My FCC approved antenna pattern range is the overrun area of the local
airport. It is largely comprised of short weeds, rocks, and the occasional
dirt patch {;-)

If it wasn't freakin' winter, I'd put the 16' wooden mast with the up-n-down
mechanism for nulling out ground effects at VHF and see what the pattern of
a "real" SJ is. I think I'll wait for spring/summer for something that
really isn't time critical.

I hate to admit it, but the HP 608 is still the best thing I've found for
accurate attenuator calibration on the range. The Systron-Donner spectrum
analyzer with phase lock down to a few Hz. is the other end of the range; we
have large sheets of black conductive foam to keep the reflections from the
equipment to a minimum and use battery/inverter power to keep power line
interference down.

As for the choke balun referred to in another post, of course we use
decoupling toroids (3 of them are generally sufficient) where the coax
passes by the bottom of the antenna. Choke balun, decoupling ferrites, call
it what you will.

Jim



"Richard Clark" wrote in message
...
On Mon, 22 Jan 2007 14:47:21 -0800, "RST Engineering"
wrote:

Yet most folks experimental results seem to show a radiation pattern
squirted a lot towards the horizon and very little up and down.

Hi Jim,

Most folks, and many more sophisticated folks lack the skill to really
confirm this. It takes 10% tools and 90% common sense.