Pneumatic Antenna Launching Systems
Pneumatic Antenna Deployment Systems (PADS)
My First Pneumatic Antenna Launcher - They are much smaller now, see below
News and Updates
- 2/06: New - the PADS Web Page are up and a new PADS
Kit is on the Order Page.
- 1/06: Have returned from Quartzsite.
Quartzsite was a lot of fun, plan to do it again next year!
Will work through existing orders.
Have received new stock of 2.5" SDR21 barrel material.
- 1/06: Super+Zip Kits added.
The Zip Reel is included in place of the fishing reel mount in the Super-II kit.
The Zip Reel is assembled and preloaded with 150 yards of Spectra line.
- 1/06: Super Kits upgraded to Super-II kits by adding the pressure safety relief valve
and the 1/8 NPT Tap. The tennis balls supplied now are new (previously they were used
in good condition). As before, these kits contain 3 Prepared Tennis balls, a Ramrod kit,
a Reel Mount, the Epoxy kit and the Launcher Parts Kit.
- 12/05: I will be attending
Quartzfest at Quartsite the week of January 22-28.
Emails during that time will probably have to wait, I do not expect to have internet access
from the desert!
I will be doing a Pneumatic Antenna Launching presentation at 10:30 on Thursday morning.
Hope to see you there!
- 10/05: Lately there has been some interest in launching antenna wire directly
towed by the ball. This has been done succesfully. More testing is likely ahead.
The wire must be strong and light, AND THERE MUST BE NO POWER LINES in the vicinity.
The Zip Reel will feed small wire pretty well, but more testing is indicated.
Range of the launcher is of course reduced. A weaker section of line should be tied
between the ball and the wire to facilitate getting the wire back even if the ball
catches. When enough data is available a separate web page may be prepared.
- 10/05: Received an invitation to the Southwestern Convention in San Diego 2006,
so we'll probably do a presentation down there.
- 9/05: NEW Field Test Results for CSV19 and CSV17 - measurements with the
two new demo launchers and the new Teflon coated Line.
These are the same as the kits currently shipping, with SDR21
barrels. The weather was cool and sunny, and the elevation was 5000 feet.
CO2 was used. The
projectile was a 4 ounce ball, the reel was Eric's Zip reel loaded with 50 pound
teflon coated Spectra line. The CSV19 was filled to 50 psi and the ball launched
154 feet. The CSV17 was pressurized to 80 psi and the ball flew to 159 feet.
These heights do not include the 10 feet of height of the muzzle, they are a measure
of the line towed up by the ball.
- 9/05: Launchers in Finland - there has been a lot of interest lately from Finland
in the launchers. Shipping to Finland adds about $20 to $50 (in addition to normal shipping
rates) depending on weight
and mode. Surface shipping is quoted as 4 to 6 weeks, Airmail is 4 to 10 days.
If buying a kit don't forget a tap as those are probably not commonly available
there. We cannot ship PVC cement, but there is a locally available cement that
is designed for PVC and has worked out well. It is made by TANGIT and is the
variety made for PVC-U (rigid PVC). (Thanks to Benny OH9NB for the cement tip).
We can ship the epoxy, so the Full Kit is a good choice. Add the tap, perhaps a Zip Reel,
or your fishing reel and line, compressed air and go! (Assembly required).
- 9/05: We had a good time at the SJVARS Harvest Hamfest. We did a
presentation and there was a lot of interest.
- 9/05: We have obtained some schedule 80 1" PVC pipe for the chamber to
valve connection on the CSV19 and CSV17. This increases the strength of
the launcher.
- 9/05: Updated the photo of the CSV19 below. The new photo is of my new
model built with the current parts, so what you see is what you get, if you
order a kit here. It has the new cable tie and spacer strengthening the barrel
to chamber. I am experimenting with spacers - at the moment I'm using 3/4"
dowel. (Update - now using a small block of grey PVC).
- 9/05: Further reduced graphics content (made clickable links for some photos).
