Noise Burst from MTR2000?LTR

[2wayfreq]

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.

[Dan562]

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?

[2wayfreq]

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.