Use a Line Isolator if you are getting RF in the shack. This Line Isolator is made using ferrite beads on a piece of RG-58 or RG-8X cable. For HF you should use 5 or 6 ferrite beads. Use ferrite beads # 2643540002, you can get them from Mouser using part # 623-2643540002. The beads cost ~ $.50 - $.75. They will slip over RG-58, and some RG-8X (they will not slip over some RG-8X).
I use ~ 4’ of RG-58 I put 3 groups of 2 beads (total of 6 beads) separated by small ty-wraps. I then covered the beads with shrinkable tubing. On the end of the RG-58 I put a PL-259 and on the other end I put a cable SO-259.
Completed Line Isolator
You could also put the line isolator into a PVC pipe with PVC caps. You can zig-zag the coax back and forth inside the pipe. You put chassis mount SO-239s on each end of the tube. I would use 1 1/2” or 2” PVC pipe. If you put it into a PVC pipe it will be ~ 6 - 8” long.
Antenna Line Isolator
RG-8 Line Isolator
This Line Isolator is made using ferrite beads on a piece of RG-8 cable similar to the isolator above. For HF you should use 6 or 7 ferrite beads. Use ferrite beads # 2643102002, you can get them from Mouser using part # 623-2643102002. The beads cost ~ $ 1.50 - $ 1.75. They will slip over RG-8, and I cover the cable with heat shrink tubing and PL-259s.