I have seen several posts in the last few weeks concerning stack
performance and checking to see if they really are "in phase". Simply
connecting the balun incorrectly certainly can produce tragic performance.
With this in mind, I suggest the following test: Turn the antennas to the
exact same direction and check the SWR...Rotate one of the antennas while
keying the transmitter and observing the SWR... stop the rotation when the
antennas are in exact opposite directions.
It has been my observation with many stack over the past 30 years that SWR
will be at minimum when the antennas are in the exact same direction and at
maximum when pointed in opposite directions. This may not be high tech but
it is a good tool to check a stack....
Remember... even a stack that aint great usually will beat a single
antenna! ( Been there done that)
73
Bud K4ISV
--
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
|