Richard Clark wrote:

One source of error in the VHF/UHF region was that the rubber gasket
inside the N connector (and for that matter, for any N connector) will
accumulate thread debris. It should be used as a visual correlative
to the amount of similar debris bridging the Teflon insulator. This
debris can whack out these meters and degrade connections.

73's
Richard Clark, KB7QHC

Thank you, Richard, for pointing that out. As Perfect Tommy (Jeff
Goldblum) said in Buckaroo Bonzai, "If it was a snake, it would have bit
me". I've noticed the residue before, but never thought about it. I'll
pass that on to our local VHF and up club, The NLRS.

tom
K0TAR