new bedford fire question

[KB1UAM]

I hear all the time when the Fd dispatch says go to channel 16 but they are on channel 1 on 470.5125 still,also when the apparatus says they are now on channel 16 but technically they are still on channel 1. Could this be some kind of mobile repeater or is it a simplex channel?

 

[zerg901]

KB1UAM you seem to be saying that when units go to Ch16 you still hear them on Ch1. That very well could be a "mobile repeater" (MO3) system. Do you see any MO3 listed on any NBFD radio licenses? They might have their portable radios programmed to transmit on 460.5375 and receive on 470.5125 for Ch 16. In this case, they could have a MO3 programmed to receive on 460.5375 and transmit on 473.5125.

 

[garys]

It's probably Ch 1 on simplex. Mobile repeaters are generally not used in urban systems. Since you're in New Bedford, depending on where you are, what type of antenna you're using, and where the apparatus is, you might hear them pretty well. Some of that would also depend on whether they are using portables or mobiles.

 

[ecps92]

Gary, don't forget many of the Depts program 1 and 16 identical [UASI, BFD etc]
so the user can go to either end of the stop dial and still be on the Primary Frequency

It's probably Ch 1 on simplex. Mobile repeaters are generally not used in urban systems. Since you're in New Bedford, depending on where you are, what type of antenna you're using, and where the apparatus is, you might hear them pretty well. Some of that would also depend on whether they are using portables or mobiles.

 

[garys]

Gary, don't forget many of the Depts program 1 and 16 identical [UASI, BFD etc]
so the user can go to either end of the stop dial and still be on the Primary Frequency

They do, but I don't think that's the case here. As it was explained to me, that is actually a NFPA thing with the logic being that in a panic a FF (or anyone else) can simply turn the dial to either end and send a MayDay message. The latest iteration of our non FD radios doesn't have that. I'd have to look at the radio to refresh my memory, but I think Channel 16 might be the MassPort UHF channel. Channel 1 is Tac 1, which will be our "new" dispatch channel when we narrowband.

 

[ecps92]

-k Thanks

They do, but I don't think that's the case here. As it was explained to me, that is actually a NFPA thing with the logic being that in a panic a FF (or anyone else) can simply turn the dial to either end and send a MayDay message. The latest iteration of our non FD radios doesn't have that. I'd have to look at the radio to refresh my memory, but I think Channel 16 might be the MassPort UHF channel. Channel 1 is Tac 1, which will be our "new" dispatch channel when we narrowband.

 

[KB1UAM]

KB1UAM you seem to be saying that when units go to Ch16 you still hear them on Ch1. That very well could be a "mobile repeater" (MO3) system. Do you see any MO3 listed on any NBFD radio licenses? They might have their portable radios programmed to transmit on 460.5375 and receive on 470.5125 for Ch 16. In this case, they could have a MO3 programmed to receive on 460.5375 and transmit on 473.5125.

Yes I do see several frequencies listed as MO3

 

[zerg901]

The MO3 can be used in a couple of different ways. One way is as a link back to the dispatcher. A 2nd way is as onscene repeater that extends the range of radios around the scene. I suppose that a third mode could be a combination of the 2 previous modes. A 4th mode could be to serve as a temporary remote receiver site for the main FB2 system. New Bedford might be using this 4th mode. (Some agencies use MO3 to link radios from different bands - like Essex County Mass - they link their VHF FG channel to their UHF FG channel).

I am pretty sure that Providence RI FD and Portland ME FD have repeaters on all of their fire trucks. Maybe Washington DC also. I have been told that Anne Arundell County in Maryland has 1 fire truck in every station equipped with a mobile repeater.

 

[KB1UAM]

Yes New Bedford just installed this mobile repeaters on all their trucks in the past year, they did this through a homeland security grant, we have an industrial park in the far north end of the city and radios have fairly hard times getting into the repeater, without the mobile repeaters turned on they can barely hear each other. when they go on a radio box call the dispatcher tells engine 5 to turn on there mobile repeater and go to channel 16 on there portables, and btw they carry XTS1500s

 

[zerg901]

Whenever you hear the dispatcher tell someone to turn on their repeater, you might want to check those MO3 freqs to see what your hear. They might use a different freq for each truck. Or maybe they just use 1 MO3 per incident.

The MO3 might operate in 2 or more modes. Lets call them "Mode 1" and "Mode 2". Mode 1 could have the MO3 set up with 465.5375 input and 473.5125 output - plus - 470.5125 input and 465.5375 output. "Mode 2" might have the MO3 set up with just 465.5375 input and 473.5125 output.

Mode 3 could even be 465.5375 input and 470.5125 output for the MO3.

And I bet that there are more "Modes" that can dreamed up.