I also put together a Python script for uploading the website. It figures out which
files are changed and loads only those to the site. Very convenient, and it will
help me update the site more easily and more often.
- 8/05:
We will be at the upcoming San Joaquin Valley Hamfest with a presentation on Launchers.
SJV Hamvest Site
My wife will have a Cookie Lee Jewelry table, and I will be there part of the time.
Come by and see us. We will also be at Pacificon.
Pacificon Site.
- 8/05:
We have one report of a CSV launcher breaking by dropping it. I now have some tooling
to drill out and replace the snapped off 1" pipe. To increase the strength of your
launcher it is advisable to put a spacer between the barrel and chamber and a
nylon or velcro cable tie around the barrel/chamber to hold them together.
I will supply this on future units and kits. The difficult part is the spacer -
it needs to be different heights depending on how your launcher is glued up.
I can supply the cable tie and a nominal spacer, but there may be some adjustment
required in the spacer's height. If you have a launcher that is broken we may
be able to repair it, or drill out the sockets so you can. Contact me via email.
- 4/05: We had a good time at the recent DX convention in Visalia. Met quite a few
folks interested in Antenna Launching.
If your DXpedition location has tall trees the little CSV17 launcher would
make a good tool.
If you like to do a little DXing from portable locations you can put up some
impressive antennas with a launcher and some good trees. We have done Vee beams
that were higher performance than just about any practical commercial beam.
Even a dipole has pretty good low angle radiation when it is 100 feet above ground
on a hill with local terrain falling off. The noise levels are usually lower
as well.
- I have been working on a smaller launcher called the CSV17.
It is a 17 inch version of the CSV19 and it has a 3" diameter chamber instead
of the CSV19's larger 4" chamber.
The smaller launcher fits nicely into an available hard case, perfect for travel.
The CSV17 works well with a 12 gram CO2 cylinder using a bicycle
tire filling adapter.
It also pumps up very fast with a hand or foot pump.
The CSV17 will easily reach 150 feet plus with a 4 oz ball towing line.
The CSV17 is available now on the order page.
The CSV17 in a case is called the PADS - Pneumatic Antenna Deployment System.
This is available in Kit form, see PADS Kit.
- If your ham club would like a presentation on Pneumatic Antenna Launching Systems,
and it is not too far away from Berkeley, CA drop me a line.
We did this at Pacificon and it was well attended.
- We generally attend the Livermore flea market and the NORCAL QRP meeting
on the first sunday of the month, and bring along our launcher (and balun)
kits.
We've also attended a FARS Ham-Tech Day at SLAC recently:
www.fars.k6ya.org/events/amtechday.shtml
and will probably go to some of these in the future.
If you can attend one of those events to pick up your parts it will
save the shipping and handling. Let me know ahead of time so we will have the
parts and make sure we meet. I also generally attend the Dayton hamfest though
I may not be able to bring too much along on that trip.
We usually attend Emcom West, and Pacificon, Visalia and the SJVARS Hamfest.
- We now have 2.5" SDR21 PVC pipe. This is slightly thinner than Schedule
40, is rated for 200 psi and fits tennis balls very nicely and weighs a bit less.
It is quite smooth inside.
We will be using this on most launchers and kits. Great stuff!
If you are interested in getting some of this material see the
Online Order Form or drop me an email.
- See the Recent Progress section below for older News and Updates
FAQ - Frequently Asked Questions
What is Pneumatic Antenna Launching?
Pneumatically Powered (Tennis Ball) Antenna Launching.
Pneumatic Line launching is perhaps a more apt description.
First we need a line in the trees, then we can pull up an antenna, which in
most cases is a long piece of wire.
In the launcher pictured above a Tennis Ball is propelled by compressed air,
towing a fishing line over the tree.
Then we pull up nylon mason twine with the fishline, and finally a wire
or heavier line as needed.
Why does anyone need to Launch an Antenna?
