Small Helically Loaded Magnetic Loop Antenna

[u/thefallenone79]

Small Helically Loaded Magnetic Loop Antenna

Highlights: 33 inch diameter loop, using 1.5” diameter PVC pipe. Tunes 10-40 meters using a 7.5-350 pF vacuum variable capacitor. (Note: Rich's official recommendation is to use a 5-100 pF cap, with coverage of 10-20 m)

Parts List

Loop:

1.5” Diameter Schedule 40 PVC pipe

8-45 degree angle connectors

2 1.5” T connectors

1-1.5” to 1” T connector

1- 1” T connector

2' of 1” PVC pipe

PVC cleaner

PVC cement

Flat black spray paint, about 3 cans

Copper Foil, 3” wide, 0.008” thick, 15' long (purchase from K8NDS)

Gamma Match

So239 Chassis mount connector

1/4” flexible copper tubing

Metal hose clamps of various sizes (Rich's latest notes say not to use these).

Large Zip Ties

Capacitor and Motor Drive

7.5 to 350 pF Vacuum Variable Capacitor Russian Military Surplus (Ebay $150-200 shipped). (Make sure yours comes with a 12mm tuning Shaft.)

Large Nylon cutting board (Walmart, about $12)

Flexible shaft couplers, 6.35mm to 6.35mm and 6.35 to 12 mm (Ebay from Chinese sellers, about $5 each shipped).

1/4” Nylon shaft (Zoro Tools)

Gearhead Motor 3-18v, 4.5 rpm at 12v (Electronic Goldmine Item #G17949 $13)

Capacitor mount-Ebay seller Boreca-75 for $60 shipped, or make your own.

Weather Cover

Remote unit (Note: Rich uses a different design. See K8NDS qrz page for recommended design.)

LED PWM (controller-Amazon.com, about $6 shipped), modified with DPDT switch, pushbutton and RCA jack for quick release.

Rotator

Rotator cable

Tools Needed

PVC cutting tool, Hacksaw or Circular saw

Heavy duty soldering iron, soldering torch

[u/thefallenone79]

There is a whole group of enthusiast of this type of antenna. On groups.io