Repairing a Steppir Biggir Vertical – part 2 – rebuilding the 80 meter coil assembly

UPDATE April 2021 I now believe that I know exactly what has caused these failures. It is NOT the manufacturer’s fault ! Jump to the ‘solution’ here The first 6 articles in this series will remain here as an example of troubleshooting, analysis, and repair of this antenna.

This is part two of the multi-part adventure. You may desire to start here with part one.

I contacted Steppir, and although they were quite inconvenienced by government demands for the Wuhan Flu, they still communicated rather quickly by email. I decided to purchase a new switching PCB and a new switch rotor assembly (with new contacts installed.) The price they asked was much less than I expected.

I also asked for all new brass screws so that I would not have to unsolder them.

New PCB for Steppir 80 meter coil kit and the old.
You can see the brass screws that make cable connecting terminals M1-M4, as well as the Ground terminal along the bottom edge.

Checking through the Steppir website I saw that they now have a fiberglass plate for the “high wind kit (HWK)” Now I had never installed the HWK because they clearly state that the HWK should not be installed on the Biggir if you are using the 80m coil AND an amplifier.

Now let’s get out the BIG soldering copper and the solder sucker and resume removing good components.

Steppir Biggir 80m coil kit 4:1 transformer.
The stepper motor that turns the coil-tap selector has been removed. It was mounted through the large hole and with 4 screws.

The coil before removal and cleaning.

The yellow turns-spacer on the coil reminds me of “weed whacker” string.
The new brass screws are soldered to the new PCB.

When re-assembling, pay attention to the order of lockwasher, brass nut, washer with integral rubber washer. Do not install those parts until the brass screws have cooled from soldering.

In this photograph, we have installed the SO-239 connector, the 4:1 transformer (bottom side) the coil (after thorough cleaning), the stepper motor, and new rotor.

Note to the left side of this image (under the word SteppIR) an aluminum tubular spacer. This is held in place with a screw and it limits how far the switch rotor can rotate. Different versions of the 80m coil assembly use different methods of stopping the rotor.

Don’t forget the rubber gasket that goes over the SO-239.

So we have rebuilt the 80m coil accessory assembly. Re-install the PCB / coil assembly into the ABS housing, hook up the control cable, and get back on the air 🙂

Maybe not. This adventure will continue in part 3, or, click here if you missed part 1.

You may also like...