It is often more convenient to use existing trees than to erect supports for
wire or beam antennas, especially when these antennas are required for
temporary or emergency field use.
We set up antennas for disasters and drills, camping and contests,
practice and fun.
With all the applications for Homeland Security there are many potential
uses for rapid deplyment.
If you have a need to quickly set up antennas in various field situations,
or you have some really nice trees in your backyard,
you may have a use for Antenna Line Launching.
What is a Pneumatic Antenna Launcher?
It is a very simple system that uses the energy in a pressurized volume of
gas (generally air), a valve to release the gas, and a projectile (tennis ball)
in a tube that is accelerated by the expanding gas giving it the requisite
velocity to pull a light line over the tree.
Why not use a ... (Slingshot, Bow, Rock, Stick, Crescent wrench, Blackpowder Cannon, 12 Gauge)?
We have used many different systems since the 70's to put lines up into trees.
Each system has advantages and disadvantages.
Throwing an object over a limb is the easiest, but will not reach very high,
and there is a significant chance of getting the object stuck.
Slingshots reach higher, and Bows reach higher yet.
The main problem with all these systems is the projectile.
A lead sinker, arrow or crescent wrench can do a lot of damage if it
lands in the wrong place.
If you are putting a line over a tree in your yard, there are often
local ordinances against using slingshots and bows.
What is needed is a really safe projectile, and a means for getting it
over the tree precisely for maximum safety and effectiveness.
If you have a really tall tree, then a Tennis Ball Launcher will allow
you to go higher than most slingshots or bows.
Even a small Pneumatic Tennis Ball launcher can reach up more than 150 feet,
and it is possible to go much higher with the more effective models.
No, We did not try the Black Powder Cannon.
I recall seeing an article about that in a major magazine years ago.
I think we've found a safer solution...
And the 12 gauge - we've heard details, but don't try that one either...
My slingshot/bow works fine, why consider a Pneumatic Launcher?
You might consider a Pneumatic Launcher if you are interested in more
Performance or greater Safety. Slingshots and Bows work, but Pneumatics
work better. Eric's big launcher can put a tennis ball up over 600 feet
high (with no line). The small CSV19 reaches up to 200 feet towing line,
and the dimunitive CSV17 goes up to 150 feet towing line. These
launchers are 19 and 17 inches long, respectively, and the heights
are measured length of line pulled out. Add about 10 feet to those
numbers to get the apogee, since the reel is about 10 feet off the ground
when launching upwards. You can make launchers go higher, and we have,
but the availability of trees that tall and feedlines that long makes
it rarely useful. So I scaled the pneumatics back to the smaller sizes.
Also be very careful with the slingshot and bow, there are many
injuries each year, especially with the slingshots.
If you are going to put up an antenna in the backyard the tennis ball is
a lot safer than a lead sinker, and much easier to explain to your neighbor.
Why use a Tennis Ball?
There are three primary reasons to use Tennis Balls.
Safety, Safety and finally, Safety.
I have read of so many accidents with slingshots this year that I cannot
recommend them.
A lead sinker flying through the air is potentially an accident waiting to happen.
They bounce off the tree, the line snags and the sinker returns on the line rebound,
or they get hung up and come sizzling down when the line is pulled, potentially at
higher velocity than even the slingshot can impart.
The slingshot is not the problem, the projectile is the problem!
A Tennis ball is inherently a fairly safe projectile.
They are big so they slow down quickly, limiting the distance they
will travel and the velocity they impact with.
They are not hard, so they tend to do little damage when they land.
It is something familiar so people know what to expect.
It is big enough to see fairly well.
They are available and inexpensive.
How High will these Launchers reach?
150 to 200 feet of height is easily attained with a Pneumatic Tennis Ball
Antenna Launcher while towing a 50 pound test fishing line.
It is possible to go much higher with the more efficient or larger launchers,
but we have not found suitable antenna trees much over 130 feet tall.
So we consider 150 feet to be about optimal.
Are these Launchers Dangerous?
