don't waste your time. on the t-600s and the t-800s, disassemble the factory block antenna studs and file the underside of the mounting tabs down to remove the paint down to the metal. this will allow for proper metal-to-metal contact and solves "the ground issue". re-assemble the block metal studs and select a pair of top-loaded antennas tall enough to take full advantage of the extra vertical height allowed by the lower mirror arms while still allowing for 13'6" clearance limits.
the base (bottom) of the loading coil is the most electromagnetically active portion of the antenna in terms of maximum transmitted and received signal strength. the higher in the air the base of the loading coil is and the further horizon it is able to "see", the further the antenna/s will talk and hear.
alternatively, the lower the loading coil the more transmitter rf will permeate the cab interior creating problems with stray rf coupling and the like, not to mention the limited amount of signal usable to the rear of the tractor trailer. any tractor rig that is able to support the use of antennas taller than 5 - 5.5 feet provides a distinct advantage over the average tractor where mirror mounts are 8 - 8.5 feet above the ground. in this sense the 600s and 800s are virtual "radio trucks" compared to the rest.
</p>Edited by: <A HREF=http://b2.ezboard.com/bworldwidecbradioclub.showUserPublicProfile?gid=freecell>freecell</A> at: 4/22/04 2:28 pm