[TowerTalk] Fwd: Fwd: Temporary tower/antenna question

[Hans Hammarquist]

Jim, 


I secure the bottom of the pole, I'm going to rise, with two (or three if it's heavy) screw anchors normally used to hold dogs and horses. I put they around the bottom and attach them to the pole with cords. Maybe not so neat but it worked for me.


Precut guy wires are a "must" needless to say. I also use the same type of anchors for the end of the guy wires.


The guy point on the pole is at the ~40 foot and the ~20 foot level leaving the top few feet unguyed. Has worked without problems so far. No, i would not erect 48 feet a windy day. I have three of the Swedish "hogantenn". Use two for the end support of whatever I haul up in the taller pole and the third one in its original shape. Has a disc-cone antenna that works (good SWR that is) from ~ 26 MHz to well above 450 MHz


Hans - N2JFS



-----Original Message-----
From: Jim Lux <jimlux at earthlink.net>
To: towertalk <towertalk at contesting.com>
Sent: Sat, Feb 2, 2013 2:19 pm
Subject: Re: [TowerTalk] Fwd:  Temporary tower/antenna question


On 2/2/13 10:50 AM, Hans Hammarquist wrote:
> Use a 48 foot glass-fiber contraption, consisting of a number of 5
> foot sections. I think they were intended to be tent poles and not a
> 48 foot pole. Have successfully raised that using two guy point and
> FOUR sets of guy wires. Two guy sets are used to stabilize the set-up
> sideways, one guy set is used to stop the mast from falling over once
> raised and the fourth is attached to a falling derrick. The derrick
> was a 33 foot, sectioned aluminium tube used as a support for a
> "hogantenn" by the Swedish Army. Raised that contraption several
> times on my own (single handed) at several FD-s.
>
>


SOmething that I've found handy in speeding setup with "precut" guys is 
to have something that helps you place the guy stake/anchor in the right 
place, distance wise.

I'm very interested in speed of deployment and stowing when you're done. 
  If it takes 3 hours to get on the air, that's a very long time.  My 
personal criteria is 20 minutes from "wheels stop" to "ready to 
operate".. and I'd like to be down in the 10 minute range, so I've been 
fooling around a lot. The other criteria is everything has to fit in the 
trunk of the car or similar.  Hence my interest in collapsible poles and 
such.

I've done it two ways.  The first was to have strings that are the right 
length from base of pole to guy stake, and from guy stake to guy stake. 
  You set one stake, and then the two to either side.  But I found 
everything gets tangled.

The other was to put a knot or tape or flag in the guy line at the right 
distance to set the stake.  (Imagine you were guying a 40 foot tower 
with the stake 30 feet out, so the guy line is 50 feet long.. Put a 
piece of tape on the guy line at 30 feet from the stake. So you can walk 
out from the base and know when to plant the stake).

And, of course, if you have money.. I just got a cool handheld laser 
Leica distance meter at work which measures to 1cm accuracy from 100m 
away (taking into account tilt of the meter.. it measures hypotenuse, 
displays ground distance), and would make setting stakes trivial.
(http://ptd.leica-geosystems.com/en/index.htm)  (no more guessing how 
high that tree you're going to shoot the antenna over)

I'd love to find a material or packaging for lightweight guy lines that 
doesn't tangle or twist itself into a ball. Or a fast way to stow.  I've 
been thinking about some sort of lightweight springloaded cord reel, for 
instance.

Ditto for the wires of the antenna.  I got some very flexible hookup 
wire (very limp insulation, very many fine strands) which helps a lot, 
but again, some sort of reel or dispenser would be cool.


Here's what I think would be neat (given my crossed inverted V setup..)

Place the antenna base on the ground (pole collapsed).  run each guy out 
to the right place and stake/anchor it (sandbags).  The guy is connected 
to the end of the antenna wire.  At the top of the antenna is a sort of 
ring that the antenna wires go through.  As you push the pole up, the 
wire/guy feeds out.  So when the thing is all the way up, you've got a 
sort of uncontrolled open wire line to the base.

Say you want the inverted V to be approximately resonant on 20m, you 
want the wires to be 5m long from the top of the pole, which is 40ft/12m 
tall.  So the wires are 17m long, and there is about 6 m of insulating 
guy line on the end. (setting the guy anchors out half the height of the 
pole).

WHat I haven't figured out yet is (aside from the spool).. how do you 
hold the base of the pole steady.  I have a surveyor's tripod but that's 
big/bulky (fails the "fit in the trunk" criteria)... But that's sort of 
the idea. In theory, once the guys are up, it holds pretty well, so all 
you need is something to keep the base from sliding, and a couple 
sandbags would do that.

BUT, you really also need some intermediate guys.. That 40 foot pole is 
pretty flexible, and guying only at the top with the antenna wires makes 
for a pretty dicey setup.
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