HAM Radio Loading Coil

This is my prototype version of a DIY Loading Coil for HAM Radio. (UNTESTED)

It is a glue together design for the 3 main coil parts (bottom_coil, main_coil, and top_coil). 

The coil caps, and radial ring can be screwed on and off via the printed threads. so you can assemble/disassemble as necessary.

The coil can be extended by printing two main_coils and an extension_sleeve.

Requires a SO-239 bulkhead/surface connector, wires, nuts, bolts, washers, alligator clips, solder, etc. Once it has been tested, I will update with a BOM.

Threads for the two caps are 3/8x24 so you can screw a whip of your choice to the top and connect it how you see fit to the coil.

The radial ring has space for up to 12 radials.

Bottom_coil_cap-No-Threads has the 3/8x24 threads removed. Can be used as a base in conjunction with the spike_half. Print two spike halfs laying down, and glue them onto the no-thread cap. So you can plant the coil directly in the ground.

I am currently in the testing phase, and have not field tested the unit yet. Do so at your own risk.

Note design was completed with imperial units, adjust accordingly

Update 1/27/2022: 

• Replaced top_coil with one that has the proper threads to match the top_coil_cap. 
• Added a second bottom_coil_cap-No_Threads which has the 3/8x24 threads removed.
• Added a Spike_Half.

Update 3/9/2022:

• Added additional top_coil_bolted which was modified to accept M5 bolts instead of glueing to the main_coil.
• Added additional main_coil_bolted which was modified to accept M5 bolts instead of glueing to the main_coil. Note: The main_coil_bolted is not able to be used in a double stack variation with the extension_sleeve.
• Added bottom_coil_flush with the four holes for the SO-239 connector removed so you can drill your own to match your specific hardware. User experience noted there were some variations in hole spacing.