SAFE-T Technicial Question

Status
Not open for further replies.

K9WG

Member
Joined
Nov 12, 2010
Messages
1,366
Reaction score
2
Location
Greenfield, Indiana USA
A question from a real ignorant person ;)

If a SAFE-T tower or towers go down will the mobile/portable units switch to point-to-point? I know our analog trunk system at work will go simplex of we lose our repeater.
 

kb9sxk

Member
Joined
Jan 27, 2005
Messages
368
Reaction score
1
Location
Southern Indiana
A question from a real ignorant person ;)

If a SAFE-T tower or towers go down will the mobile/portable units switch to point-to-point? I know our analog trunk system at work will go simplex of we lose our repeater.

there are "Talk Around" channels programed in the radio. They are not really talk around, but are simplex.
 

pickles37

Member
Joined
Dec 19, 2002
Messages
221
Reaction score
2
According to my understanding, if a radio cannot find a tower to associate with, it will simply not work (I asume will give a reject beep on transmit). There is a single SAFE-T simplex channel available, plus the ICALL/ITAC national interoperability repeaters (which are not guaranteed to be switched on), but using these would require all users to coordinate and switch to the right channel on the radios.

If the tower is up but the links between the tower and other tower sites goes down, the site will go into something called "site trunking" where it behaves like a normal trunked system (without any interconnectivity with the rest of SAFET)
 

jamesa53

Member
Joined
Mar 20, 2009
Messages
627
Reaction score
3
Location
IN
Ive never heard anything on this freq in Vigo County
 

rdale

Completely Banned for the Greater Good
Premium Subscriber
Joined
Feb 3, 2001
Messages
11,380
Reaction score
6
Location
Lansing, MI
That would mean either 1) you weren't listening when the system went down 2) the system hasn't gone down to a point where they needed to or 3) they used it but you were too far away.
 

jamesa53

Member
Joined
Mar 20, 2009
Messages
627
Reaction score
3
Location
IN
That would mean either 1) you weren't listening when the system went down 2) the system hasn't gone down to a point where they needed to or 3) they used it but you were too far away.

You must have one great antenna to hear it from Michigan. Why don't we state the obvious?
 
Last edited:

usswood

Member
Joined
Nov 1, 2004
Messages
1,405
Reaction score
180
Location
Terre Haute, IN

dwh367

Amateur Radio Operator
Joined
Mar 17, 2003
Messages
511
Reaction score
125
Location
Owensboro, KY (Daviess County)
yes my friend. This is the licensed user. We know this. Never did not know this.

The post stated that a department was using this for MDT traffic. This user would be the unlicensed one.

855.23750 WNQU951 RM 192.8 PL T/A 800Mhz Talkaround FM Interop

So, thanks for eye roll CPT Obvious.

You're welcome. To quote from an email from the IPSC dated 1/21/09: "That frequency has been discovered to be in use in the system, therefore it is not a valid talkaround channel."
 

pickles37

Member
Joined
Dec 19, 2002
Messages
221
Reaction score
2
You're welcome. To quote from an email from the IPSC dated 1/21/09: "That frequency has been discovered to be in use in the system, therefore it is not a valid talkaround channel."

That's interesting. So is IPSC saying that the SAFET t/a should not be used now?
 

kb9sxk

Member
Joined
Jan 27, 2005
Messages
368
Reaction score
1
Location
Southern Indiana
You're welcome. To quote from an email from the IPSC dated 1/21/09: "That frequency has been discovered to be in use in the system, therefore it is not a valid talkaround channel."



Now THAT is interesting news.

Do you have that email? Can you post a redacted copy or PM me about it. I have that freq in 450 radios. I never got that email.
 

DiGiTaLD

Member
Joined
Aug 10, 2005
Messages
787
Reaction score
106
855.2375

I'm reviving an old thread here reference the statewide simplex talkaround channel, 855.2375 MHz PL 192.8 Hz.

First, I can't believe they didn't know it was in use in the system. It has been a voice channel on S01 INDY since, well, seems like forever now. Even so, that wouldn't necessarily preclude it from being used anywhere in a short-range simplex talkaround application, which is exactly what it was intended for.

True, it wouldn't be very usable close to the east side of Indianapolis (where the site is) but elsewhere it would be fine. As a matter of fact, I used to hear it used quite frequently here in the northwest part of Johnson County by public safety working at local high school football games in the fall. That would actually put it well within the footprint of the INDY site, although radios on simplex within a couple hundred yards of each other could easily cover up any traffic from the site.

This used to be one of the bottom voice channels of the INDY site, and it didn't get too many channel grants. Now that rebanding has occurred, it is seeing much more frequent use by the site since everything is now below 860 MHz. That said, I'm still keeping it programmed in my conventional list with PL 192.8, as I have a sneaking suspicion that there are still hundreds of radios in the field with this frequency still programmed, and there probably will be for some time to come.

Additionally I haven't removed any of the non-rebanded NPSPAC conventional channels either. Even though all the NPSPAC repeaters are now rebanded statewide, I still occasionally hear simplex traffic on the old NPSPAC channels, and its legitimate NPSPAC, since it has the 156.7 Hz PL.

I take it 855.2375 PL 192.8 is no longer being programmed or advertised by IPSC as a statewide talkaround?
 

pickles37

Member
Joined
Dec 19, 2002
Messages
221
Reaction score
2
I don't have any "on the ground" information but the 2011 IPSC Statewide Communications Interoperability Plan (available at IPSC: Home) still lists "NPSPAC-TALK AROUND" as a valid "Mutual Aid / Interoperability Option" on p14
 
Status
Not open for further replies.
Top