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[TowerTalk] TH7 versus KT34XA

To: <>
Subject: [TowerTalk] TH7 versus KT34XA
From: (Bob Wruble)
Date: Thu, 26 Jun 1997 09:19:02 -0700
Have 3 kt34'xa in a stack.....i went with kt34xa's becuz if the 
success of certain well known contesters who used a 
single kt34xa at 70' to kick butt for years.......Dan Honda
w7wa.  I also like the broadband characteristics of the double
driven element design. 

kt34'xas are a bitch to build (at least very time consuming)
and if u make an error early on in construction you get to
rebuild them !!  but if u take ur time and follow the instructions
to the letter and remeasure each element CAREFULLY before 
putting the antenna in the air it will wk as advertised.

My three are at 92,132 and 172' a bit high some mite argue?
Actual performance for me is still a bit of a question mark since
have had only 20m prop to run checks on.  

I have an old Telrex TB-6 on another 105" foot twr as a reference
........sometimes the stack  is no better than the single tb-6....
sometimes the stack is btr but  not by as much as i wud like (6-8db) 
considering the investment  in aluminum. and effort in putting them up!    

I am hoping they will do btr on 10-15.    Had a incident in the AA
test this past wkend on 15 where a few JA's were leaking thru 
on the stack but i cud not hear most of them on the tri-bander!!
will see......

yes the swr is higher on 15m as they say it will....but in general the
swr curves on mine follow the curves in the book.

in summary you can not take enuf care in assembling these puppies.
when i first got my three i hurried into construction for a solid week with
a helper only to find out when i went to put the 1/2 elements on the 
booms that idiots had shipped me kt34's by mistake (not xa's) so i had 
to restart from scratch....needles to say i was pissed.

best solution to putting a kt34 together is to find someone that has done
it b4 if u can it will make a hell of a difference.......

> From: David L. Thompson <>
> To:
> Subject: [TowerTalk] TH7 versus KT34XA
To: <>
> Date: Thursday, June 26, 1997 7:45 AM
> Bill, W4AN is right..the KT34XA is a pain in the butt. But when it works its
> great.  Mine was beat up by Opal in Oct 1995.  The reflector has flipped
> over and is now upside down.  15 meters has high SWR.  20 meters requires
> the tuner and it keeps changing tuning.  I have replaced caps twice since
> 1981 when I got it...and I have a crank up so I can bring it down to roof
> level to work on it.  Altho cranking it down is a chore.
> I would suspect the problem with the TH7 would be the traps.
> Now someone at Hy-Gain passed the word that the TH11 has improved
> performance on 10 and 20 over the TH7.  Is this selling hype or truth?
> I run across a few who swear by the Sommer XP807.  KM1E wrote a nice article
> in the Dx magazine about selecting one antenna for 20 to 10 including the
> WARC bands.  I ran into him comparing the Sommer to the nice 4el that KA1PE
> uses on 17.  Compared nicely on short skip and FK8CP said they were the same
> at his QTH except KM1E faded a bit more.
> I think any of the above and perhaps the big Fritzels are all very close.  I
> would say don't spend too much time comparing...get one and get on the air.
> An advocate of "GAD"...Go and do it!
> Dave K4JRB 
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