Many thanks to W0AW and N7ML who suggested that I double-check
the phasing of my stacked yagis. I was working on the ring
rotator, and re-checked the lower feedpoint. The antennas are
direct-fed with coax, and the only "balun" is the 6 type 43 beads
I slipped on the RG-213 just before the feedpoint.
Sure enough, the phasing was backwards. I corrected it, and now
the stack is almost always superior to any single antenna, just
based on one day of testing. Kind of an embarrassing mistake,
but I'm real glad to have it right. BIG difference. :-) Many
thanks to the more experienced on here for setting me straight.
In other news, I got the ring rotator to follow the preset control
so I can now actually steer it with some confidence. Unfortunately
I still can't truly rely on the meter to tell me where it's pointed,
as the calibration doesn't seem to hold steady, despite many full
calibration sweeps as suggested by Carl. The preset control seems
to be fairly repeatable, and I'll now rely more on that than the meter.
Hopefully the new SW update (still in vapor form) will correct the
meter calibration problems.
A steerable stack that works, at last. Really looking forward to
doing some more on-air TESTing now. Thanks again for the help folks.
-Kirk K4RO
--
FAQ on WWW: http://www.contesting.com/towertalkfaq.html
Submissions: towertalk@contesting.com
Administrative requests: towertalk-REQUEST@contesting.com
Problems: owner-towertalk@contesting.com
Search: http://www.contesting.com/km9p/search.htm
|