This ultra-light antenna is a great choice for operators wanting a pocket antenna covering both 20m and 40m without needing a tuner. It is ideal for minimalist QRP setups but can easily handle 100 watts as well.
If you don't plan to operate on 40m you can easily detach the 40m sections and leave them home or in the car. You can also connect unlinked sections using plastic S-biner clips and then switch to ring terminals for linking.
Theory:
This is a simple, resonant 20m dipole with add-on sections for 40m. I used split key rings for links so the antenna can easily and quickly be lengthened/shortened without tools.
20m/40m Linked Dipole
Details of my "nano" 20m/40m linked dipole:
• female BNC connector with screw terminals
• 20m elements = 16 feet of 24 gauge insulated wire
• 40m elements = 15.5 feet of 24 gauge insulated wire
• links = split stainless steel key rings
• line extenders = 10 feet of braided mason line
• weight = 3.5 ounces / 100 grams
Why did I choose 24 gauge wire? Simple. It was scavenged from discarded Christmas lights.
Deployment as Inverted-V:
1. Toss throw line over branch at least 20 feet up.
2. Make loop in coax and secure with velcro tie.
3.
Tie throw line to loop for hoisting.
4. Spread out antenna elements and extenders on ground to prevent tangling.
5. Hoist antenna.
6.
Secure extenders to tent stakes or other objects.
TIP: You can tweek the resonant frequency by raising/lowering the antenna to change the apex angle. Flattening the antenna will lower the resonant frequency slightly. Raising the feedpoint will raise the resonant frequency slightly.
TIP: Don't need ultralight? Make this antenna with 18 gauge wire for more durability. |
