6 to 80 Meter Loading Coil – Two Rivers Amateur Radio Group

Adjustable Coil for Portable HF Ham Radio

Photograph of loading coil. White PVC form wrapped with copper wire with a wide clamp and a wire lead. — W5OLA 6m to 80m Loading Coil

We are excited to announce the launch of our 6 to 80 meter variable loading coil for portable HF ham radio operation. This loading coil is perfect for a day on the air from your favorite park, a weekend camping, or even hiking. Just add your favorite 17′ whip antenna, a base and some radials, and you can work the world.

Our coil is a performer! Featuring copper wire and an easy to adjust sliding clamp, this coil provides a wide bandwidth across every amateur radio band from 6 meters to 80 meters.

Check out these SWR measurements

Image showing SWR curve for 10 meters. SWR is below 1.5 to 1 across the entire 10 meter band.

Image showing SWR for 15 meter band. SWR is below 1.2 across the entire 15 meter band.

Image showing SWR for the 40 meter band. SWR is below 1.5 across the entire 40 meter band and lowest at 1.07.

Image showing SWR for the 80 meter band. SWR is lowest at 1.68 to 1.

All of the above measurements were with a 17′ whip and 15 radials with a length of 6.5 feet. The 80 meter measurement was taken with just 10 radials of 6.5 feet.

For 20 meters to 6 meters, just leave the tap on the coil at the top of the coil, and adjust the length of the whip. For 40 meters, fully extend the whip and adjust the tap about a 1/4 of the way down the coil. For 80 meters, you’ll lower the clamp about 3/4 of the way down the coil. Connect your antenna analyzer and find the sweet spot, and have fun!

We conducted our testing with a set of 15 radials that were 6.5 feet in length. For 80 meters, we found that the best SWR was achieved with only 10 of the radials connected.

This coil is custom made in the USA, right here in the Arkansas River Valley by volunteers from the Two Rivers Amateur Radio Group. Each coil is machined to ensure consistency in build quality and on-air performance of your coil.

Product Photos

Photograph of loading coil. A PVC form is wrapped with copper wire and an easy to use clamp with a wire connecting to the bottom of the coil.

Photograph of the top of the coil, showing the 3/8" x 24 female thread for the antenna whip.

Specifications

Power rating: SSB: 100 watts / CW: 75 watts / Digital: 50 watts
Length: 14.5″ (36.8 cm)
Width: 2.75″ (7 cm)
Weight: 1 lb 9.5 oz (0.72 kg)
Mount: Bottom stud is 3/8″ x 24 to fit a standard mirror mount or similar antenna mount. Top is tapped with 3/8″ x 24 thread to accept a standard antenna whip. If you have a whip with a 10mm stud, check out our 10mm to 3/8×24 adapter.

Price: $50.00 + shipping

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