dual control,
As i have previously stated, i am not familiar with this set so can only surmise.
Lots of radio equipment performs a BIT test when powered up which tests all the circuits within the radio. This test may momentary activate the transmitter stage of the radio to see if it functions correctly. If there is a miss match between the radio and the antenna system the test will fail. Best to power up with a 50 ohm dummy load connected if not sure.
Unless you know what you are doing with this equipment i suggest you leave it to trained tech as you can cause lots of expensive damage otherwise.
Regards
Peter