[TowerTalk] Antenna swithcing system for M/S stations

[Yo3ctk]

I'm looking to build or buy an antenna switching system suitable for a M/S 
station. What I really need is some ideas about the configuration. Minimum 
requirements are:
- 12 antennas
- 2 transceivers
- possibility to connect any to any
- possibility to interdict some switching configurations, programmable
- 1.5 kW capable

The main reason for requirement #4 is due to the fact that one of the 
antennas is a F12 C4XL, tribander+40m with two feeders. Obviously a 
configuration like RUN on tribander + MULT on 40m section is not possible.

I looked into the obvious configuration, a relay matrix 2 rows/12 columns, 
with some wired or programmed logic. The problem I see is due to 12 open 
contacts in parallel with a few picofarads capacitance each. I calculated an 
unacceptable crosstalk between RUN and MULT stations. Even with band filters 
in line, with one station transmitting and the other receiving, the 
interference will be enormous.

But maybe there are other solutions. Please let me have your thoughts. 
Thanks,

73 de Mike, YO3CTK
YR7M team