I remember that as well. Well over $100 for even a moderately sized
coil. That's why I came up with the do-it-yourself 3D printed concept
that I posted here a few days ago. I can make exactly the coil I want
(length, diameter, wire size, number of turns) for pennies within the
same day. In case anyone missed it, here's the version that has a very
slight taper. I also have a video that shows how to make a coil with
uniform diameter, but to be honest I can't really think of a situation
where that would be needed ... no coil we make is likely to be EXACTLY
the inductance we calculate so we're going to be trimming or tuning anyway.
https://youtu.be/qAgF9Mzr8XM
The approach uses OpenSCAD (a free and easy to use parametric modeling
application) to create the .stl file for the coil form, and the OpenSCAD
code itself (which allows you to set the specific parameters for your
particular coil) is available as a free download from:
https://www.printables.com/model/371698-air-wound-coil-form
3D printers are great for ham radio stuff like this. I've always
thought that every ham radio club should have one for the needs of their
members. Even a $300 (or less) printer would handle most projects and
the filament is pretty inexpensive. I have other videos on YouTube
showing how easy it is to make VHF and UHF antennas for satellites (ham
radio, weather maps, INMARSAT marine and aviation communications, etc)
using 3D printed parts, for example.
73,
Dave AB7E
On 8/4/2025 3:03 AM, Rob Atkinson wrote:
The last time I looked into buying from B&W which was a few years ago,
I was stunned by their prices on new coil stock. They wanted hundreds
of dollars for an airdux wire coil that might have been 6 to 12 inches
long, 4 inches diameter and maybe six TPI, IOW your typical antenna
coil.
73
Rob
K5UJ
_______________________________________________
_______________________________________________
TowerTalk mailing list
TowerTalk@contesting.com
http://lists.contesting.com/mailman/listinfo/towertalk
_______________________________________________
_______________________________________________
TowerTalk mailing list
TowerTalk@contesting.com
http://lists.contesting.com/mailman/listinfo/towertalk
|