[Elecraft] AX1 may add 40 meter coverage with "AXE1" extender

[Wayne Burdick]

Hi all,

Sometimes the bands normally covered by the AX1 just aren't open (20/17/15 meters), yet 40 meters has all sorts of activity. Like tonight, at my QTH. 40 m is also a great local/emergency band, with many active regional nets.

For such times, we may offer an extender for the AX1 that moves the 20 meter resonance down to 40 meters. 

A significant amount of additional inductance is required. The ATU built into the KX2 or KX3 provides any needed fine-tuning to efficiently cover the entire band, despite the unavoidably narrow-band nature of a short whip.

I whipped up a prototype of the hypothetical "AXE1" this afternoon and had excellent on-air results. Tests were done in my back yard, featuring hard-packed soil and brown unwatered grass...in keeping with our legendary drought. With one call each I bagged British Columbia and Colorado. Both stations were peaking S-9, and both gave me reports in the S-5 range. 

This brings up an important caveat: a short whip is not the optimal antenna on 40 meters by any stretch, so calling strong stations is a good strategy. They could be strong due to propagation, good antennas, or high power, and two out of these three aid both ends of the QSO.

The extender would be about 6" long and 1/2" in diameter. (Even a small amount of added length helps on 40 meters.) It threads into place between the AX1's whip and base, and adds just 1.8 ounces of weight, still consistent with hand-held use of the KX2.

Equally important, for those of us who travel light, the extender -- plus a counterpoise wire for 40 m -- fits comfortably into our smallest bag, the CS40, along with the AX1 and an AXB1 whip bipod.

(In answer to the inevitable question: it *might* also work on 30 meters in a pinch, with an ATU, but efficiency would be lower.)

If you'd be interested in AX1 use on 40 meters, please email me directly. I won't necessarily be able to respond, but this will help us gauge interest. We'll keep a list for possible early announcement.

73,
Wayne
N6KR