Paul, thank you for responding.
I am in very cold and windy Port Townsend.
Yes a long run of coax between PA and the shorter coax from the magmount.
SWR at mag mount measures 1.0 on 20 meters. SWR at PA end of coax measures over 6.0.
Earlier I checked the firmness of connection to mag mount. It seemed fine but I have weak hands. I can do it again.
Earlier I checked whip connection to Tarheel. It seemed good, but again I have weak hands. I can do it again.
The bnc connector on the mag mount is a bit weathered. To me it would be the most suspect except that is the connection that measures 1.0 at the antenna using my YouKit meter. One thought is my reading at the mag mount is faulty but that would be pretty coincidental that I can move the coil to 1.0 on the YouKit without being able to trust it.