Modifying magnetic mobile antenna mount to accept radials

Modified base and MFJ-1979 whip

In preparation for an upcoming mobile rove to Maine and the Canadian Maritimes, I've finally done something I should have done long ago - modified the magnetic base of my mobile antenna to accept radials.

Previously, whenever activating from the car, I either used no radials at all (10-20m) or connected one radial to the FT-891's rear panel ground lug (when on 30/40m).

But ideally, radials should be at the base of the antenna.

The "mod" simply involved drilling a hole in the plastic base of the antenna. I did this from the bottom of the mount, up through the metal plate to which the coax shield is internally connected.

A 6mm bolt then extends through the hole, allowing me to secure a spade lug to which radials can be attached, along with a Wolf River coil (40m).

Two of them, each a 1/4-wave long on 40m, are now part of the mobile set-up.

Spots into Europe on 40m several hours before my sunset seem to suggest it works well enough, as do the faster autotune times of the tuner.

Of course, the other bands benefit as well from the more substantial RF ground than my small car chassis offers.

Hurricane Idalia passed by from about 4:30-6 this morning. By 9am, patches of blue sky were already showing and I decided to activate a nearby Wildlife Management Area.

Surprisingly, there was no storm-related QRN and the bands were in excellent condition with EU easily worked on both 10 and 12 meters.

The FT-891 is becoming my favorite rig for this type of activity.

At 100 watts, it uses 6AH per hour from

a LiFePO4 battery. Therefore, a 2-hour battery (12AH) provides me with all the time I want for an activation and a log-full of contacts from a wide geographic area.

The autotuner and memory keyer complete the package without it becoming too big or heavy to be portable, whether in the car or on the motorcycle.

100 watts is 8dB better than my KX3's 15-watt output.

For context, think of the work (and expense!) hams go to to improve their antennas by only half that amount.

Barring unforeseen circumstances, I hope to be in Maine for a few days, beginning 12 Sept, then north from there, to cooler, less Florida-y climes:

VE1, VY2 and VE9/AE5X, hopefully.

This morning's 1-1/2 hour activation results:

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