I've been busy building my Arduino-based memory keyer (based on the work of K3NG) making antennas and doing some SDR work (with GnuRadio) in order to work some satellites.
Last week, I finally scraped the money together to send my FT-102 back to NC4L to be repaired. He thinks it might be an easily-fixed voltage regulator, and we'll soon know for sure.
You may recall that I'm trying to build a compact whole-band antenna for 80 meters, and the simulations I've done show some odd results that I'd like to resolve. To that end I've built a scale model that should work for both 10m and 12m. Unfortunately, the scale model doesn't work and it doesn't work in interesting ways. In particular, it looks like the antenna wire wasn't cut to the right length. I've been wondering what mistake I could have made that would give me the results, but I hadn't been able to come up with anything.
I re-measured and cut new wire and added a ground grid (a four-foot square of chicken wire) and it still doesn't work. The way that it appears to not work is interesting, so I'm recording it. The feedpoint impedance is very small. I was expecting about 100 ohms, and it's less than 20 ohms from 24.682 MHz to around 30.508 MHz and at most of the frequencies in the range, it's less than 10 ohms. I also discovered that I needed to disconnect the resonator from the ground plane to get those numbers. The simulations all connected the resonator to the ground plane.
It's about 3:00 on a Sunday afternoon, and I'm sitting in my shack in a pair of shorts watching dots crawl down a waterfall display. I can feel the aftereffects of the migraine I woke up with and the medication I took to feel almost normal. Sunday is my day for household chores, and I should be doing them, but I'm not. I've got post-convention work I have to do for ApolloCon, the science fiction convention I ran this year while y'all were having fun at Field Day, (lucky bastards,) but I'm not doing that, either. Instead, I'm watching dots crawl down a waterfall display.
I've been offline for a while because of ApolloCon, but I'm back at it. My XYL, KD5SBI, has expressed a desire to do PSK31 on 2-meters FM (and I've confirmed that there is such a thing) and has indicated that she understands the need for an interface box. To that end, she suggested that I purchase the UMI SCI-6 and assemble it, for it is a kit, for her birthday, which is coming up soon.
Last night, Dr. Mal Eiselman and I spent an hour on the phone going over my radio and the news is pretty uniformly bad. There is no loose connection or anything that I'm confident I can fix in the radio. The problem is that the local oscillator board is not working. So, it's back to the good doctor for repair.
The one bright spot is Dr. Eiselman whose efforts to assist me are much appreciated even though they were ultimately unsuccessful. I can definitely recommend NC4L as the guy to fix FT-102's.
ON6DX will be in Curacao from June 28, 2013 to July 7, 2013 as PJ2/ON6DX.
I am attempting to create whole-band antennas for 80m and 160m that will actually fit on my yard. NEC2 says that a particular design will definitely work, but having built a 10/12m scale model of the larger antenna, well, it doesn't work. I'm going to be investigating why. I hope it is because I made a construction error.