Topband: Tower failure at VE6WZ

[Mike Fatchett W0MU]

Steve,

Wow!  That is awful but you are one lucky son of a gun!  Glad you are 
still with us!

W0MU Mike

On 9/2/2024 8:55 AM, VE6WZ_Steve 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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