Category: radio

I recently added the KXAT1 antenna tuner kit to my Elecraft KX1. The antenna tuner allows me to automatically tune up any non-resonant antenna quickly. Construction took one evening. As usual, winding the toroids was perhaps the most tedious part, but "zen-like" while I was doing them (as I heard it put by someone). I did have trouble with the transformer. It can be tricky and I'll warn other kit builders to check out this thread if they have trouble. I also found some pictures from a japanese ham helpful, but I've since lost them. :(

After building and installing the tuner, I purchased 40ft of some "silky" 26AWG wire from TheWireMan as suggested by Elecraft. I cut the wire to give me two lengths. One length is 24ft and the other 16ft. The 24ft length is my radiating element and the 16ft acts as my ground. The tuner quickly finds a nice 1.1-1.0 match and gives me full KX1 power out (~4W). It makes for a very lightweight, field-portable antenna. I can also use my crappie poles to elevate one end if trees are unavailable.

I use a BNC-to-binding post that I purchased at EPO in Houston. While at EPO, I also picked up a small 12V 1.3Ah gel cell battery. The UB-1213 is about 3.8" x 1.7" x 2" and provides adequate power for portable QRP work. If I was going to operate for very long, I may go with a little larger capacity gel cell, but for now this makes a very lightweight and super portable setup that allows me to get one the air quickly.

About two weeks ago I completed construction of my Elecraft KX1 ham radio kit (serial #2182). It wasn't the easiest build I've done, but definitely the most fun. The purchase was funded almost totally by referral bonuses from Dreamhost. When anyone signs up for an account with my referral link I get a kick-back. I had let the bonuses build up over time and eventually had enough to cover the radio, but I digress.

The KX1 is a "trail-friendly", portable CW ham transceiver. There's plenty of other sites that will give you more detailed information about this gem of a radio. I finally got to use mine yesterday for more than a couple of minutes and I must say I totally love it. The receiver is great, the noise floor is low, the filters are tight, and the features are really packed into this tiny radio.

My antenna was a random wire made from speaker wire with one end elevated to 20' using a BnM Black Widow 20' Crappie Pole purchased at Bass Pro Shop in Shreveport, LA. The antenna sloped down to my BLTPlus antenna tuner which tuned the random wire without any problem. I had the tuner hooked into the KX1 with a short piece of BNC cable.

In short order I was copying stations on 7.030Mhz (40m QRP) and trying to copy the faster stations lower down on the band. I had to tighten up the filters because of the sheer number of signals I was able to pull in. I wasn't able to raise any station due to my diminished transmit power. (I was running off of internal AA batteries because my gel cell hadn't been charged in quite some time.) I was also impatient due to the strong wind, fading daylight and biting insects. I'm going to try again later this week and see if I can't finally capture that elusive QRP contact with this fun little radio.

update: I now have the KXAT1 auto tuner installed.

After almost a year of procrastination I got around to finishing a Rockmite 20 radio kit. The Rockmite is a single-frequency crystal-controlled ("rock-bound") low-power CW HF radio. Say that 10 times fast!

I bought the kit sometime last year and just never finished building it. I had all of the components soldered in, but I never mounted the board in any enclosure. W5USJ, Chuck, Don, K5DW, gave me a metal enclosure during a North East Texas QRP Club meeting. It wasn't until last Friday that did anything with it. I knew the Rockmite needed a home, and here was a nice case for it. I drilled some holes in the cabinet, more or less eyeballing it. They're not perfectly aligned, but pretty close. So now the little radio is mounted, all of the connectors are soldered in and the radio is functional.

It only puts out about ½W at 14.060MHz, on the 20m amateur radio band, but because I mostly operate during the afternoons, 20m is my favorite band for now. I may need to boost myself up to a "full gallon" QRP and get a 5W amplifier like the one Chuck designed, which I might get from QRPme.

Also on my "to do" list, is to add a PicoKeyer chip to the radio which greatly adds to the experience of using it.

update: I got the PicoKeyer chip installed this afternoon. I love the features it provides. The Memory Keyer is vital for QRP work and the hands-free "Tune" feature is great for field-portable antennas. Most of the other features I don't use, but I still think the chip should be incorporated into the original design.

The University of Tennessee Amateur Radio Club (UTARC) has launched their latest balloon "The Spirit of Knoxville IV". It took flight late last night on its voyage across the Atlantic Ocean, into Europe, via the swift moving winds of the jet stream.

The team put a computer and GPS on board to transmit the balloon's location and altitude via ham radio. The data stream is sent out via RTTY and CW at ~10.146 MHz. The data is displayed in rather raw format here and in a more presentable flash-based "dashboard" which features a Google Maps fix on the balloon's last reported location.

Quite a few people are monitoring the balloon so the site is a bit slow to load, but to track the little autonomous balloon is pretty neat. Right now, as I write this, it's zipping along at 111mph @ almost 40,000ft out over the Atlantic.

update: The balloon fell short of its European goal. The payload splashed down about 2:00pm CST, 425 miles southwest of County Cork, Ireland. The balloon began losing altitude the night before and never full recoverd. The decent was partly caused by the loss of sunlight heating the gas in the balloon and/or icing on the surface of the balloon. "Grams will make/break you in this business," one UTARC member said. The balloon's exact location was unkown as radio contact was lost at about 1:51pm CST. Better luck next time guys!

When I bought my new house in April, one of the most annoying things I discovered was that I got virtually zero cell service inside the house. The house is down in a valley and thus has no good line-of-sight to any cell towers. Inside the house I'd get 0-1 bar, and outside on the front lawn I'd occasionally get 2.

To try and remedy this situation, I had two choices: get a landline (with yet another phone number and at least $20/mo) or I could go with a "smarter" solution and get a cell repeater/booster. I found this gem after doing some research online: the YX510 dual-band cell repeater.

So for just over $300 I got this fairly large box containing an 18" external antenna, 35' of high-grade coax cable, and a chunky little box for inside with a little 6" antenna.

I went up on the roof of the house and found that I got 4 bars near the back of the house. So I mounted the external antenna at the top of an 8' 2x4 that I strapped to the side of the house. Then I ran the provided coax around the house into the attic, where I mounted the interior box.

I should note that I took care to put as many physical barriers as possible between the interior and exterior antennas, to prevent feedback loops. In my case, I was able to get 2 sets of shingles and 3 walls in between the antennas.

Finally, I found a good place to plug in the provided wall-wart, then spliced in an extension into the power cable (the provided one was only 4' long). Then I plugged the base unit in, and voila! I now get 4-5 bars all over the house. No more dropped calls, no more "are you there?" when talking to somebody. And I don't need to get a landline.

Highly recommended to anybody that is in a similar situation (bad cell service somewhere but with an easily accessible location nearby with good cell service).

edit: Here are pics of the setup.