I just got done installing my 3 foot firestick2 on the rocdoc spare tire mount. I hooked it up to the meter to tune it an I keep getting readings of 2.8 across channels 1,19,and 40. I'm guessing this means it is not grounded but I ran a 14gauge ground wire with ring terminals from the chassis in the cargo area under the hummer sill plate to the spare tire (on top of the mount and under the torx bolt nut just like it showed to in the thread by doc olds. What else could be causing this and how can I get these numbers down? Thanks for the help.

 

the ant length is critical and if u have an adjustment it should make a difference.
a heavy wide ground is better than plain wire.

a mag mount in center of roof is probably best short of drilling a hole and mounting it solid in the center.

anything under 2:1 is ok,,1:1,perfect

 

I just tuned a new antenna yesterday...

Any vertical surface within 20" of your antenna will promote SWR.
Antenna should have 2/3 of it's length above other parts of your vehicle.
Adjust the Firestick at the top, under the cap...1/4 inch at a time & check SWR.
Ground should go from basemount of antenna to nearby ground spot.

I got mine down to 1:1 SWR & 3 Watts of output, sounds nice & clear.