At my nav station I have a bus bar with jumpers between the connectors
to provide NMEA data to a variety of equipment which wants to see info
such as lat/long. It provided a nice way to connect multiple pieces
of equipment to a single NMEA output. The problem seems to be with
the data output from my SR161 AIS receiver. I have the AIS data going
to single set of connectors on the bus bar which are bridged to the
cable which goes to my RayMarine C80 chart plotter. All of the above
cables have large ferrite chokes on both ends.

When I connect the cable to the SR161 AIS receiver, the VHF radio
which is located very near the above equipment receives static on
occasion. By this I mean that I hear random periods of static on the
radio which disappears only when I turn the squelch up quite high. If
I unplug the data cable from the AIS receiver, the static disappears.

How can I shield the bus bar so that I can distribute the data and
bridge the AIS data such that I don't generate RF which interferes
with the VHF?

-- Geoff