I am thinking of buying some aluminum to try and build something similar but with max. mast height of 10 m.
1. Is this a difficult project, assuming I can find the right aluminum?
No. It requires some assessment of the potential wind loading and required strength of the aluminum
tubing, and some adjustments to make it more practical, but what can be difficult about nesting
tubing sections and putting a clamp on one end of each piece?
2. Instead of building a telescoping mast, could I use 2m sections of identical diameter aluminum and join them? Maybe cut a short piece of overlapping aluminum tube and join sections with that?
Yes. I have some of the military mast sections that are built this way, and I find them to be very
convenient. Strength is maintained all the way to the top of the mast, which may be an advantage
for heavy loads. I think my sections are about 1.75" ( 4cm ) in diameter and we have put up a
4-element 15m yagi at 28' ( 8.5m ) on it with one set of guys. These use an insert that slips
inside the main tubing at each end.
Part of the decision may be whether you are buying the aluminum tubing in Europe or the US.
There are different standards, with the Metric tubing typically having thicker ( 2mm ) walls.
The US tubing tends to telescope better than the metric sizes, however.
I also found some old aluminum tent poles that stack nicely. They are about 2cm diameter.
I only have enough to go up 6m right now, but I think if I can extend it to 10m it will still hold
a small yagi.
Telescoping sections take less space.
4. Would a 10m mast with a single VHF or UHF yagi be too heavy to lift on my own (in case no one is around to help)?
It depends how you try to lift it. If you extend a 10m mast and try to tilt it up into place you will
find it quite difficult. I've seen a number of the US steel push-up masts break when used this way
due to the weight of the load and the upper mast. Tilting up a mast puts more stress on it than
But I've put up my mast sections to 40' ( 12m ) by myself, and it isn't difficult if you know how.
First, the mast sections have to be SHORT enough. Mine are 4' ( 122cm ) which is about right, and
I'm fairly tall. It would be more difficult with lengths more than 1.5m without having a ladder, and
1m lengths would be even easier (though it would require more of them, of course.) The choice will
depend on the lengths available to you.
The key is to erect the mast vertical when it is retracted (or has few sections), then extend it in
place. I typically mount the antenna on two sections of mast ( 2.5m ), tie off the guy ropes to at
least two of the anchors, set the mast upright, then walk it to where the two guy ropes are snug
enough. I should be able to lean it gently against the two ropes and have it stay upright.
Then I get the next section handy, lift up the mast with one hand (while keeping it leaning against
the two ropes), slip the new section underneath, and set it back down. The secret is that you have
to keep moving the base of the mast closer to the guy anchors as you do this. Just keep repeating
this process until you reach the desired height, then tie off the third guy rope. (You may want to
adjust the guys if you want the base of the mast in a particular location, as it is difficult to get the
guy rope lengths and anchor points exactly right initially. It takes some practice, but is simple once
you get the feel for it.
To take it down, reverse the process.
If you are putting up a large antenna it probably is best to set up just the mast by itself first, get it
positioned where you want it and the guy ropes properly adjusted, then lower it, put the antenna on,
and put it back up in the air.
When we did the big 15m yagi we had three people lifting the mast and one keeping tension on the
third guy rope. Unfortunately he didn't understand the process and keep pulling the rope tight,
making us have to work harder to lift the antenna.
I'd use the same approach with a telescoping mast - put the antenna on, tilt the mast to vertical,
then extend it one section at a time. This requires that you be able to reach far enough above the
clamp to push the sections up, so 2m sections will require something to stand on. Also, paint or
otherwise mark the lower part of each section to warn you to stop pulling, otherwise you may
pull the whole section out of the mast. At that point it may be difficult to control.