If you've played or watched tennis you know that the serve is (usually) one
of the harder hit strokes in tennis.
Well, a good serve has more velocity than is required for launching
a tennis ball over most tall trees.
The ball slows down quickly, and on the far side of the tree (towing the
fishing line) it comes down very slowly.
The simplest material for building an Antenna Launcher is Schedule 40
pressure rated PVC.
This material is designed for working pressures in excess of 200 pounds per
square inch, and the pressures we use are up to 60 or 80 psi.
So while the pressures are within design parameters, the manufacturers
of PVC pipe and fittings RECOMMEND AGAINST its use with COMPRESSED AIR.
If PVC containing compressed air is fractured, it may result in high velocity
PVC shrapnel.
So avoid breaking it while it is pressurized, and wear safety glasses
when using launchers or any power tool. Low and high temperatures make PVC brittle or
soft so launchers should not be used in extreme temperatures.
Are these Launchers Regulated? Aren't they Illegal??
The Federal BATF (Bureau of Alcohol, Tobacco and Firearms) has ruled that pneumatic
launchers are NOT firearms.
Some Municipalities have regulations that may affect the use or ownership of
Launchers. Such rules are not common, and the ones that do exist usually focus on
combustion type launchers rather than pneumatics.
Check with the local authorities to be sure.
Note that slingshots and bows are generally illegal to use in residential areas,
parks, campgrounds, etc.
How much does a Pneumatic Antenna Launcher cost?
The materials for a launcher cost between anywhere from about $60 on up, plus a
fishing reel, some line and a few tennis balls. If you have leftover parts
from a lawn sprinkler project it may be much less... Launcher Kits
are available for under $100, see the Online Order Page.
How hard is it to build a Launcher?
It depends on the model, and it ranges from fairly simple to quite complex.
If you can cut and glue PVC and thread pipe fittings together you can
build the simple models.
Some require drilling and tapping a hole or two in the plastic,
some need a little soldering.
Kits are available for some models, so the hard parts are already done.
The time required varies from a few hours on up.
The more complex designs may require a friend with a lathe to machine some PVC.
Generally speaking, as size/weight/cost go up, so does performance.
A low performance design might require 80 psi to launch 150 feet
high, whereas a higher performance design might do the same job at
25 psi.
Choose a design that matches your construction ability,
budget and size requirements, and the trees you need to launch over.
What kind of Pneumatic Antenna Launcher should I build?
Eric (WD6CMU) and I (Alan WB6ZQZ) have been experimenting with Tennis Ball Launchers
since 2002.
We have built nearly a dozen different models, and I have written software that
analyzes and predicts performance.
A couple had insufficient performance, and some others had
excess performance.
(Excess performance is not always a problem as it does allow
operating at lower pressures, but it may mean that the Launcher
is larger and heavier than it needs to be.)
We seem to be settling on about sixteen inches of barrel length,
a 1" sprinkler or 3/4" pneumatic valve,
and approximately 60 to 100 cubic inches of air storage.
This produces a launcher that weighs in the neighborhood of
five to seven pounds,
and produces sufficient performance at about 40 to 60 psi for most launches.
The barrel material is 2.5" schedule 40 PVC, into which a tennis ball
fits very snugly, or 2.5" SDR21 PVC into they fit nearly perfectly.
To get specific I will mention some of our models,
- The CSV19 and its smaller sibling
the CSV17 are fairly simple to build,
and are available in kit form. This may
be the best compromise and we provide the most detailed information on building
this unit, as well as partial and full kits of prepared parts
on our Online Order Page.
- The U37 and DU36 U valve models are simple to build but
are a bit larger than some of the newer designs. The original QRP Quarterly
article describes building the first (electric) version of this model (U37)
in some detail and the pdf is available here. It was designed to fit between
the wheel wells of a Toyota 4Runner and is 37" long. I later modified this to
pneumatic triggering and it became the DU36.
It will not fit in the Rubbermaid(tm) tote boxes that we use for our newer designs.
