[TowerTalk] SteppIR installation

Martin Sole msole at loxinfo.co.th
Mon Jan 17 10:00:10 EST 2005

Thanks Joe, some good ideas.

On the thermal cycling we get temperature changes of about 10 degrees C all
year. Now, midwinter we see daytime tems about 27 Centigrade, nightime drops
a couple of degrees. Midsummer sees about 35 C. Do we need to worry about
thermal cycling? We do plan to assemble on Wednesday and put up on Thursday
so should be able to check anyway.

Martin - HS0ZED

-----Original Message-----
From: Joe Subich, K4IK [mailto:k4ik at subich.com] 
Sent: 17 January 2005 21:47
To: 'Martin Sole'
Subject: RE: [TowerTalk] SteppIR installation


> Tomorrow myself, HS0ZED, and John, W2YR, will go to the shack of our 
> good friend Eddy, HS0/EA4BKA, to assemble and install his new 3 el 
> SteppIR. We have allowed ourselves a couple of days to complete the 
> job staying overnight in Pattaya which should be fun. I would 
> appreciate any comments or suggestions from those that have already 
> been through the process regarding anything we need to consider before 
> starting.

1) Be careful in attaching the control wires to the terminal 
   strip.  They are not in the "logical" order so check and 
   double check. 

2) Allow the rubber boots that connect the fiberglass tubes 
   to the element center units to thermally cycle and retighten 
   them before putting the antenna into place. 

3) be careful (and double check) the center pin of the SO-239 
   socket on the driven element unit.  There are reports of 
   an occasional unit in which the center pin was pushed back 
   into the box.  

> We will install an EF140 at right angles, i.e. parallel to the boom of 
> the SteppIR. Is it okay to place this just a few feet away give the 
> orientation or do we need to be more careful?

Six feet should be fine.  The SteppIR's parasitic elements are insulated
from the boom so there will be no end-loading of the boom that might make it
resonant on or near 40.  My modeling shows that both the three and four
element SteppIR are nearly 
transparent to 40 meter dipoles.   


   ... Joe, K4IK 

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