Contesting Archives - Page 5 of 5

RSGB 144MHz UKAC 5th April 2016

After hoping to enter the previous two sessions of the RSGB 144MHz UK Activity Contest series but for various reasons failing to get on the air this time I finally succeeded. It’s 18 years since my last VHF contest. This time I could try out my newly finished and as yet untested on air 9 element DK7ZB yagi and lightweight portable mast.

I checked the past year’s results to see if my old (from back in early 1980s) site was being used in the UKAC series. As it didn’t seem to be I chose to try there for this contest.

The original plan was Paul G1YFC would also come up for the contest (we won our last contest in 1998) but he couldn’t make it so I slogged up the hill with all the gear on my own to the trig point on Graig Syfyrddin which is at a height of 423m which a clear take off though has the 400m higher black Mountains West of it:

Literally every radio item I would be using for this contest was new to me since the last contests I did. It was a pretty calm evening so setting up was fairly straightforward and I soon had the mast and tent up:

Once I had the Yaesu FT-817 connected up and the tablet fired up I worked a few stations before the contest getting good reports from my QRP station which was good to hear. I did learn it’s much wiser to operate from a hill you can pronounce the name of though. One quick check outside before the contest starts revealed a nice sunset:

Once the contest started activity was pretty good. For the first hour or so I was exceeding 1 QSO per minute and getting great reports. Things did slow down a bit and QSOs came in little bursts of activity. I made use of the 2nd VFO for some search and pounce but was mostly running. Logging was done on my Surface Pro 3 using Minos by G0GJV. What I should have done I think was also try the ON4KST chat that everyone uses. It actually never occurred to me on the night. This was a great shame as I missed a couple of leading big gun stations somehow that would have given me some valuable new multiplier squares. Anyway I got 120 QSO in total which seemed respectable.
Here is my QSO map:

Packing up as quickly as I could by headtorch I headed down the hill almost running at some points. Even rushing it was midnight when I reached the car and 1am by the time I got to bed.

My claimed score (before adjudication) put me in 3rd place in my section. 4 multipliers (2 UK new squares) would have put me top! Missing those big station multipliers was very costly indeed!

Overall I am very pleased with the first go out this century. It was meant really as a practice run for the forthcoming 144MHz Backpacking series of contests and also the PW QRP Contest which I have always been a big fan of. The equipment all seemed to work well apart from one small temporary issue with the keyboard on the Surface Pro 3 failing to respond which was very inconvenient. I did get it going but without know how or why it stopped working.

Full result list (PDF)

Last updated 4th March, 2017

Ultralight and ultra strong antenna mast guying ring

When I made my lightweight aluminium portable contest mast I designed up a very lightweight guy ring to use that was both strong and light. I designed it for my friend to injection mould in a fibreglass reinforced plastic that is really strong. The material is so strong I could not damage a 1.5mm thick long credit card size sample by hand even across the edge of a table. All I did was hurt my hands.

So with one eye on weight and one on strength this is the design I came up with. The design criteria was that these rings would hold up a mast carrying a decent sized 144MHz long yagi with at least a 5m boom on an exposed mountain summit in winds at least as strong as the tent will take but also be nice and light and small. They are very similar to many others you will see (there’s only so many ways a guy ring can be designed), but this is only 61.5mm outer diameter and 14.2 grams in weight:

I went for the simple 4 holes rather than extra holes for 3 point guying that some rings offer as it’s easy enough to just use 3 of the holes. Rope holes are 5.8mm which is plenty big enough for 550lb paracord or other ropes you would use with a lighter weight mast system. The centre hole is 20.5mm sized to fit the top section of my mast. For the lower thicker section it’s easy to open the centre hole with a step drill, in my case 26mm. 30mm is about as big as I would open it too though to retain full strength.

When the rings arrived in the post the first job was to test it for strength. I figured I would make a good test load. Just needed something to hang off and give it some welly. I am a good 170lbs, probably more with boots and big coat on. The rucksack is full of 2 litre bottles of water, probably a good 30lbs more easy. So about 200lbs bouncing weight on the guy ring. This is on a very short length of paracord. A longer length will absorb more shock like a climbing rope does:

Once I was happy with them fitted to the mast and the guy ropes tied on:

And in action:

These rings will also be very useful for SOTA activations where the very ultralight commercially available rings may be a little brittle without adding a noticeable weight penalty. Used for a fishing pole mast the mast will break long before these rings will!

I mentioned that these could be ideal for other radio hams doing SOTA activations and other portable operations wanting a very strong but lightweight guy ring he has made these available (pretty much any quantity) on his website:
https://dura-id.store/product/lightweight-mast-guy-ring

Last updated 10th December, 2019

Guying down a lightweight portable antenna mast

Having just finished making a lightweight aluminium portable antenna mast for backpacking VHF contesting I wasn’t really happy with the initial way we were tying down the guy ropes.

Typically I have tied off guys that don’t have tensioners with several half hitches. These are quick and easy but they are hard to tie tensioned properly and I have lost two 19 element MET yagis, a Yaesu rotator and an aluminium scaffold pole when one guy worked loose on a windy day. I didn’t want to use tensioners on this setup as they can work loose and we are going to be operating from a tent and won’t see any loose guys until too late most likely. Also I’m using for this mast lightweight paracord which is meant to be good to 550lbs breaking strain, but I am wrapping that around fairly sharp edged aluminium angle guy stakes which might create a weak point on the paracord. The mast is not massive and I have 2 sets of main load bearing guys but I want this to stay up on exposed windy Welsh mountain tops.

So I thought a round bar would be a better shape to tie the guys to and a clove hitch would be a good start knot as it can be tightened up. For the round bar I thought I would use some of my old climbing karabiners. And to attach those to the guy pegs I would use some small sized climbing rope about 6 or 7mm and use a clove hitch to quickly attach those to the pegs.

Here are the karabiners and rope loops. The rope loops were made from about 1m of rope each and a double fisherman knot used to make the loop:

Once the karabiner was fitted to the guy peg it was very quick and easy to make a clove hitch and slip it on, tension, then lock off with a couple of half hitches:

This adds an extra 381grams to carry but I think it will be worth it in the long run. I could probably cut that down with newer smaller and more lightweight climbing karabiners (I’m not going to risk the cheapie ebay style mini ones) and probably a smaller rope would be OK to use:

This is one way of many options, I’d love to hear your methods and tip and tricks!
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Last updated 4th March, 2017