[K3VOA] Home Station Building

[Ken Claerbout]

Hi Noy - thanks for the information.   I can take it up another 15 feet and may do so, to see what changes occur.

By the way, I was KE9A/DU3 from 1988 - 1991 when the embassy had housing on Clark Air Base.  I enjoyed the Philippines immensely.

Ken




Ken Claerbout
Broadcast Technologies Division/Engineering & Transmission Directorate
U.S. Agency for Global Media | Broadcasting Board of Governors
330 Independence Avenue SW | Washington DC 20237
kclaerbo at bbg.gov // Office: 202.920.2172 //http://usagm.gov
________________________________
From: Benigno Santi III <bsanti at usagm.gov>
Sent: Thursday, January 2, 2020 9:36:30 PM
To: Ken Claerbout <kclaerbo at usagm.gov>; k3voa <k3voa at mailman.qth.net>
Subject: Re: Home Station Building

Hello Ken,

VSWR/Freq response will shift shift very slightly in few KHz.  I remember pre-tuning wire loop antennas to waist level, and raising them to 20 feet above ground, will raise the frequency response, and beyond 20feet, no more shift in vswr/freq response. i tried it with 80m and 40m square loop. Congratulations.

73
Noy
DV1SCO


________________________________
From: k3voa-bounces at mailman.qth.net <k3voa-bounces at mailman.qth.net> on behalf of Ken Claerbout <kclaerbo at usagm.gov>
Sent: Friday, January 3, 2020 6:33 AM
To: k3voa <k3voa at mailman.qth.net>
Subject: [K3VOA] Home Station Building


Most of you have heard me talk about putting up a couple of towers at my house.  My old QTH had two 90' towers.  I'm basically doing the same here.  The first antenna is a M2 3 element 40 meter beam (40M3C).  The boom is 32'.  The elements are physically shortened by loading coils.  Those are the round tubes you see in each element.

My second tower is to 45', where it waits for the first set of guy lines.  I mounted the boom of the 40 meter beam about chest high on the side of that tower, and used that as a place to build out the rest of the beam.  Once completed I ran an SWR sweep.  As expected, because the antenna is so low to the ground, the curve came out below the 40 meter band, but it looked good otherwise!  New years day I took it up to 30', so I could see what the curve looked like.  As expected, it did shift upward in frequency. But I was a little surprised it moved up as much as it did.  The curve at 30' is about where I want it.  So the question is what will happen when it gets installed on the tower at 85'?  I've asked the manufacturer if they have any thoughts.

I've attached a picture of the antenna and the SWR plots.  The blue curve is with the antenna at ground level.  The green trace is at 30'.  Hopefully the attachments are passed by the email reflector.

Enjoy!

73
Ken K4ZW


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Ken Claerbout

Broadcast Technologies Division/Engineering & Transmission Directorate

U.S. Agency for Global Media | Broadcasting Board of Governors

330 Independence Avenue SW | Washington DC 20237

kclaerbo at bbg.gov // Office: 202.920.2172 //http://usagm.gov<http://usagm.gov/>