[Antennas] elevated vertical

[Mel Vance]

An idea for easier tuning on an elevated vertical....based on experience gained from CB 
antennas and another local hams antenna mounted on his garage roof (a gap, I think). Take 
it for what it is worth...you get what you pay for...and this is free.....

When installing CB antennas, I have found that making all adjustments at about 20 feet (on 
the roof of the house for easy access), no further adjustments are needed when installed at 
the final location at 60 feet. Antennas adjusted this way include a 1/2 wave ground plane, 
a5/8 wave ground plane, and a 1/2 wave vertical dipole. This method will work well for the 
higher HF bands as 20 feet is fairly high in terms of wavelength.

On another note, for those looking for a good 12 or 10mtr antenna...

I have had great success using many CB antennas on 12-10. Have not found any 1/2 wave 
or 5/8 wave ground plane antennas that would not work well. I have not had very good luck 
with the Antron A-99 or Solortron style antennas with the tuning rings. I have gotten them to 
work OK by cutting the rings off and using a tuner.

On another hams multi-band vertical, we temp mounted on the rear of my truck bed. All coil 
tap adjustments were made there. Antenna was then mounted on the roof and 4 radials for 
each band added. Antenna was able to be tuned on all bands with the internal automatic 
antenna tuner. Due to band width limits of the antenna, only a small part of the lower bands 
could be matched. Can give a report on TX signals as the nam in this case was a Tech, and 
RX reports are suspect as there was no other antenna to compare with. In my brief look in 
the shack, seemed to work as well as could be expected.

An idea on tuning for use on a push up mast, you may try the following method.......

Cut your radials about 7% long. Temp install on your roof and adjust the antenna only on 
each band. Temp raise to your final hight. Re-check your match and note the change from 
the lower height. Drop down to the roof and re-adjust, taking into account the change. Now, 
it should be on where you want when put up at the final height. After installing in that 
location, trim the radials for max sig strength. You may be able to use a field strength meter 
to find the peak point on the radial wire and cut at that point for max sig strength. The higher 
bands could be trimmed to final length while on the roof, but lower bands will have to be 
done while in the final location. Could still be fun to reach them......

I have not tried this method on the lower bands, but is similar to what I do on 12-10 mtrs 
with great success.

Mel
N7OKL