BNC coax T NicCard connection occasional iffy contact when..

my network card and my coaxial cable T on my home network don't always
make good contact especially it seems when they are cold ie not
trasferring data.
And such kills my LAN.
The metal connection sometimes needs to be turned ever so slightly or
just moved a tiny bit.

Happens once or twice a month.

Is there a trick to milking these components as I am not real excited
about running RJ45 to replace my coax.

I cleaned the post on the NIC with a scratchy cloth.

Thanks!