There has been some discussion on this and other sites about unique antenna connections on certified Part 15 transmitters. Here is what the FCC actually says on this matter:
"The manufacturer may design the unit so that a broken antenna can be replaced by the user, but the use of a standard antenna jack or electrical connector is prohibited. This requirement does not apply to carrier current devices or to devices operated under the provisions of §15.211, §15.213, §15.217, §15.219, or §15.221."
John WDCX your post clears up doubts I've had about Part 15 AM transmitters, some of which have RCA antenna jacks. I've often wondered if this was proper.
But we still need to consider unique connectors for 15.239, Part 15 FM, which evidentally means the standard F-connector on one popular transmitter is only legal if it's not used.