back to back radio configuration advice needed

[engineer10122]

I need to create a low cost repeater / coverage extender using two back to back radios.

Initially I need this for the Motorola “Passport” trunked radios network.
The mobile radios we will use are:
CDM1550LS+

Later I will need to do the same things for out digital MotoTrbo system.
The radios will be:
XPR4300s

There seems to be people selling cables to do this.
Please provide your comments and suggestions.

Thanks.
Scott

[thebigphish]

What exactly are you looking to do? In band repeat? Cross band repeat? Passport system <---> simplex channel extention? All are possible, and simply...however you need to understand that if you are going to extend a system that has trunking protocol which queries a repeater, and then grants local authorization for a radio to transmit (the keydown delay followed by PTT auth beep in passport), you will have to address the problem that the system will NOT work 100% going into the repeater, as if there is a greater than normal delay in channel PTT authorization by the controller, or a "busy bonk" from the system, your end users will NOT know, as the system is transparently duplex in the keydown state prior to the beep, as it queries the system, says yay/nay and then allows the user to talk.

Feel free to PM me, i've fought many a battle with similar systems.

[extrabh]

Back to Back Trbo is now very easy with firmware R01.04.03. I have made a digitial 450 mhz to digital 460mhz. Digital to analog with the same hooks ups you would use on a tone panel. Because the new firmware allows for pl/csq detect. I have not tried LTR or passport yet that is next.

T.

[Mikey]

I use a Pyramid Extender with my CDM1550 LS+ Passport Radio and it works really nicely. It even gives me the talk permit tone on the passport system