Towertalk
[Top] [All Lists]

[TowerTalk] Yet another Query

To: <towertalk@contesting.com>
Subject: [TowerTalk] Yet another Query
From: K7LXC@aol.com (K7LXC)
Date: Sun, 17 May 1998 19:13:00 EDT
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

--
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

<Prev in Thread] Current Thread [Next in Thread>