Wednesday, November 21, 2012

Joined the 43ft Vertical Club

Well, I have officially joined the 43ft vertical club.  The ubiquitous 43ft these days seems to be turning into the vertical antenna equipment of the G5RV.

Having a couple of days off, I finally got a chance to do the full install of this antenna, just in time for winter.

First I had to run a new coax line of RG-213 out to the back corner of the yard from the shack.  I took the 'shallow trench' made with a spade approach which I have used in the past.  I also am starting to like RG-213 more than LMR-400.  The specs are nearly the same, but the RG-213 has a solid PE (looks like hard plastic) dielectric inside it, where the LMR-400 has foam.  I think the RG-213 will actually hold up better long term outdoors and buried.   I have concerns about LMR-400's foam getting full of water seeping in the coax over long term.  But, that being said I do have 2 runs of LMR400 already in the ground that have been there for about 4 years now with no problems.   But if I ever have to replace them, I think will go with RG-213 next time for those as well.

After the coax was run, I decided I needed to upgrade my single point ground panel.  I had used a pretty nice all aluminum NEMA box I got from a surplus site when we first moved into this house(see it in this previous blog post), it was kinda small inside being only 8x8 inches and it was going to be very full by the time I put a 3rd coax line and polyphaser through it.    I had originally purchased some of the nice watertight cable feedthrough couplers from DX Engineering to use with my box, so I went to their website to look at ordering some more for this new cable run, but then I came across a new offering.  They now offer their own nice weatherproof box, along with some of those coax feed through couplers, an aluminum panel for inside, and even a little copper bar to use in mounting copper strap like I have to the grounding panel.  Pretty much everything you need to setup a single point ground box.  AND, it was 13x14 so quite a bit bigger than the one I originally used.  I decided to spend just a little more money and get the whole kit.  Really, at $49.95 this is a very good price.  

Most of the time, just finding a NEMA box will run you that much by itself, and this has pretty much all you need.  I highly recommend it if your wanting to setup a single point ground panel yourself.

So I ended up replacing my entire single point ground box, and remounted and reconnected everything including a new HF PolyPhaser and coax for the new antenna.

Here is what it looks like now:

So now, that I have to coax run and connected, it was time to install the vertical antenna.  I did not purchase a pre-made antenna such as the S9, or ZeroFive, I decided to build my own.  

I had visited a number of companies at Dayton this past year who were selling telescoping vertical sections of fiberglass.  After checking some out, I decided that the ones I had seen that were being sold by the SpiderBeam people were the best.  They were much heavy duty than the ones that were being sold by people like S9.  In fact the ones that SpiderBeam sells can hold up a small beam or easily the center of the lightweight dipole.  The fishing poles used by S9 are very thin and flexible at the top and will not hold any weight at all.    But the Spiderbeam poles are still light enough (only 7 lbs)  for one person to put up and take down easily.   I purchased the 12m long pole, which is available here for $119 US: 

They have other lengths available as well, including 18 and 26 meter long versions.  

The other part of this antenna consists of a unun at the base of the antenna to convert from the coax to the vertical, and radials.  I used a 4:1 unun made by Balun Designs that they recommend for the S9 verticals,  

For the actual antenna conductor, I used electrical tape to affix a wire to the entire length of the fiberglass pole, taping it at the top, and then taping it at each fibreglass section.  I did not want it to be too tight since the pole will bend in the wind, and the wire needs a bit of play.  I used a single wire of "silky" 14 AWG wire from which is very flexible wire and perfect for this purpose.  

For the installation, I decided the most stealth location I have is to attach it to my kids 'tree house' which is right under my best tree, and the same tree I currently have the center point of my 80m OCF diple hung in.   I attached the fiberglass pole to one of the legs of the tree house and extended the poles up into the branches of the tree.

It is attached with bungee cords right now to the tree house legs but I am going to come up with a more permanent solution using pipe clamps or something soon.   I might make a little wood platform attached to the tree house leg to sit it on as well, and that would allow me to raise the bottom up off the ground 3-4 feet or so to get it a little higher in the air.

I also built a little loop of copper plumbers tape and some stainless bolts and nuts to serve as my radial base and put it around the leg of the tree house.  I then laid out 10 radials(more coming soon) of 40 ft or less in all directions from the tree house and connected everything to UNUN and it was done.

Hopefully, this will be stealth enough not to get any neighbors upset with me.  It does blend in pretty well with the tree after you get far enough away.  

Here is a picture from a distance and you can kind of see how it starts to disappear.  And in the spring when there are leaves on the tree, there is no way you would be able to see it much at all.

So far doing some tests sometimes the vertical is louder than my 80m OCF inverted V, and sometimes it is a little lower on the signal receive.  I am sure it is going to depend on the station I am trying to work, I imagine some will work better on the vertical and some on the horizontal dipole.  But at least now, I will have the two antennas to switch between and see which works better.  Before I only had a dipole and it either worked or not.  

Here is the first pass of the antenna analyzer on the new vertical.  You can see its really pretty decent for 40m-10m at 4:1 or less which is well withing the range of my LDG Tuner and the loss will not be very high, but its not that good on 80m where the SWR is up about 7:1 and the losses will start to add up..   I will probably use it mostly for 40 and up, and I might consider building a loading coil for use on 80m.  But for now I will just see how it works within its known limitations.