Topband: Ladderline: To Twist or Not to Twist?
Jeff Wilson
jjw5257 at yahoo.ca
Tue Mar 23 07:12:37 PDT 2010
My old Saxton Products C-4-100-6 ladderline used in my 80m Zepp and 160m top-loader vertical is showing signs of UV-degradation
Some of the plastic 1" spacers have cracked in half. So I am planning to replace it with new window ladderline.
I think I read somewhere that twisting the ladderline to minimize wind loading would impair the radiation efficiency.
Would this be a problem with the top-loaded vertical (shorted ladderline feed) or with the Zepp operation on 80m and down?
Do the antenna gurus of TB reflector have some words of wisdom for me before I rebuild and install my Zepp (aka doublet)?
Thanks
73
Jeff
VE3FRX
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Sent: Fri, March 19, 2010 3:00:33 PM
Subject: Topband Digest, Vol 87, Issue 20
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Today's Topics:
1. Re: 'Spud Gun' (David Hollander)
2. Re: 'Spud Gun' (Gary Smith)
3. Re: ZK3 on 160 picture (RICHARD SOLOMON)
4. Re: Spud Gun (Matt)
----------------------------------------------------------------------
Message: 1
Date: Thu, 18 Mar 2010 20:28:38 -0700
From: David Hollander <n7rk at cox.net>
Subject: Re: Topband: 'Spud Gun'
To: Jim - WS6X <ws6x at comcast.net>
Cc: topband at contesting.com
Message-ID: <4BA2EF66.6070904 at cox.net>
Content-Type: text/plain; charset=ISO-8859-1; format=flowed
I have been using an inexpensive wrist rocket (sling shot) for the times
I have had to shoot an antenna line over the trees. Used it with fishing
line and sinkers which have a hole through them so it is easy to attach.
I have been able to get them over a 60 ft tree without a problem
although it usually takes a few tries.
One the weight has fallen to the ground, I attach the nylon rope to the
fishing line with a square knot and tightly tape it so it won't snag
when going over the branches.
Worked well from the balcony of my apartment back in the mod 90's when I
was going through the big "D".
http://members.cox.net/n7rk/bigsig2.html
Just made sure I used the sling shot during the day when no one was
around. I'm sure someone would have called the police if they had seen a
grown man shooting a sling shot off of the balcony!!!!
73,
Dave N7RK
--
***********************************************************
Dave N7RK Boatanchors Home Page: http://members.cox.net/n7rk
Phoenix, Arizona *DXCC Honor Roll* *WAZ#22 - 75 Meter SSB*
ex-XE2/N7RK, N7RK/ZB2, VK2ERK, ZM0AJN, WB6NRK, WN6IWX
Boatanchor and Antique Radio Collector
------------------------------
Message: 2
Date: Fri, 19 Mar 2010 00:11:00 -0400
From: "Gary Smith" <Gary at ka1j.com>
Subject: Re: Topband: 'Spud Gun'
To: Topband at contesting.com
Cc: Jim - WS6X <ws6x at comcast.net>
Message-ID: <4BA2F954.28892.DD70D0 at Gary.ka1j.com>
Content-Type: text/plain; charset=US-ASCII
I don't want this to become an OT thread for Top Band, most people
here have fine antennae for 160M but some of us are antennae
challenged and make the best of our circumstances.
What I did was use the March 09 QST article as a base for the Spud
Gun and I did what I innately do & tried to improve on what was
described. I rarely... leave well enough alone...
So I uploaded some photos to my website so you can see what I have
described. Here goes:
http://doctorgary.net/spud1.jpg
In this photo I am showing the relationship of the valve and barrel
of my spud vs the one in QST. The one in QST is on the top and does
not have the trigger attached. I removed it as I want to drill out
the internal access hole and then epoxy the brass fitting in it, the
threads just don't match what the trigger needs. It was intact, I
needed a more permanent fixture and haven't put it in because I
prefer the larger gun.
I figured having a bore the size of the valve would do better than
having a valve that acted as a reducer. I have an adapter to allow me
to use the smaller barrel on the large valve and it is much, much
more powerful than using the smaller valve.
I wrapped the large one in tape out of my innate paranoia that should
a defect allow the pressure tank to explode, the duct tape would
prevent shrapnel. I did fill this with well over 100 psi while
covered in a sandbag and it holds pressure beautifully.
http://doctorgary.net/spud2.jpg
In this view you see the business end of the smaller valve. You can
see the larger opening, this is where the air trigger goes into.
Actually, the ideal place would be where the small 4 sided thumb-
screw is located but it is too small to be useful. The larger
circular opening is where the solenoid came from.
If you feel the need to use the smaller sprinkler valve assembly,
bore out the inner hole more than it comes with. You will need to
remove the brass fitting inside, it was designed to mate with the
rubber gasket of the solenoid and reduces the air inflow when you
fire the device & this will reduce the power it offers. ( the brass
fitting is already removed in the photo)
http://doctorgary.net/spud3.jpg
The larger valve beside the one in QST. I could have taken a more
inclusive photo but you saw the comparative difference in spud1. You
see the orientation and placement of the air gun trigger. I paid like
6-8 bucks for this air trigger at Advance Auto.
I paid $14 for the smaller valve locally at a lawn service wholesaler
in the area. I paid something like $30 for the larger one on ebay.