- The Field Day 2003 special is not hard to build and does not require
exotic tools. It is a bit larger and heavier and more expensive
than the newer smaller models.
There are some pictures and info here for
the Field Day 2003 Special.
It also will not fit in the Rubbermaid tote due to the overall length.
- The QE19 Quick Exhaust Valve design is the simplest to
build and is fairly
lightweight and small but requires a bit more air pressure to operate.
The 3/4" Quick Exhaust valve limits the airflow somewhat, but it does reach
up to 150 feet of height at 70 psi, and it can safely take 100 psi.
Due to all the brass parts the cost is somewhat higher as well, but there is no
need to bore, drill or tap PVC so construction is straightforward and few tools
are required.
- Eric's Trident design utilizing the soda bottle pressure chamber is the lightest
but has some difficult to make threads, and the pressure needs to be kept low to
protect the chamber.
- The DV19 Dual Valve is complicated to build but does not require exotic tools.
It has very high performance. Due to the high parts count the cost is on the high side
and the weight is high also. It still fits in the Rubbermaid tote, but
nearly fills it up. The high performance allows reaching tall heights at low air
pressures. I do not provide detailed instructions on building it, but there are
several photos in the Tale of
Two Launchers page.
- The DFTV19 Turbo Valve requires a
lathe to make the parts.
It also provides very high performance. Due to the custom made parts the weight is
quite low and the cost is low but the effort required is high.
- The Spud Tech TB500LP is commercially available. It is a bit larger and
heavier than our current models but should do the job well.
The PADS17 Pneumatic Antenna Deployment System with Accessories
What is a Pneumatic Antenna Deployment System?
This is the name for the Launcher-in-a-Suitcase shown above.
This scaled-down launcher fits nicely into this hard case.
The launcher and hard case are available on the order page.
Also shown are a pair of Twine Reels containing 500 feet of
nylon twine. They are available in 270 foot lengths as well.
The grey cylinder near the bottom center of the photo is a
bicycle type CO2 tire inflator. It can be used
with a number of different capacity CO2 cylinders.
Using the low-cost 12 gram cylinders produces enough pressure
for one good launch per cylinder. Also in this case, but not
visible is a 12 oz Paintball CO2 cylinder stored
inside the barrel, along with two tennis balls. The CO2
pressure regulator is behind the right end of the ramrod.
There are a total of six tennis balls in this photo, two hidden
in the barrel and one hidden inside the reel on the lower left.
The reel on the lower left is a prototype we are working on.
It may be available later if it meets our requirements.
Just behind the launcher's trigger is a bag of 12 gram CO2
cylinders.
See the PADS Web Page.
What about a Ball-valve type launcher?
The simplest pneumatic launcher is a pressure storage chamber, a barrel, and a
ball valve in between.
These are not particularly suitable for antenna launching because the
performance is dependent on how quickly the valve is opened.
Additionally, opening the valve manually disturbs the aim, so it
will be difficult to make it go where desired.
What about a Combustion powered launcher?
Combustion type launchers use lighter fluid,
spray deoderant, propane or some other fuel
in a closed pipe chamber behind a projectile with an ignition source to light it off.
In addition to some safety concerns, combusion launchers may produce somewhat
inconsistent shot-to-shot performance, which makes them difficult to
use as a serious Antenna Launching tool.
They also misfire occasionally and are more often regulated than pneumatic
systems.
Let's not use them for Antennas!
How Small and Light can an Effective Pneumatic Antenna Launcher be?
First, I'll define 'effective' as any launcher that can toss a 4 ounce
tennis ball to a height of at least 150 feet towing a fishing line.
That is pretty adequate for our purposes.
The smallest launchers that meet this criterion that we have built are the
Compact Low Cost Sprinkler Valve Antenna Launcher
and the Quick Exhaust Valve Launcher.
At about three to six pounds, these are small enough to fit into a Rubbermaid
tote box, or less than 19 inches in length.
