Complex subject...and one which is fraught with .... opinion.
there's also data, but why let that get in the way?
Here's my observation:
1) Tennadyne T8 was a great antenna. Outperformed any trapped 3 el
tribander I came up against, including one on a test stand at my site.
It's essentially a 2 element beam, but high efficiency.
The LPDA offers instand frequency change, and is wideband susceptible
to input signals from out=of=ham=band broadcast. the CC 2010 wasn't the
equal of the tennadyne.
2) The 3 el steppIR outperformed it. period. but at significantly higher
cost. I could stack a pair of t8's for the cost of a steppIR. However,
when
the falling oak took out the tower and smashed the t8, I bought a steppIR to
play with. NICE antenna. Hard to beat with anything but a monobander on an
equivalent boom. The SteppIR is a tuned antenna, so you won't have wideband
bcdst dumped into the rx front end.
3) I looked at stacking a pair of 18' boom tennadynes, with the lower one
tilted up by 30 degrees and the upper one tilted down by 30 degrees. The
result would have been a .5 lambda spacing (approximately) on all bands.
Attempts to model this ran aground...and before I could make it fly,
my 100' tower was done in by the aforementioned falling oak.
4) trapped tribanders aren't the equal of either antenna.
5) Tribanders which are essentially three monobanders on a common boom
stand a chance of beating the SteppIR over a narrow range. But not by
much. Wherever they're off their sweet spot, the SteppIR will win. And
the log periodic may, as well.
6) I liked the logs for their simplicity. But the steppIR went together
a heck of a lot faster, and went up easier.
n2ea
jimjarvis@ieee.org
_______________________________________________
See: http://www.mscomputer.com for "Self Supporting Towers", "Wireless Weather
Stations", and lot's more. Call Toll Free, 1-800-333-9041 with any questions
and ask for Sherman, W2FLA.
_______________________________________________
TowerTalk mailing list
TowerTalk@contesting.com
http://lists.contesting.com/mailman/listinfo/towertalk
|