Firstly I must warn you this is a slightly odd topic, but I was hoping that somebody on the reflector may be able to help!
Yesterday (15/02/2013) I activated G/WB-003 on 144 FM using my HH, mag mount (for support) and my super slim jim. The activation went very well generating about 20 odd QSOs. I simply mounted the mag mount on top and used the slim jim as you dont need a ground plane. However being the slight eccentric that I am, I thought instead of the mag mount could I build a bracket for the support job!
The plan at the moment is to cut some sheets of aluminium approx 25 inches by 1.5 inches wide. Yesterday I had my tape measure with me and the top of the trig measures 15 inches by 15 inches.
I plan to mount them in a cross and bend the excess 5 inches down. Holes will be 2 small holes will be drilled for nuts and bolts to go in. In addition a larger hole will be drilled to mount a chassis RF socket (Yet to be decided but most likely N) I can then run Coax to this and connect a rig. Clearly though I may put a step in the bends to elevate the connector above the trig.
So I have the rough dimensions on top, what I am missing is the angle to which to bend the metal. Has anyone got a clue what the slope is on the standard UK trig points? I am not expecting anything, it may even come to being as sad as to take a protractor to my nearest one and work it out!
I just think that on summits where there is easy access to a trig setting this up would be a doddle with the slim jim or a mobile antenna with a set of radials. And would be a lot lighter than a mag mount that odes not work on trigs as the metal is brass!
Trig points are at least 1 metre high so act as quite a good platform to mount things on, so any ideas people?
When I was making my “Trig Jig” I took a spirit level up Walton Hill and determined that the slope was about 1 in 7, or an angle of just over 8 degrees to the vertical. This seems to have worked for all the “Hotine” type trigs I’ve encountered
I don’t know the dimensions of the square trig points but I can give you a big of info regarding trig points across the country…
The majority of Trig pillars were painted to provide protection from the elements. The colour white was generally chosen to improve the visibility however this is not as important as it might seem as long range trig observations were often made at night to lamps.
However, as to why some are painted and others not, this was simply down to the request of the original landowner:
Some landowners stipulated that some pillars must be constructed of unpainted local stone and not concrete.
Some landowners (farmers) stipulated that the pillars not be painted at all as they were concerned that livestock might ingest the paint.
Other landowners stipulated that pillars emplaced on their land be painted to actually blend-in with the landscape.
I have seen several kinds and many are in a very poor state. Apparently they are not maintained any longer and the freshly painted white ones are usually just landowner or bored individual with a pot of paint and a brush.
No Andy, look at the photos. Some are straight blocks, not tapered. And a fair number are like cemented cairns. Then, as you say, a number are in a bad way due to lack of maintenance - as you must have seen in GM/SS!
Sorry I should have said the concrete Hotine Pyramids and concrete Vanessa Cylinders will all be the same size. The others made from local stone etc. will be of the same overall size. The height of the brass insert where the theodolite was attached should also be the same across all points.
Should we really be using trig points as an antenna mount?
Certainly on popular summits I’d say this is a big No No.
The trig point is often the focus of others day out and very often somewhere where they wish to take a photo of their day’s conquest. For that reason I always activate some distance away and have never used the trig point as an antenna mount.
I expect there are many summits where there are not a great number of other people around and then activating in this way would not be a problem.
I haven’t found any of those yet!
I suppose we need to make that decision on a case by case basis.
I expect there are many summits where there are not a great number of other
people around and then activating in this way would not be a problem.
I haven’t found any of those yet!
A trip to Alex Salmond’s Peoples Republic of Alba and the insertion of an M into your callsign will allow you to experience more deserted trig pointed summits that you can imagine.