with that particular conversation until it was
through and not hop over to another frequency as you might expect on a
trunked system. When I was able to catch an un-encrypted radio talking wi=
th
an encrypted radio, the back-and-forth comms would stay on that frequency=
for the duration. =
So, here are the frequencies that I found active with digital comms durin=
g
my searches, along with any notes on what was heard. P25 means un-encrypt=
ed
APCO Project 25 compliant digital comms; ENC means encrypted P25 digital
comms:
143.2750 P25 Military, probably not part of "Justice
System" =
162.7000 ENC
162.8500 ENC =
163.6500 ENC =
165.0625 ENC =
165.8250 ENC =
165.8750 ENC =
165.8875 ENC Busy =
165.9125 ENC Busy =
166.8750 ENC =
166.9125 P25 Un-encrypted digital heard =
166.9500 ENC =
167.1500 ENC Strong @ Mission Valley =
167.2250 ENC =
167.2375 ENC Strong @ Mission Valley =
167.3625 ENC Busy =
167.3750 ENC Busy =
167.5250 P25 Un-encrypted digital heard =
167.6000 ENC =
167.7250 ENC =
167.7875 ENC =
168.5000 P25 / ENC Suspected Border Patrol P25 =
168.8250 P25 Un-encrypted digital heard =
169.3000 P25 Transportation Security Administration @
SAN (input) =
169.6375 ENC =
170.0625 P25 / ENC Un-encrypted digital heard =
170.6750 ENC Busy =
170.7500 P25 Un-encrypted digital heard =
170.9125 ENC =
171.1750 ENC =
171.2625 ENC Busy =
171.3375 ENC
171.4375 ENC =
171.5125 ENC Busy
171.6375 ENC =
172.0250 ENC =
172.2875 ENC =
172.4000 ENC Busy =
172.5125 P25 / ENC Busy =
172.9000 P25 Transportation Security Administration @
SAN (repeater) =
173.3500 P25 Un-encrypted digital heard
173.4500 P25 / ENC Confirmed Border Patrol P25 =
173.4625 ENC =
173.6625 ENC =
173.9750 ENC Busy =
So, that is all I have to offer on this subject so far. I plan on making
some further trips to the area to try and see what else I can find, but f=
or
the time this system seems to remain a mystery, but perhaps not as
mysterious as has been previously reported.
- Chris
--
Chris Parris
Beaverton, OR
[email protected]
www.groups.yahoo.com/group/pdxmilcom
wwwlive365.com/stations/cparris2