[Elecraft] [Antenna launcher

[Fred Townsend]

Gary I'd like to 2nd your comments and add a few of my own. 

Re tennis balls I add sand and it's easy and cheap. 

You can always bore-sight your target but I added a sight to my blaster. Now
I am one shot, one kill.

If I have to shoot very close to my target tree, because of nearby real
estate like a power line or fence, I lay on my back and shoot near vertical
over a 100' tree.

I have found, for fun and games, a filled 8 oz plastic water battle works
well. It's the same diameter as a tennis ball. It makes big splash on
impact. Gets rid of annoying dogs too. You don't need to hit them. Just
close enough to splash.

73,
Fred, AE6QL
-----Original Message-----
From: Elecraft [mailto:elecraft-bounces at mailman.qth.net] On Behalf Of Gary
Smith
Sent: Monday, February 09, 2015 1:54 PM
To: Elecraft at mailman.qth.net
Subject: Re: [Elecraft] [Antenna launcher

Nice web pages. 

I discovered a couple of things that to me are important when it came to
launching these projectiles to get wires over the tops of trees:

- A heavier weight is better than a lighter one such as a tennis ball when a
50 pound fishing line is attached, because a light weight object will get
hung up on branches and the inertia from a heavy object falling to earth
will bore its way straight through the branches and leaves. I painted the
white PVC with red spray and on one I used red/white reflective tape. This
makes it easy to find where it's landed in both summer and winter.

I ended up using 50 pound test monofilament line because the amount of
branches I have to contend with end up being enough friction resistance that
I was breaking lighter line. With the 50 pound test line I can bring my WD
1A telephone wire up and through the branches in one attempt. 

- a long barrel is far preferable to a short barrel because the addition of
the eye on the end of the barrel prevents the line from flailing as it is
being expended. If you try throwing a fishing line without a pole & the eyes
to guide the line coherently as it's being expended, you will not throw it
far. Attach eyes to a broomstick & lightly toss & it will go much farther.
The eye is a must if you want distance. 

- In addition, a longer barrel will give you a greater distance, just like a
rifle will shoot farther than a pistol with both using the same ammunition.

- When putting the PVC spud in the barrel, the line & swivel end goes in
first, otherwise the drag from the line will make the projectile and invert
on the way up spin like a top. That can be problematic when coming down as
you don't want it to get hung up on top branches and if it's spinning like a
propeller, it will hang up sooner than later.

FWIW, With no line attached I can shoot a 4" long projectile well over 1/4
mile of water without touching water. With the line attached such distance
is quite impossible thanks to the drag, even with the eye in place. 

I figured I'd mention this tool here because of so many people on the
Elecraft reflector enjoying remote operations with their QRP gear, this will
help tremendously with the antenna end of things.

73,

Gary
KA1J

> On Mon,2/9/2015 12:07 PM, Gary Smith wrote:
> > To get a wire over the tallest tree on the first attempt and that 
> > includes a Redwood, look at what I do at the bottom of my QRZ page. 
> > I got the idea from a QST article a few years ago and then built on 
> > the idea.
> 
> http://www.antennalaunchers.com/antlaunching.html
> 
> When I first moved to CA in 2006, K2RD brought one of these over to 
> rig my 80M dipole. His first shot cleared the tallest redwood on my 
> property by at least 25 ft. That tree is about 180 ft tall.
> 
> Here's another useful launcher for lower heights -- up to about 100 ft. 
> Buy it with the Zebco reel and attachment, and 10-12 oz throw weights.  
> You could use your own weights (fishing sinkers, for example), but 
> these throw weights are brightly colored cordura bags that make it 
> much easier to find on the ground after you've thrown them. My Chicago 
> club owns one that we used on Field Day and that was loaned to members 
> to rig their antennas.
> 
>   http://www.sherrilltree.com/Big-Shot-Standard-Kit#.VNkWwCvF_wk
> 
> 73, Jim K9YC
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