There is plenty of room left in the tote box for line, antennas, feedline,
and other equipment.
The CSV19 Compact Low Cost Sprinkler Valve Antenna Launcher
is assembled from plumbing parts most of which are available from local
plumbing or home improvement stores for under $100. Some machining is required to make them
fit together as shown above. The dark grey barrel is SDR21. Schedule 40
also works, but the ball is very tight. SDR21 fits better but is harder to find.
This is the lowest cost simple to construct launcher I have designed.
The link above has fairly complete construction instructions.
The collection shown above is shown complete with
Saunders Zip Reel with yellow Spectra type synthetic line, and a couple of prepared
Tennis Balls sitting on a Rubbermaid 10 gallon tote. The gear fits into the tote
with plenty of room to spare.
QE19 Photo
The QE19 Quick Exhaust Valve Launcher
is the smallest and lightest of my launchers.
It is based on an industrial quick-exhaust air valve (the silver item above).
This is the easiest launcher to build,
but due to the industrial and brass parts costs somewhat
more than the model above, about $100.
The link above has construction information.
This launcher is sitting on top of one of the Rubbermaid (tm) 10 gallon tote
boxes that I use to carry equipment to field.
There is room for lots of gear in there in addition to the launcher.
The lightest launcher we've done to date for Tennis Ball Antenna Line Launching
is Eric's Trident which uses soda bottles for the
air pressure reservoir and weighs a litte less than five pounds.
Eric also came up with a nice mount for an archery fishing line reel that fits around
the barrel and feeds line very smoothly.
Check out Eric's website at
www.qsl.net/wd6cmu for his Saunder's Zip-reel mount and Trident Launcher.
The Launcher on the left is the Quick Exhaust model, here shown in the 28 inch configuration with a spinning reel mounted just below the forward end of the barrel
(hard to see against the foliage in this photo).
This photo was taken before it was shortened to the 19" version shown above.
The two launchers in the photo were used on Field Day 2003 to put up numerous antennas.
Field Day is an Amateur Radio 'Emergency Drill' essentially, setting up and operating in field conditions for a couple of days.
It is a lot of fun and a good test of our equipment and technique, both radio and Antenna Launching.
More Pneumatic Antenna Launcher Examples
High Performance in a compact package: DV19
This model packs a pair of one inch sprinkler valves in to a Rubbermaid sized tote package.
It doesn't take much pressure for this unit to reach 150 feet of height!
Building this is quite a challenge with all the plumbing parts packed in tight.
There are the two 1" sprinkler valves, a quick exhaust valve trigger, two check valves, a paddle trigger valve,
and some specially adapted (shortened) PVC fittings. It was made with fairly minimal tools - a drill press and a belt sander, plus a radial arm saw. None of these tools are
absolutely required - this design can be made with hand tools.
It is a bit heavy, around 10 pounds. As shown below it includes the Saunders Zip Reel
and a removable barrel extension that improves the efficiency of the launcher.
For more info on this launcher see
A Tale of Two (Compact) Launchers.
DV19 Photo
Ultra Performance in a Compact Package: DFTV19
This six pound model packs a tremendous capability in a very lightweight package.
It fits in the Rubbermaid containers as well. The Darn Fast Turbo Valve is a 1.2" ported
homemade piston valve with a self-venting and turbo actuation features that
make it low cost, light weight, and incredibly effective. The only disadvantage
to this design is the requirement for precision machined parts in the valve.
I purchased a small lathe (www.Grizzly.com) and made them with no prior machine
shop experience, so it isn't all that hard.
More info is available in the The DFTV Story.
DFTV19 Photo
More Examples can be found via links in the "More Information" section below.
How is Launch Pressure developed?
The pressures and volumes involved are similar to a bicycle
tire, so automotive or bicycle air pumps are just about right.
The portable 12 volt electric ones are great.
They run from a car battery or are even more portable with a Gel Cell.
Hand or foot pumps work well also, and have the benefit of a good
aerobic workout.