Where this was placed was at the pressure adjustment valve. I removed
the plastic bottom and drilled it out on a drill press to give me
maximum air inflow so as to allow the maximum FPS the projectile will
travel.
http://doctorgary.net/spud4.jpg
A macro of the trigger mount and the opening where the solenoid used
to be. You will see the white inside the old solenoid mount, that was
baking soda I filled it with and then put crazy glue on top of it.
This allows instantaneous cementing of the baking soda to the plastic
and seals off that area 100% which is needed to allow the trigger to
work where it is now placed.
I thought it might be more powerful to use a larger tank but since
this works perfectly to send a larger projectile than a tennis ball
or smaller PVC "Spud", I didn't need a larger tank which would have
required more pumping to fill. So you'll see both tanks are about the
same size.
Again, the spud this shoots is about one pound and the monofilament
is 30 pounds. The spud will not likely get caught in branches and
will fall to the ground. The 30 pound monofilament will not easily
break when pulling the antenna wire up.
IF you have a single tree to simply get over, anything will do but if
you want to get that projectile through a forest canopy and shoot it
through a small window above with accuracy, this is the cats A... to
do so.
Also, I have a 10 gauge goose gun, it has a very long barrel, much
longer than any other shotgun I have. That longer barrel gives a much
better range and far more accuracy than a shorter barrel. I made my
barrel longer based on that reason. IF accuracy is necessary, use a
longer barrel, if again, it is a tall tree to get over and there is
no small window of sky to get the wire through, a shorter barrel like
the kit mentioned earlier will surely be fine.
At around 90 pounds of pressure, it takes 12 seconds after firing for
the spud un-attached to the monofilament to hit the ground.
This will do the job...
And will drop that deer...
:)
Gary
KA1J
> ========================
>
> Message: 3
> Date: Wed, 17 Mar 2010 22:07:37 -0300
> From: "Mike & Coreen Smith" <ve9aa at nbnet.nb.ca>
> Subject: Re: Topband: suitable wire for top loading wires?-spud gun
>
> I'd love to see plans for that Spud Gun, Gary (or anyone)/.....I've been
> using a fishing rod for years but it's not entirely accurate and I've been
> "caught up" in the tops of trees more than once. I usually try to use some
> rocks taped to the end of my monofilament in case I have to yank and break
> it free.......then the rock drops to the ground. A spud gun sounds like the
> bees-knees.
> (and I could harmlessly target practice on the hoards of deer in the back
> field when not working on antennas! ;-) J/K ) Mike ve9aa .
> ,,,SNIP...
> I forget which month that Spud Gun was explained in QST, it was 1-2 years
> ago. I made one just like in the magazine but then I fiddled with the valve
> and made it a bit better. I then ordered a larger valve from Ebay. Either
> would work but I wanted a heavy duty version that would be sure to do
> anything I would ever ask of it. Minus the monofilament, that sucker would
> take down a deer at 300'...
>
> 73,
> Gary
> KA1J
>
>
>
> ===
> If anyone is interested, here's a spud gun -- I call it a "Squirrel Cannon"
> -- that I put together, borrowing from the best features of several designs.
> The unique feature about this design is that it uses a single, 10' piece of
> PVC. I've had a number of locals use this design with a lot of success.
>
> http://www.ws6x.com/ws6x_files/squirrel.html
>
>
> Enjoy,
>
> Jim, WS6X
>
> _______________________________________________
> UR RST IS ... ... ..9 QSB QSB - hw? BK
>
------------------------------
Message: 3
Date: Fri, 19 Mar 2010 04:47:29 +0000
From: RICHARD SOLOMON <w1ksz at q.com>
Subject: Re: Topband: ZK3 on 160 picture
To: TopBand List <topband at contesting.com>
Message-ID: <BAY130-W12DB8743DD01CDC7E4447CE02A0 at phx.gbl>
Content-Type: text/plain; charset="iso-8859-1"
Looks like the Cushcraft MA-160V (the one I have). Works great.
73, Dick, W1KSZ
> Date: Thu, 18 Mar 2010 17:10:54 -0700
> From: tree at kkn.net
> To: topband at contesting.com
> Subject: Topband: ZK3 on 160 picture
>
>
> Here is the antenna that the ZK3 operation is using on 160:
>
> http://www.kkn.net/~tree/160/zk3_160.jpg
>
> The radio is a K3 with no amplifier.
>
> Tree N6TR
> _______________________________________________
> UR RST IS ... ... ..9 QSB QSB - hw? BK
------------------------------
Message: 4
Date: Fri, 19 Mar 2010 17:46:29 +1100
From: Matt <vk2dag at arrl.net>
Subject: Re: Topband: Spud Gun
To: topband at contesting.com
Message-ID: <20100319064604.62264BEC045 at sv1-1.aanet.com.au>
Content-Type: text/plain; charset="us-ascii"; format=flowed
>
>In the Oct 09 QST page 20 there is a photo of a club that made them.
>They chose to use an inexpensive PVC "twist" valve to release the
>air, I thought about using one of those and probably should just for
>my own knowledge but I believe what I do should be better.
I just used the "twist" valve. Cheap and easy. It outperforms my
Ezi-Hang by far. I can get twice the height from the spud gun. Mine
is made out of high strength pipe that is not UV stabilized but I
figured that it wouldn't be spending that much time in the sun
anyway. I have 12 volt compressor and a small gel-cell battery and I
pump it up to 100 psi and pop away it goes. Best antenna investment
I have made yet. And my kids think it's the funniest thing going.
Shooting over 30m+ gum trees is a breeze. Now all I have to worry
about is the snakes when I am looking for the weight.
------------------------------
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