Batboard

I have 10, 900MHZ Quantar stations used in a trunking configuration. 5 are from 1999 and 5 are from 2001. I can not swap the exciter modules between these stations without causing crazy RF desense issues on the receivers........All the Quantars work fine on the bench but when connected to the antenna network and trunking controller, the 1999 radios cause desense on their RX'ers. If we put the 2001 exciters in the stations everything works fine. But the 1999 exciters cause the crazy RF problems. There is a 39MHZ split between TX-RX and they still desense their own receiver.
Has anybody seen this problem of something like it? NEWER boards are TLN3308A-CLF1520A the older boards are CLF1520A13
Thanks for any help!

Quantar exciters have firmware EPROM's on them and there is likely a firmware issue between the SCM and the exciter.