Some folks use CO2 systems which are very convenient at greater cost.
I recently have been testing two CO2 systems - a Paintball cylinder
and regulator, and a Bicycle tire filler using 12 gram cylinders.
CO2 systems cost a bit more to own and operate, but they are pretty
amazingly effective and fast.
I tested a 6 gallon compressed air tank recently and starting with 100 to 110 psi
was able to get about 15 shots at 50 psi from it with the CSV19 launcher.
The smaller chambers on the CSV17 and QE19 would get even more launches per fill.
Here is a portable battery powered filling station similar to the one I have.
This has become a favorite for charging the launcher. It takes about one minute.
Mine has a 12 volt 17 amp gel battery and a compressor and was under 50 bucks
at Harbor Freight tools.
After you launch the antenna you can hook up to the 12 volt gel battery and
run the station!
Jumpstart Box Photo
Detailed Antenna Launcher Construction Articles
The
Compact Sprinkler Valve and
Quick Exhaust Valve models
have fairly construction details on their web pages.
I wrote a complete construction article on the TBL-U37
pictured above (lead-in photo and electric actuated above).
It was published in the QRP Quarterly magazine, Spring 2003.
A pdf version is available here.
Note that changing to pneumatic actuation makes a large
performance improvement in this launcher. A similar
launcher that has good performance is the Field Day Special.
Information on this model is available on the
Modelling page.
Can I buy an Antenna Launcher already built?
Joel has a premier website and builds launchers:
The SpudGun Technology Center.
He sells components and complete units.
Look under his "Launchers, Low Power Pneumatic" links.
His TBL500LP with a 24" barrel and 12" by 3" chamber is about the right
performance level and size.
(Disclaimer - I have not used any of his launchers.)
We can also build launchers, see the order page for details.
Recent Progress
- I am still working on a Compact Coaxial valve launcher. This project started
quite some time ago but has been building steam and most of the parts are made.
I still am working out a few kinks before final assembly but that should begin
soon. The flow of this valve is six times the flow of a 1" sprinkler valve, so
the performance should be impressive. I don't expect this launcher to be easy
to reproduce due to all the components and machining required. It will show us
what can be accomplished in a small overall length package. (note this work
is again on hold. 5/05)
- Pacificon 2004 has come and gone now.
They changed the time of our presentation twice, so some folks probably missed
it (I nearly missed it myself!).
Our presentation started out in the dark via flashlighting,
since there was a local area power outage,
and halfway through the lights came back on so we were able to show some of the slides
and the video.
We will be putting the video up on the web soon, hopefully, though it is a bit large.
Here is the slide show in pdf.
I am also working on updating the CSV19 web pages.
Thanks to all that attended and came by and chatted with us.
Here is the Pacificon Website.
- CSV19 Kits and Mini-Kits - I have Kits and Mini-Kits for the CSV19 launcher
to help you get a quality Antenna Launcher going with less effort and fewer tools.
The
Mini Kit includes the hard parts - The ones bored out on the lathe - so folks can
duplicate this design with basic tools. This includes the prepared sprinkler valve,
the bored end caps and the fitted parts that go with them.
Visit our new Online Order Form or the
CSV19 Antenna Launcher pages
for more details.
The remaining parts can be found in hardware stores, or in the full kit,
which is also available.
- The Mini CO2 Charging System is working quite well.
I have been using 12 oz paintball
CO2 cylinders with it, and getting lots of launches (approx 30) from one $3 fillup.
It gets a bit cold if it is used in cool weather, but it has not been a problem
at the low rate of launches that we usually need. This is certainly not
a required Antenna Launching accessory but it is extremely convenient.
Several tests conducted
have not found much difference in height between CO2 and air at the same pressure.
We have added this to our new Online Order Form.
- The Berkeley Gorilla line has been reaching about 20% higher height than the
previous Dacron twisted kite line. I suspect that the lines work best when new,
and as they get a bit fuzzy the height is reduced due to drag. I got 35 pound test
Gorilla Line at Wallmart, but next time I think I will follow Eric's lead
and get the 50 pound test variety.
