In reply to OK2BWB:
I measured it using a directional coupler, differences related to real
50ohm are not negligible - even at a factory tcvr!
This is very true and seldom appreciated. It becomes apparent if you use an antenna current meter, that very few transmitters have an output impedance of anything like 50 Ohms. Quite funny then that we spend so much time and (often wasted) effort in getting the VSWR low.
73 Richard G3CWI