View Single Post
  #4   Report Post  
Old June 21st 04, 06:39 AM
Rick Frazier
 
Posts: n/a
Default

If I interpreted the manual correctly, it indicates one should insulate the
antenna base from a pole or tower that is nearing 1/4 wavelength. It didn't
seem to caution against conventional mounting if the tower or support pole was a
different length....

The manual seems to provide reasonable information regarding the use of radials
at 45 degree droop, recommending their use if possible. Ground mounting is
generally noted as being less desirable than roof or elevated mount with 45
degree radials...

I have a 5BTV and the antenna on the higher bands (10, 15, 20, 40) has
reasonable bandwidth, but on 75 meters the bandwidth is extremely narrow, do
much so it is nearly useless unless you have a single frequency you normally
use... Sitting on the ground, using two radials per band provides acceptable
performance on 10-40m, but on 80, it took 4 radials to get the swr down to
1.5:1, and even then, the bandwidth between the 2.0 swr points is only about 60
khz at best. You really need to pick your operating frequency for 80m. In a
few weeks I'm going to try to roof mount it to see if I can get a wider
bandwidth on 80m.

Good Luck!

--Rick AH7H


AA5QT wrote:

I have a 6BTV that I'm about to install. It will primarily be used for
80/40/30 meters. Some questions:

I could elevate it, if it would improve performance. The manual says not to
ground the radials or the antenna base, so I could mount the unit on an
insulated mast, and string the radials at a 45 degree angle....

Or I could place it near the ground, or try a metal mast, or....

Any experience/suggestions?

Gary K5QT