Thanks Jim and Frank. Yes, bonding not grounding. Thanks for the correction. I know better but got lazy with the terminology!
73, Bob K6ZZ Sent from my iPhone >> On Mar 25, 2020, at 7:44 PM, donov...@starpower.net wrote: > > Hi Bob, > > Bonding (not grounding...) coax to the bottom of a tower helps to > divert lightning currents from the coax shield to the ground system > at the base of the tower > > Bonding coax to the top of the tower helps to equalize the voltage > between the coax and the tower face. This helps to avoid pin holes > in the coax during a lightning strike. > > Bonding all coax, control cables and all other external wiring to the > a ground system at the entry to your shack forces the voltages on all > of those those cables to be equal. > > None of this is related to common mode suppression. That is best > accomplished by a choke near the feed point of the antenna. > > 73 > Frank > W3LPL > > > > From: "Bob K6ZZ" <bob.selbr...@gmail.com> > To: "topband" <topband@contesting.com> > Sent: Wednesday, March 25, 2020 10:24:11 PM > Subject: Topband: Feedline Grounding and Feedline Chokes > > Folks, > > I see a lot of references to grounding coaxial feedlines at the top of > towers, bottom of towers, and at house entry points. Is this purely for > static and lightening protection purposes or does it also help mitigate > Common Mode problems as well? > > If feedlines are well grounded, are chokes still useful for controlling > Common Modes problems? I suspect that both can be used, and should be > used, in a well designed station. > > Are there specific recommendations on the use of chokes on grounded > feedlines? Does placement matter? > > Thanks, Bob K6ZZ > _________________ > Searchable Archives: http://www.contesting.com/_topband - Topband Reflector _________________ Searchable Archives: http://www.contesting.com/_topband - Topband Reflector