In a message dated 98-05-16 09:34:12 EDT, n0av@netins.net writes:
> This would give me a 40/70 stack of TH7's which is supposed to be pretty
> good. I am wondering what the difference is between the TH6 and the TH7,
> can't find enough info about either one to satisfy me. i.e. how many
> elements for each band on each antenna.
The TH6DXX was designed in the 60's and immediately became the tribander
to beat. It works good! About 15 years ago, a second driven element was added
to enlarge the 2:1 bandwidth. Other than that, the antennas are just about
identical.
You'll need a tuner at times when the resonance is at the wrong part of
the band.
> I could save myself a ton of bucks if I get a pair of Th6's is the only
> reason I ask.
True but all TH6's are getting long in the tooth and are at least 10-15
years old. If you find some in good shape - go for it. Investing in "mature"
antennas may or may not be a good course.
> BTW top antennas would likely use Yaesu G800 and bottom antenna would
> likely use sometype of swinging gate system.
The approximate Effective Moment for a TH7 and 402CD is almost 2700
foot/pounds. The G800 is rated at 1,299 ft/lbs. Back to the drawing board.
Even a G1000 only has 2020 ft/lbs of capacity. You need a big rotator,
OB.
BTW for that load you'll need a mast with a yield strength of 50k psi and
0.125 inch wall @ 70 MPH.
> Has anyone ever stacked TH6's or TH7's at 40/70? if so how did they
perform?
Many have and they work great.
Cheers, Steve K7LXC
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