Folks
I replied to Natan privately from work today, but I wanted to share some
info with the group.
The elements were put together correctly. A to A, B to B...pretty
simple. I'm also of the mindset that if it doesn't work in a certain
configuration...maybe I had it backwards. I didn't.
I think some thought that I had to drill new holes at every section
junction. Not true.
What I ended up with was out of 3 rivet holes....2 would line up fine
but the 3rd was off enough that I could not get a rivet in the hole.
The result was I had to re-drill or drill out the 3rd hole to be able to
get a rivet in.
For the whole antenna, I had to do this 16 times.
As for ground effect and tuning. I don't agree with that
interpretation.
I have tuned all of my mono-banders via this method with great success.
I also don't believe that there was much effect proven by the 20m SWR
was just about on the money per the manual. The 15m curve was pretty
close as well. By lengthening the 15m element, the SWR moved just as
advertised in the manual. If ground effect were to have come into play,
I don't believe that I would have been able to get the 15 and 20m
results from the manual. I was just not a happy camper for the 10m
plots. I got it to work, but it was not a plug and play operation.
I also told Natan I was not upset at Force 12....I'm sure I'll buy more
of their hardware, I just wanted to let some of the others that had
issues know that they were not alone.
73/Greg
K9IG
Natan Huffman wrote:
>
> -----Original Message-----
> From: Natan Huffman <force12e@lightlink.com>
> To: Greg Clark <g.w.clark@cummins.com>
To: <towertalk@contesting.com>
> Date: Thursday, November 05, 1998 1:53 PM
> Subject: Re: [TowerTalk] Force 12 C3S Experience
>
> >Greg,
> >
> >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.
> Hope
> >this helps....write if you have problems with the second one.
> >
> >Natan W6XR/2
> >
> >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
> bundle
> >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
> you
> >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
> >UP.
> >
> >As far as standing the array on end, well that usually just won't work.
> The
> >elements are seeing ground capacity and being de-tuned.
> >
> >-----Original Message-----
> >From: Greg Clark <g.w.clark@cummins.com>
> >To: towertalk@contesting.com <towertalk@contesting.com>
To: <towertalk@contesting.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
> >>assemble.
> >>
> >>Problems
> >>
> >>- 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:
> >>
> >>20m (final)
> >>
> >>1.5 - 14.0
> >>1.2 - 14.1
> >>1.0 - 14.2
> >>1.3 - 14.3
> >>
> >>15m
> >>
> >>2.9 - 21.0
> >>2.2 - 21.1
> >>1.6 - 21.2
> >>1.1 - 21.3
> >>1.3 - 21.4
> >>
> >>10m
> >>
> >>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.
> >>
> >>15m final
> >>
> >>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.
> >>
> >>10m final
> >>
> >>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
> >>procedure.
> >>
> >>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.
> >>
> >>73/Greg
> >>K9IG
> >>
> >>--
> >>FAQ on WWW: http://www.contesting.com/towertalkfaq.html
> >>Submissions: towertalk@contesting.com
> >>Administrative requests: towertalk-REQUEST@contesting.com
> >>Problems: owner-towertalk@contesting.com
> >>Search: http://www.contesting.com/km9p/search.htm
> >>
> >>
> >
>
> --
> FAQ on WWW: http://www.contesting.com/towertalkfaq.html
> Submissions: towertalk@contesting.com
> Administrative requests: towertalk-REQUEST@contesting.com
> Problems: owner-towertalk@contesting.com
> Search: http://www.contesting.com/km9p/search.htm
--
FAQ on WWW: http://www.contesting.com/towertalkfaq.html
Submissions: towertalk@contesting.com
Administrative requests: towertalk-REQUEST@contesting.com
Problems: owner-towertalk@contesting.com
Search: http://www.contesting.com/km9p/search.htm
|