Programming question

[fyrmedic33]

Trying to figure out if there is a way to program multiple CTCSS tones into 2 different radios. MCS2000 and PM1500. I know MPL exists but the only problem is I can only assign 1 RX PL and the Cal Fire channels I need to assign have different RX PLs. Is there a work around for this?

 

[SteveC0625]

The very nature of CTCSS precludes the use of more than one tone at a time on a channel. It is a sub-audible tone transmitted along side the regular audio.

I am presuming that you have two different stations transmitting on the same frequency using two different PL tones. Set up two different personalities, each with their respective PL's, but both on the same RX frequency. Assign them both to the same zone. Then assign them both to the same scan list.

If you have to talk back to both of them, you'll have to pick the right personality to transmit on.

If all this is receive only, why bother with PL? Set up one personality and use CSQ instead of TPL or DPL.

 

[fyrmedic33]

The problem exist since I can program the 16 different PLs that Cal fire uses in the transmit but only 1 PL for recieve. AEU L 151.1900 has a RX CTCSS of 146.2. XAM CMD has a RX CTCSS of 123.0. And the command channels have a RX CTCSS of 103.5. My only option would be to leave the RX of the MPL to CSQ but then I'm going to get all the other traffic from the valley coming through. I'm wondering if Motorola has any kind of update that would allow me to add this. I know Kenwood makes a Cal Fire chip or program that allows the MPL with multiple RX CTCSS. Awhile back when I worked Cal Fire we used to have a box under the radio with a knob that would allow you to switch tones. Do those still exist?

 

[ramal121]

Your problem is that you need to assign different transmit PL's to access the different Cal Fire repeaters, however your receive PL needs to stay constant with the channel you're on. When you use MPL, you basically replace the the original PL assignment with what is written in the MPL list. This includes both the transmit and receive PL

Now if you use your MPL list for just one agency/ranger unit, you could put that single receive PL in each slot of your MPL list. This would not work if the radio needs to be used in another area/channel that has a different receive PL.

This is the way Motorola MPL works and also the plain Kenwood TK-790. If you get a TK-790 with the optional fire service firmware, they address this problem by switching only the transmit PL (QT) and leaving the receiving PL as it was written in the channel assignment when using MPL. That way you can move from area to area, have the correct PL for receive, and select the proper repeater to use.

Your options for a Motorola have been stated. Create a MPL list and leave the receive PL as CSQ which will allow co-channel traffic to be heard. Or make a separate channel with the correct receive and transmit PL for all repeaters and agencies/ranger units you expect to respond to. This will eat up a lot of real estate on your channel knob. Sorry but that's the choices.

An external tone box is still available and can be installed by a qualified tech, but you have to remember to set it to off when a channel that doesn't use MPL is selected.

 

[fyrmedic33]

Yeah that's what I was guessing. Thanks for replying.