Originally Posted by
aardvark2zz
It's 0 ohms near 0 Hz (DC) but once you get to a few hundred KHz the impedance is much higher. Don't forget that you have real and inductive impedance which 'add' up. 400W into 50 ohms is only 2.8A rms.
Maybe you've never seen the battery cable sized conductor from the center conductor of the coupler mount to the tail structure. That wouldn't be needed if the currents were low. The purpose of the current-fed antenna coupler is to convert 50 ohm impedance signal to near zero ohms - at operating frequency. That means currents up to hundreds of amps. And, yes, the carbon in a carbon fiber structure can mean mischief.
The HF system was undoubtedly thoroughly tested at A/B, but how about with all the combinations of degraded bonding?
BTW, what is 'real' impedance?
GB