The 80/160 and 40/80/160 multi-banding L/FCP projects can use a three inch length of Ameritron's #404-0024 coil stock (3 inch diameter, 4 turns per inch, #10 AWG). This was used in their AL82, AL1200 and AL1500 output pi networks. Once treated per (A) it has a near infinite shelf life. To keep from ruining coil stock during cutting, bending and installation, very easy to do, important information points apply. Please read A, B and C below:
(A) The coil stock itself is a bit fragile as manufactured. For this strengthening task only use Krazy Glue™ or an exact equivalent very thin consistency cyanoacrylate glue. Do not use a "regular", "gel" or "thick" glue. It will not soak into the bubble spaces.
Put a tiny drop of glue on both sides of the wire at all points where the wire is melted into the support rods. The very thin glue will soak into the tiny air bubble spaces where the wire embeds the plastic.
Start on an 11 inch coil with a brand-new, unopened small bottle of Krazy Glue. You will use most of the bottle placing 178 drops for the 11 inches. Previously opened Krazy Glue does not store well, suffering loss of ingredients to the air with air pressure changes, even with a tightly closed cap. When you have finished the coil, unless you have something immediate to do with the rest of the glue, throw away the bottle.
Allow the full 24 hours for full curing before handling or cutting the coil into smaller pieces. When you have done this, the coil will have a distinct rigid solid "feel" to it.
(B) It is highly recommended that you cut the coil wire and plastic support rods with a Dremel tool or equivalent. Wire cutters create a large longitudinal pressure on the wire or plastic support rods during the cutting which can shatter the plastic or break the wire-plastic bond. Cutters work by pushing into the wire with a wedge-shaped cutting edge which tries to push the wire apart while the coil structure is trying to hold the wire together. A Dremel cuts by removing material.
When you are cutting a piece of the coil stock to use, leave extra length for forming mounting wires. To do this, leave an extra entire ¼ turn for connection on either end. Do not attempt to use the short ⅛ turn piece for connection. For three inches count 12 full turns plus two additional full ¼ turn sections, a total of 50 ¼ turn sections. In the middle of the 51st ¼ turn section cut the wire with the Dremel tool. Keep the angle of the cutting disk to the wire very small, almost parallel to the wire, to keep from scoring the adjacent turns. You can clean up the coil after you separate the 12 turn section.
Cut the wire before you cut the clear support rods. Otherwise you risk separating the wire from the support rods, which you will find amazingly difficult to repair.
Before cutting the support rods, twice carefully recount the ¼ turns, and twice carefully verify the cutting points. Mark the verified cutting points with a sharp tipped marker. It is very easy to get the cutting points mixed up if they are not marked.
Once the coil section has been separated, free the outside ends of the ¼ turn end wires from the support rods, cutting with the Dremel tool right next to the outer wire. You can then clean up the outer end of the ¼ turn worth of end wire with the Dremel tool.
Important: When forming the bends for the connecting ends of the coil, do not use the clear support rods as the rigid clamp for bending the wire. Use an end tip of a bench vise or vise-grip pliers to solidly grab the ¼ turn end wire right next to the clear support rod. Then make your bends, cuts, etc, with the vise protecting the fragile wire/support rod junction from any twisting or bending moment. Later on, if adjusting the mounting leads, always protect the wire/support rod junction.
(C) Until you have performed (A) on the coil stock, do not store or use this coil stock anywhere the air can be damp (including outdoors in an enclosure). Where the wire melts into the support rods, if the tiny bubbles get filled with water, carbon arc paths can develop under high power. The Krazy Glue fills the pockets where the tiny bubbles touch the wire. For that reason it is a good idea to do (A) when you first get the coil stock.