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A 30 and 40 Meter KX2 Adapter for the Grabil CF-2200 Carbon Fiber (or any other cheap) Whip

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  Executive Summary (don't ya feel important now?) I've been very pleased with the Grabil CF2200 carbon fiber whip for handheld use on the KX2.  The whip is lighter and stiffer than the metal whips I'd been using, and the KX2 readily tuned the CF2200 alone from 10 through 20 meters. But that left me without 30 and 40 meters.  As good as the KX2 tuner is, it refused to match the Grabil on either band. This post describes how I made a prototype 30 and 40 meter adapter that can be left on the CF2200 so that all bands 10 - 40 meters can be tuned by the KX2 tuner.  No reason you can't use this with any cheap extendable whip to build a poor boy's AX-4, but I find that the CF2200 provides field advantages, so I focused on that. The Background I've operated /PM with simple 7 to 8 foot whips on the KX2 for several years now.   Other blog posts here describe how I've built a simple bracket to mount most any kind of a whip on the KX2 without stressing its BNC, and I w...
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My G90 Gets a PROTOTYPE Battery Box!

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  Executive Summary 1) I built a battery box that mounts on the G90 almost like a real manpack 2) The box is built from Kydex and aluminum angle stock. 3) The Kydex plates and the angle stock are riveted together using a cheap Harbor Freight riveting kit. 4) The box mounts to the radio using the rear handle mounting holes. 4) It works great - and looks sorta OK:) A perspective view of the radio and battery box in operation. A close-up of the box. The bottom view. And finally, a side view. A Work In Progress Most of my projects look a bit half fast (sp and sic ), as I typically just want something that works. This works. But it could look better, and I'm sure there many clever improvements that can be made.  I've teed this project up as a thought experiment more than anything because the G90 really needs a battery box. Once modified for generally coverage, the G90 is about the closest thing to a military HF manpack that's affordably out there. So please send along your sugg...
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K9DP BCI Filter - INSIDE THE G90!

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Executive Summary   Oh yeah. This is the ticket. The $20 K9DP QRP broadcast band filter.  Nice price to performance ratio, easy to assemble, and small. If you have a G90 and live 1.5 miles from a 50 KW AM station, you know why you need one.  If you travel with your G90, you may learn why you need one. Turns out, this filter can be easily installed INSIDE the G90, in the form of a new receive jumper.  This permits filtering to be done in the receive path only. No external boxes and cables, and better yet, NOT transmitting through the filter, which happens if you put the filter after the antenna tuner outside the box. In my radio, the install looks like this.  The filter is visible as the heat shrink-encased mass on the right top side of the speaker hole, under the top circuit board. IMPORTANT NOTE 6/1/2025: I've been told the latest model G90s have an additional partition between the two main boards (seen on a Power Pole version) that may complicate installation,...
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The KX-2 Handheld - REV. 2!

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  Executive Summary Still trying not to waste your time.......or am I? If you look elsewhere on the blog, you'll find the earlier version of a KX-2 handheld antenna bracket.  It's been fun, but some people can't work metal, or don't want to leave a bracket on their radio, and, quite frankly, the kit could use a few creature comforts. The REV.2 bracket uses a Gemsproducts Side KX KX-2 radio mounting plate that snaps on the radio. This way, the handheld system can be quickly attached and removed from the radio, without requiring leaving a bracket screwed on to the radio, or any other modifications to the radio. The REV.2 bracket also includes a safety lanyard (guess why) so that there is no need to keep a death grip on the radio while operating. Lighter antennas can be held by adding a Kydex bracket to the mounting plate. To avoid potential stress and large flexing issues, more serious antennas are probably better supported with a metal bracket. I describe both versions b...
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