How to identify uplink or downlink frequency from database search results in public safety UHF band

[zradio85]

I am new to this space and trying to understand the basic interpretation of codes. In particular, if TAG = "Fire-dispatch", Class station code = "RM" Repeater and mobile" input frequency is 458.1MHz while output frequency is 453.1MHz, does it mean it is 1/2 duplex and that the input frequency is transmit mobile uplink while output frequency represents mobile receive or base downlink frequency? Does the same interpretation apply if the TAG is Fire-TAC? How about if Class code changes to BM? As per Wiki ,the class code of M or B should indicate simplex, so why some columns for Input frequency are populated?

 

[mmckenna]

I am new to this space and trying to understand the basic interpretation of codes. In particular, if TAG = "Fire-dispatch", Class station code = "RM" Repeater and mobile" input frequency is 458.1MHz while output frequency is 453.1MHz,

458.x would traditionally be the input to the repeater
453.x would traditionally be the output of the repeater

does it mean it is 1/2 duplex and that the input frequency is transmit mobile uplink while output frequency represents mobile receive or base downlink frequency?

Yes.

Does the same interpretation apply if the TAG is Fire-TAC?

Depends on how the system is set up. Might be simplex, might be a repeater. Fire Tactical usually means it's not a dispatch channel, but used when units are on scene. At least that is the way it's done around here.

How about if Class code changes to BM? As per Wiki ,the class code of M or B should indicate simplex, so why some columns for Input frequency are populated?

Usually the FCC license shows this better. Often they'll license the repeater output as an FB2. The mobiles/portables get the MO class code.
Usually the license the repeater pair (FB2 and MO) and the repeater output as MO also, so it can be used simplex.

 

[zradio85]

458.x would traditionally be the input to the repeater
453.x would traditionally be the output of the repeater



Yes.



Depends on how the system is set up. Might be simplex, might be a repeater. Fire Tactical usually means it's not a dispatch channel, but used when units are on scene. At least that is the way it's done around here.



Usually the FCC license shows this better. Often they'll license the repeater output as an FB2. The mobiles/portables get the MO class code.
Usually the license the repeater pair (FB2 and MO) and the repeater output as MO also, so it can be used simplex.

Thank you very much for an explanation