- 11/04: Finally found SDR21 barrel material! It is thinner, lighter
and rated to 200 psi instead of the 300 psi that 2.5" schedule 40 is rated for.
It weighs about a half pound less in a 16" length, so it will be noticeably
lighter than the schedule 40. Eric did some testing and it helped the launch
height at low pressure but made no difference above 100 feet or so. Drop me an
email me if you are interested in some 2.5" SDR21.
- I have really been enjoying the CO2 system. I get about 30 shots from
a 12 ounce paintball bottle. That is more than we used on Field Day this year,
and we put up a lot of antennas.
- 7/04: How would you like to pressurize your launcher
in 5 seconds with a several pound 'charger' that you can carry around with
you or even mount to the launcher? I'm working on a couple of different
systems for this, all based on CO2. The key to this is two things -
refillable paintball CO2 cylinders and a top quality pressure
regulator.
Since CO2 is around 800 psi we need a pressure regulator for safety and
practicality. The Low Pressure (0-300 psi) version of the Palmer Pursuit
Female Stabilizer is designed to mount directly on the paintball bottle
screw threads and regulate the pressure. It is available in a number
of configurations, the most convenient of which has a schrader tire filler
valve directly mounted. This is plug and play CO2! You order the
'tire stabilizer'regulator
and one or more bottles from Palmer Pursuit, take the bottles to the local
paintball CO2 filling station to get it filled, screw on the regulator and
start filling your launcher. The small launchers we are using currently
get about 2 to 5 launches per ounce of CO2, so a 12 ounce CO2 bottle will
give you about 25 to 60 launches. You can get up to 20 or even 24 ounce
bottles for more capacity, and of course can have several bottles on hand.
I selected the 12 ounce as a good compromise between size, weight and
capacity, though the the 20 ounce was very tempting as well. The 8 or 9 ounce
bottles are really convient and small, so you have to decide!
The cost for CO2 around my area comes to about ten cents per launch.
I'm still going to use a compressor for my megalaunching testing sessions, but when
doing actual field antenna work it is quite inconvenient to have to trudge back
to the compressor each time. It is also safer to pressurize right at
the time of the launch, and minor leaks are not so much of an issue.
In addition, the whole launching system, including the CO2 system will fit
into the Rubbermaid tote along with the launcher.
- 6/04: My Turbo Valve launcher is leaking again.
Based on this, I can't really recommend using cyanoacrylate with PVC.
It seems to get a good joint, but fails later.
I had only used the CA to seal some leaks, but it failed even to
do this on a reliable basis.
My first repair of the repair with epoxy has been 85% effective.
I think I will have to set up to use vacuum to draw the cement into the
cracks for a better result.
- Field Day 2004 was a great workout for the launchers. We used three of
my launchers and Eric's Trident (but using only one bottle) and put up
two HF beams, a 40 meter sloper and a multiband inverted Vee.
Eric's CO2 system worked well. My little compressor took longer and made
more noise. Have to check into a CO2 upgrade...
We shot some video and are deciding what to put on the websites...
- The Dacron kite line seems to grab too much air and have too much friction
on the tree. I'm going to look into the higher tech fishing/kite lines
as they do seem to perform better.
Where can I get More Information about Pneumatic Antenna Launchers?
There is a lot more info on the web.
Most of it is not directly Antenna Launching related, but much can be learned there that is applicable.
If you find the information on this website useful and have a website of your own,
please include a link to this page to help others find it.
If you have related information and want a link here on my page drop me an email!
Other Launcher Construction Websites (Not necessarily Antenna oriented)
Or Search the Web:
The following links perform Google web searches with various arguments that produce lots of hits for this topic.
since July 2003
Alan's (WB6ZQZ) Home Page
e mail regarding this page to Alan via wb6zqz at arrl dot net