Tuning issue above 2740MHz?

[NotherNgineer]

Above 2740MHz, it seems that one cannot transmit on one PortaPack and receive on the other. One unit is H2R4+, and the other is H2R4+/r9.

I don't know yet if it's a transmit or receive issue, or specific to my units. Can anyone do this successfully?

(There is a lot of noise/birdies picked up above 2740MHz, but probably all internally generated since it shows up even with the antenna removed and an SMA terminator installed.)