Why Cantex ?

Why Cantex ?

Their material is UV-stabilized for weathering strength in the changing climate of Northern Ohio. It also machines and drills consistently. The dielectric constant is the same from piece to piece, and the Cantex compound resists chalking. I've filled a dumpster with look-alike parts that failed to survive the coiling process at some point.

See http://www.cantexinc.com for specifications.

The information presented here is accurate and true to the best of the author's knowledge. All recommendations and statements are made without guarantee on the part of the author. The author disclaims any liability in connection with the use of this information.

Monday, September 30, 2019

A first attempt at winding with 3/32" wire

Before winding, the tube is cleaned and blue painter's tape is applied at one inch intervals around the entire section. A thin coating of DAP Alex Plus acrylic caulk is applied to the spaces between the tape lines and allowed to dry for 24 hours. The caulk strips will hold the wire in place during and after winding.

Here the tape is removed in preparation for winding. The wire transport used in prior projects has been rebuilt using wood instead of plastic parts for weight reduction. The sheave on the headstock has also been replaced with a wooden disk. 

This is the test setup for the new drive. The bulky old pulley fixture had no speed control and is replaced by the Harbor Freight variable speed polisher , HF item number 60626. The polishing pad is replaced by a small pulley from a clothes washing machine sized to accommodate the 1/4" drive belt shown here.

The polisher has a speed range pot embedded in the handle
which can be set to any speed the operator likes. 

The drive is attached to carton for easy alignment with the drive sheave. It's own weight is enough to provide medium tension on the drive belt.

A door hinge attaches the drive to the carton. Now the optimum location for the drive is set directly
underneath the wood sheave.

The wind at the half way point. The 3/32" wire bites into the acrylic strips for consistent alignment.

The finished piece is 9 feet tall, sports 500 turns of wire, and is even free standing !

Here's a closeup of the finished coil. 

A homemade wire guide is shown here. The clear plastic tubing has a 1/8" id  and comes from the stem of a bottle of spray cleaner. The yellow base is a shim used to align ceramic parts. 

The two are held together with Harbor Freight Super Glue.

 As the coil form rotates, the wire is drawn through the tubing and the space between the turns, or pitch, is maintained by the edge of the shim rubbing against the previous turn, held in place by the operator's hands.

Sunday, September 2, 2018

The latest version is up and running...

The .045" stainless steel wire version is finished and set up. The new base section keeps the XLY's flowers out of harm's way.

Have an opinion or observation ? Please let me know. Thanks.


Saturday, September 1, 2018

At the Half Way Point

The first half of the project is completed. It took about 5 hours to wind at a surface travel speed of 138 inches per minute. DC resistance is measured at 295 Ohms. The wire is 309 stainless, .045" diameter.

The adhesive used on the original job with this Cantex section is still pliable, and will hold the wire in position. The best tool I've found for pruning the coil is the human fingernail. If you have a better idea, please let me know.

Setup Complete

The new setup includes idle support wheels that float the tube in an X/Y pattern as opposed to the old wheels which simply rotated in one direction. The 6" tube has a tendency to travel in one direction, the the newer idlers minimize the motion.

The brick shown above keeps the main rotation motor stand from moving as coiling progresses. Over three of four hours, the drive will move on it's own enough to require operator intervention if not held in place securely.

The new wire guide is the cartridge from a ballpoint pen. It's ID is .046 - .048 " and it's wall is .024 -.025". It seems to be made of tough material, and it's perfect for closely spaced wire winding. The goal is to stuff 15 turns of wire into 1 inch of coil form. This translates into approximately 1388 feet of wire per half of the dipole antenna using .045" wire.

Tuesday, August 28, 2018

Beginning a New 6 Inch Project, August 2018

The wire from the old vertical dipole antenna is  stripped off, and the 10' Cantex tube section is ready for a new life.

The support brackets have extra height due to the addition of another carton on each end. The tube is now at eye level for the operator, affording better control and inspection of the winding process.

To accommodate the operator, an extension has been added to the plain end of the tube.

We'll be winding close to the end of the tube, and the idler wheel set has always been in the way.

Adding an 18" extension solves this problem.

The photo on the left shows the 18" piece with an internal alignment mandrel placed on a viewing stand. The arbor is 48 inches long, and fits inside both the extension and the tube. It's made of 2 x 6 scrap lumber, cut into three pieces to form a cross. The wooden  assembly is held together by pressure from the extension, and has a sliding fit inside the main tube. For rigidity, the insert should be set at least 2 feet into the main tube. As the main tube rotates, the extension rolls at the same speed and there is no chatter or vibration. Assembly and disassembly are both quick and easy. And the price is right.

Here the extension is attached. The screw that secures the end of the coil wire is close in length to the wall of the tube: about .238".

Friday, June 8, 2018

Connected and Ready to Go !

The finished part is set up in an out-of-the-way corner so as not to be obtrusive. This is the quintessential all-band ham radio antenna for restricted lot use. The simple neighbors' unwelcome curiosity is kept to a minimum by the low profile, and the XYL can still populate the area with her nefarious green things. 

The tooling is removed and a completed dipole antenna is ready for action. Weight is about 70 pounds, so exercise some caution.

With any garage project using junk parts, unwanted variations in alignment and fit up make their way to the finished product. The Lash shims, or "Wedges", shown here are indispensable for correcting and fixing minor things that need adjustment. A bag of 50 pieces is available at The Home Depot for around $9.00. A very good deal considering...


Tuesday, June 5, 2018

Half of the dipole is complete: 53.5" of wind with .062" (1/16") wire. Approximately 742 feet. Measured DC resistance is 58 ohms.

Monday, June 4, 2018

The head stock and drive motor are lined up and ready for winding. That 14" section from the first slide adds the extra length for winding at the tube base. Now we need the rubber hammer for end-to-end alignment.