[TowerTalk] TH7 Tuning

[Barry Merrill]

TH-7 Serial Number 1 was sent to Dallas in Feb 1981, after I had ordered a
TH-6 
and the factory called to ask if I'd like the first one sold; the other two
TH-7s from their test range were kept by employees.
 
Judy not yet KA5PQD,
 (later, after she fibbed about joga class only to come home with her
   real Code Novice License)
and I assembled it across Valentine's Day weekend!

That antenna remained at 50 feet on an EZ-way tilt over tower until
2003 when I put up an OB16-3 and CAL-AV 2el 40 on a 72 foot crank up.


A few years ago, my good friend, Dr. Pat Sommier, W5WMU, who became an SK
this past April, picked it up in Dallas and put it up in LA, as I worked
it from both Dallas and Ireland, from LA, and more recently, I worked it
from US and EI after he had installed it at his ME QTH.
  
If you need spare parts!!

73

Barry, W5GN

-----Original Message-----
From: TowerTalk [mailto:towertalk-bounces at contesting.com] On Behalf Of Ted
Boerkamp
Sent: Sunday, September 24, 2017 3:18 PM
To: Towertalk Reflector (E-mail) (Towertalk Reflector (E-mail))
<towertalk at contesting.com>
Subject: [TowerTalk] TH7 Tuning

Hello everyone...I currently have my TH7 sitting on sawhorses after
rebuilding all the traps and replacing

lot of hardware with new stainless stuff. I know that to properly check the
beam for tuning I have to either

get it off the ground horizontal (up 20 or 30 ft) or stand it up on the
reflector end aimed at the sky

before attaching the analyzer to check the curves.

On the sawhorses, the beam is currently showing 4:1 swr on 20, 1.9 on 15 and
1.6 on 10.

Is this what I should be seeing in this case?? I am hoping to try again
standing it up this afternoon.

The reason for taking the beam down was a problem with 20m showing a flat
2:1 across the band intermittently.

Now it appears to show a curve but resonance is probably below 14mhz and not
in the middle of the band.

Also wondering if the wire harness that holds up both ends of the boom could
be changing things as it is drooped across the

middle elements and I assume shorting things out and changing the resonance.

Any info or suggestions are most welcome. 

Thanks

 

Ted VE3SS

 

p.s. using a rig expert AA-54 analyzer

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