Fw: [TowerTalk] Force 12 C3S Experience
Thu, 5 Nov 1998 13:55:28 -0500
From: Natan Huffman <email@example.com>
To: Greg Clark <firstname.lastname@example.org>
Date: Thursday, November 05, 1998 1:53 PM
Subject: Re: [TowerTalk] Force 12 C3S Experience
>Sorry to here of your experience.
>I've included below a copy of my response to another customer who wrote me
>with a similar experience. Have copied the reflector too, as you did.
>this helps....write if you have problems with the second one.
>The elements are in
>bundles marked with the element number and either A or B. Once the center
>of each element is mounted on the boom, you are left with a center section
>that has A on one end, and B on the other. The intent being that the
>marked A goes on the side marked A, and the bundle marked B goes to the
>element end marked B. Each piece of tubing is marked as to placement. If
>the contents of the bundle are interspersed, assembly time is increased,
>however, you should be able to get everything right as the markings tell
>where to put each element.
>I think that sounds simple enough!
>If you try to integrate a bundle marked A with a element marked B, you will
>have the problem this gentleman encountered, NAMELY, THE HOLES WON'T LINE
>As far as standing the array on end, well that usually just won't work.
>elements are seeing ground capacity and being de-tuned.
>From: Greg Clark <email@example.com>
>To: firstname.lastname@example.org <email@example.com>
>Date: Thursday, November 05, 1998 11:30 AM
>Subject: [TowerTalk] Force 12 C3S Experience
>>Well, it's my turn to let you in on some of my Force 12 C3S experiences.
>>I purchased 2 C3S's almost 18 or 19 months ago. They've been in the
>>barn until time and money allowed me to do some work with them. The
>>idea was to have 2 of them in a stack configuration for my second radio.
>>Well, I still don't have alot of time or money, so my goal has been to
>>get one of the antennas on a side-mount dedicated to radio #2. I
>>started working on the antenna on a Sunday and have been doing part-time
>>work on it from that point. It has taken about 3 hours total to
>>- No major ones, but I was starting to worry. The first element
>>assembled needed to have six rivet holes re-drilled. This number
>>decreased for each element thereafter until I got to an element that
>>needed no drilling..yea.
>>- Tuning...what a pain in the rear..at least for 10m. I've seen similar
>>comments from others and I can tell you "I feel your pain".
>>My tuning setup consists of about 40ft of RG-213...not the 100ft as
>>defined in the manual. I then connect an Autek RF-1 antenna analyzer to
>>one end of the 213 and the other is feeding a new W2AU beam balun. To
>>tune the antenna off of the tower, I hoist the antenna between my 2
>>towers so that it is pointing straight up with the reflector about 6
>>feet off of the ground.
>>Out of the Box - Per the manual SWR points are as follows:
>>1.5 - 14.0
>>1.2 - 14.1
>>1.0 - 14.2
>>1.3 - 14.3
>>2.9 - 21.0
>>2.2 - 21.1
>>1.6 - 21.2
>>1.1 - 21.3
>>1.3 - 21.4
>>7.5 - 28.0
>>6.6 - 28.2
>>5.5 - 28.4
>>4.4 - 28.6
>>3.2 - 28.8
>>1.0 - 29.33 - Kinda high in the band huh?
>>Well, per the manual, I was able to lengthen the 15m element and ended
>>up with a curve that I was happy with. Here is it's final plot.
>>1.8 - 21.0
>>1.4 - 21.1
>>1.6 - 21.2
>>2.2 - 21.3
>>3.0 - 21.4
>>On 10m I was in a pinch. On one of the 10m elements, there were only 3
>>rivet holes to extend the element, on the other 10m element there were
>>4. Even when I extended the element tips to their maximum, the resonant
>>point on 10 was up at 28.600.
>>So, due to me running out of element tip to lengthen, I then went to the
>>next section of the element toward the boom to look for some extra
>>length. I did this on both 10m elements. This was not a quick and
>>simple process. I finally ended up with the following curve for 10m.
>>2.2 - 28.0
>>1.4 - 28.2
>>1.7 - 28.4
>>2.9 - 28.6
>>4.3 - 28.8
>>It ain't great but it's better that what I started with.
>>>From the time I hoisted the antenna up the first time to the last time
>>that I sat it back on the ground was 2 hours 50 minutes. The majority
>>of that time was jerking around with the 10m settings and then
>>re-engineering it in the field (drill rivets/drill new holes/pop
>>rivets...measure..etc). This was not fun. Thank goodness it's not a
>>big antenna but it was still a pain and to boot it was about 30 deg F
>>all the time.
>>I have another one of these to put up...probably next Summer, but at
>>least I will have my notes to get me through that assembly and tuning
>>I don't have the antenna on the tower yet. I hope to have it in place
>>for SS this weekend. I'll let you know how it performs, but I did want
>>those that have the C3S and have had problems on 10m to know that there
>>is a way to make it work. I, like other TT posters wonder why the
>>antenna was designed for such a high 10m resonant frequency of 28.800.
>>Why not ship it with about 4 more inches of length in the 10m elements
>>to save the majority of the users the above described procedure?
>>Hope this helps someone out there.
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