Batboard

Has anyone ever heard a noise burst emit from a MTR2000 repeater in an LTR UHF system that sounds like a freight train. It occurs only when a unit is accessing the system and another signal of higher signal strength is present. That signal does not have to be the RX frequeny of the repeater.

Two things come to mind:

If you're using EF Johnson subscriber products with a /\/\ MTR2000 Base Station Repeater, you've got incompatibility problems with CTCSS / PL Reverse Burst. /\/\ uses 120 degrees for their PL Reverse Burst and EF Johnson uses 180 degrees for their CTCSS Reverse Burst. This creates 60 degrees of open noise on CTCSS / PL phase shift for the Reverse Burst signaling.

There's also a possibility that repeater site is prone to Inter Modulation Distortion IMD which is a mixture of two or more transmittered frequencies creating a third unwanted RF signal. I wonder if you ordered the External Double Circulator Operation Option X676 and the High Performance Preselector Option X265 for that MTR2000 station?

Thanks Dan,

The problem is basically more of an annoyance than a system impact. Just kinda looking for the root cause and possible solution. Thanks for your insight.