Lacking a 43 ohm resistor in my current stash, I soldered two 22 ohm resistors in series temporarily to verify there is no issue with the BNC ground side. That part is OK, no loss of signal when I wiggle the connector, but there is definitely more ringing looking at a fast pulse. I suspect this is due to the additional inductance caused by stringing two resistors together. Would not the additional length of adding a stranded wire cause a similar artifact?