Roof rack earthing?
Posted: Thu Nov 21, 2019 6:23 pm
Hi all, just a question as per above.
I have a Land Cruiser 80 so quite a big car, it has a full length roof rack, that is it extends from the tailgate to around a foot past the front screen and is the full width of the car, so a substantial ground plane.
There is a metal wind deflector around four foot wide and 6 inches deep at the front and a new Sirio Super Carbon is bolted through that, then there is a short length of RG58 going to a bulkhead mount through the roof of the car, this then is run down to an antenna switch, the switch is used when the rack is not on and the Ariel is used on the roof so a simple changeover without going through the SWR tuning etc. I get a good SWR on the rack and seem to get a good distance, a quick test the day before yesterday showed an easy ten kilometre conversation, this was with the car facing the person I was conversing with, as the meat of my ground plane is behind the Ariel I consider this fine.
Given the rack is earthed through the Ariel mount and then through the coax to the bulkhead mount connector also earthed to the car body, is there anything to be gained by additional earthing i.e. braided earth strap from rack to car body, perhaps at the rear?
I am pretty savvy with vehicle mechanics/electrics and have used CB's for many years my installs have just been fit/test and use with no issues, so while fitting all new coax/connectors/Ariel switch to go with new Sirio I wondered if there is much to gain, or perhaps I am being greedy?
TIA
regards
Dave
I have a Land Cruiser 80 so quite a big car, it has a full length roof rack, that is it extends from the tailgate to around a foot past the front screen and is the full width of the car, so a substantial ground plane.
There is a metal wind deflector around four foot wide and 6 inches deep at the front and a new Sirio Super Carbon is bolted through that, then there is a short length of RG58 going to a bulkhead mount through the roof of the car, this then is run down to an antenna switch, the switch is used when the rack is not on and the Ariel is used on the roof so a simple changeover without going through the SWR tuning etc. I get a good SWR on the rack and seem to get a good distance, a quick test the day before yesterday showed an easy ten kilometre conversation, this was with the car facing the person I was conversing with, as the meat of my ground plane is behind the Ariel I consider this fine.
Given the rack is earthed through the Ariel mount and then through the coax to the bulkhead mount connector also earthed to the car body, is there anything to be gained by additional earthing i.e. braided earth strap from rack to car body, perhaps at the rear?
I am pretty savvy with vehicle mechanics/electrics and have used CB's for many years my installs have just been fit/test and use with no issues, so while fitting all new coax/connectors/Ariel switch to go with new Sirio I wondered if there is much to gain, or perhaps I am being greedy?
TIA
regards
Dave
