Thanks for sharing your story Steve. Scary stuff.
So glad you came out of this accident without a serious injury.
Looking forward to hearing you on 160 this winter with the new driven
element.
Tree N6TR
On Mon, Sep 2, 2024 at 7:55 AM VE6WZ_Steve <ve6wz@shaw.ca> wrote:
> Hello fellow DXers......
>
> VE6WZ will be QRT from the HF bands above 160m.
>
> On Tuesday Aug 27, I suffered a main lift cable failure on my crank up
> tower that destroyed all of my Yagi's and the US tower.
> At the time of the failure, I was beside the tower (doing work) in my man
> lift while the tower was going up.
> The tower was almost at full height (at 100') when the main lift cable
> broke.
> About 500 pounds of Yagis came crashing down almost instantly from 100'.
> I was in the manlift, and my reaction was to "go down" into the man basket
> when I heard the crash. This is what saved me. The man basket cage was
> somewhat damaged and bent.
> I am totally ok, with not a scratch, but the cage of the man basket
> protected me.
> There was debris, bolts, brackets, tubing, pieces of the booms flying
> everywhere, but somehow, the man lift was not knocked down. After the
> collapse, one of the 80m Yagi elements was laying on the man basket, but I
> was able to push it off, and lower the man lift to get out.
> The tower, my 80m-40m Yagis are completely destroyed. Unrepairable. The
> high band Optibeam is probably repairable.
> https://drive.google.com/file/d/1WPDpMbGaS1r8qgjWlj4AFyS8Gog5uSnY/view?usp=sharing
> <
> https://drive.google.com/file/d/1WPDpMbGaS1r8qgjWlj4AFyS8Gog5uSnY/view?usp=sharing
> >
>
> Why did this happen?
> It was my mistake.
> I am building a 4 element, 160m, 6 direction triangular parasitic array
> and needed to modify the shunt feed for the US tower crankup. The crankup
> is the driver for the parasitic elements.
> The existing shunt feed for the tower needed to me modified into a
> symmetrical skirt surrounding the tower to maintain balanced coupling to
> the parasitics.
> I clamped brackets to the outside of each section to support the
> shunt-wire standoffs.
> These clamps were working well for the last 3 months, but after a high
> wind, some of the shunt wires moved and caused the support arms to bend
> inward.
> This bending shifted one (or more) of the brackets to bend INWARD into the
> inner moving sections, then toward the main lift cable and basically sliced
> the main lift cable.
> The point is, this failure was not something that would have happened
> normally, but was only because of my poor engineering/ modifications. I
> guess that’s why they are called accidents?
>
> I have owned the US tower crankup for 26 years, (beginning at my city QTH)
> and have been fastidious about maintenance of the cables, sheaves and
> motorized raising fixture, and have had trouble free use of it.
> I will miss it.
> My homebrew 80m-40m 2 el Yagis have been in service for 22 years and I
> have had great enjoyment using them.
> On 40m I have worked DXCC Honour roll with 336 confirmed, and have 293
> DXCC confirmed on 80m.
> I really wanted to make it to 300 DXCC on 80m, but maybe that will
> encourage me to build an 80m vertical array?
>
> I have decided not to replace the tower. I want to simplify my remote
> station, and looking back over the last few years, I have been almost
> exclusively active on 160m anyway.
> It has been pretty rare to hear ve6wz above 40m, let alone on 80m for the
> last few years.
> I plan to remove (and sell for scrap) the 2,000 lb US tower, and replace
> it with another 90' irrigation tubing vertical to complete my 4 element
> triangular 160m TX array.
>
> Here is a some detail about the 160m array:
>
> The driver "was" the shunt fed tower, but that (next year) will be
> replaced with a 90' irrigation tubing vertical.
> There are 3 parasitic elements surrounding the driver (75' toploaded
> irrigation verts) spaced at 60'.
> At any time, 3 elements are active, one parasitic tuned as a director, the
> other as a reflector.
> The array is a variant of the classic K3LR, K9CT, VE3EJ 3 element inline
> array, but in my case, the 3 elements are spatially "offset".
> For example, the north parasitic tuned as a director pushes forward gain
> north, but the SW parasitic pushes the pattern NE.
> The really crazy thing, is that modelling shows the forward gain and F/B
> to be down only .4 dB from the inline design, PLUS, I get 6 directions!
> To my knowledge no one has ever built an array like this.
>
> Before the tower collapse, I actually had completed the array and was just
> finalizing the expanded radial system for the north element. (another
> 8,000' of copper wire)
> I had done some field testing with my signal source and RX testing in the
> field while TXing. The field test where identical to my model.
> The array shows 3.5-4dB forward gain (compared to a single vertical) and
> about 20 dB F/B.
> My plan was to make a YouTube video (and a .pdf paper) describing the
> array, modelling, installation and field testing, but that will now be
> delayed until next year.
>
> Since the tower failure, I have already modified the north parasitic, so
> it is now tuned and fed as a driver, and using the SW and SE parasitics as
> refelctors I at least have gain to EU and JA.
> So VE6WZ I will still be QRV on 160m this winter season.
> My 9 band RBN CW skimmer is offline until I reinstall a new antenna since
> that skimmer antenna was on the tower.
> Both of my 160m RBN skimmers are still running.
>
> That’s a long story, but I wanted to share this with the topband community
> since the VE6WZ remote station will be taking a slightly different
> direction.
>
> Steve, Ve6wz.
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