Monday, 7 November 2016

Loop skywire details

Look closely to see the North East pole
of the loop.
This could be the last year I assembled the loop skywire. Things are changing and the new antennamast is planned for next year. So, I might try another antenna for the low bands. Anyone reading this blog for years won't be interesting to read about this antenna anymore I guess. I started to use this antenna in 2009 and this is the 7th year I assembled it for wintertime. The loop has always been a solid performer and if you have 20X20m of room I recommend to build one to use it for NVIS on the low bands as well for DX on almost any band.


This year I have nothing to improve so I decided to take a closer look at the materials in use. I always focused at the whole image which is very difficult to photograph as the loop is just too large. 3 of the 4 poles are standing on 70cm M30 studs and to prevent the poles from sliding into the ground there are M30 nuts in the center.







The fiberglass poles are supported by nylon guywires which are tightened to some 30cm "goat" pins or nearby trees. I use some home made tensioners to get the right tension on the wire.









The guywires and of course the antennawire are connected to a large M30 ring. The ring slides over the top and fits perfectly. Since the top is smaller because you can connect the mast parts to each other the ring doesn't slide any further. Normally another mastpart slides over this end.




The antennawire is connected with a tie wrap at the first pole to prevent the feedpoint from moving. At the other poles this wire is going through a clip so it can move freely. This is done to get a even tension between the poles even when it storms. The antennawire is tensioned when finishing the construction.


I noticed the glasfiber masts are wearing after 7 winters. I've seen this at glasfiber antennas like the A99 and Diamond X30/X50 as well. This is not a good sign. The only thing you can do to prevent this is to coat all the mast parts with special paint or protect it with tape. These military mastparts have protection but after 7 years most of it has been vanished.

One of the poles is supported by a wall of the glasshouse. Unfortenately the brackets are not that good anymore either. They already were heavily used when I got them and not getting any better.









This is below the tiles on my roof. Were I connect my wires. On the other end
there are 2 ladderlines 1 mtr each inside the wall and finally through it to my antennetuner. You might ask why 2 ladderlines. Well, one is the spare. You never know what I have to experiment. May be I will connect both to antennas in the future? It never happened yet. I had a small experiment with 1 wire as endfed in summer connected to one of these studs. It worked but I got a lot of RFI into the shack which is probabely normal with that kind of single wire antenna.

Well, I hope you enjoyed some of the pictures. If you read this blog for the first time you probabely are interested in the rest of it. In that case you can read (and view) the articles I wrote since 2009 about this antenna:

http://pe4bas.blogspot.nl/2009/11/80m-horizontale-loop-1.html
http://pe4bas.blogspot.nl/2009/11/80m-horizontale-loop-2.html
http://pe4bas.blogspot.nl/2012/11/nvis-loop-op-again.html
http://pe4bas.blogspot.nl/2012/01/testing-repaired-horizontal-loop.html
http://pe4bas.blogspot.nl/2014/11/loop-up-some-pictures.html
http://pe4bas.blogspot.nl/2015/11/horizontal-loop-preparations.html
http://pe4bas.blogspot.nl/2015/11/loop-construction.html

4 comments:

  1. Hoi Bas, ondanks dat ik je al jaren volg vond ik het toch interessant om te lezen hoe jij het gemaakt hebt met de 4 masten en het gebruikte materialen. Ook ik dacht dat de groenen defensiestokken het eeuwige leven hebben maar schrik toch hoe het na zoveel tijd eruit ziet. Mijn boom in de elevatierotor voor de sat-antennes is ook gemaakt van deze groene stokken. Toch maar even in de gaten houden hi.
    73 Hans, PE1BVQ

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    Replies
    1. Hallo Hans, het leek me wel leuk om het eens zo weer te geven. Die stokken hebben zeker niet het eeuwige leven. Glasfiber zo ie zo niet. Daarom heb ik mijn vertical in het verleden en nu ook weer volledig bedekt met tape. Al is het bij mijn vertical die ik nu gebruik ook ter bescherming van de koperfolie. 73, Bas

      Delete
  2. Wat ook wel wil helpen is ze goed in de lak spuiten. Wel goede uv bestendige lak uiteraard.

    ReplyDelete
    Replies
    1. Ja is een idee Peter, maar moet ook flexibele lak zijn dan he. Alles buigt best wel door onder spanning. 73, Bas

      Delete

Thanks for your comment. Bedankt voor je reactie. 73, Bas