Fellow YouTuber, 2E0UKH told me about a 2 element dual-band beam he built. I ran with the idea and made my own, out of arrow shafts, with an additional element. The results? Pretty dang impressive.
2E0UKH YouTube Channel: https://www.youtube.com/user/ukgadget2
MMANA GAL file: https://drive.google.com/file/d/1IQ8l_cLdpa7m4fzYdZe1jQMwLSZQOqi1/view?usp=sharing
Antenna Photos – SWR and Patterns: https://photos.app.goo.gl/GAKAw9uykCkPEijr7
Element Lengths and Positions:
– Driven element
– Position: 0"
– Element Length: 20.17" (ea.)
– Director #1
– Position: 3.78"
– Element Length: 19.05" (ea)
– Director #2
– Position: 13.26"
– Element Length: 18.36" (ea)
Arrow Shafts: https://amzn.to/3oDgpuM
– Note: you can likely find them a little cheaper on AliExpress.com
Threaded Inserts: https://amzn.to/37UQhWm
Arrow Connector: https://amzn.to/3oFrTOA
– Note: you can also just use a threaded rod and a jamb nut or some LocTite to secure it
Nylon Threaded Rod: https://www.mcmaster.com/nav/enter.asp?partnum=98831A330
Aluminum Threaded Rod: https://www.mcmaster.com/nav/enter.asp?partnum=93225A675
… more durable alternative
Stainless Steel Threaded Rod: https://www.mcmaster.com/nav/enter.asp?partnum=95412A882
Nylon Spacers: https://www.mcmaster.com/nav/enter.asp?partnum=94639A534
Aluminum Hex Nut: https://www.mcmaster.com/nav/enter.asp?partnum=93181A009
Key Build Tips:
– Use a drill press. Hand-drilling will not result in straight enough holes.
– Remove the anodized coating from the inside of the arrow shaft before crimping in the inserts. The coating is non-conductive.
– Apply dielectric grease to the outer part of the threaded insert to prevent corrosion.
– If you over-crimp the inserts, you’ll have to re-drill the clearance hole portion and re-tap the threads.
– Be careful installing threaded aluminum rods, as the threads can be easily damaged.
Have fun building, and good luck!
K6ARK Portable Radio shirts for sale (thanks Jason!): https://grapevineamateurradio.com/products/k6ark-portable-radio-t-shirt-special-order