I’m still working on the second part of the 6-meter Yagi video series, so I decided to show an example of trans-Pacific AM broadcast band reception using the RTL-SDR based AM BCB receiver detailed in Episode 006. This was from an SDR recording on the morning of September 21st, 2016 and was a pretty good session. Unfortunately, the audio was rather uneven because I was trying for the first time to “internally” record my laptop screen instead of shooting with the video camera. That part worked great, but the audio didn’t go quite as well. Still, this gives a nice flavor for what I have been able to from Arizona with the RTL-SDR based AM BCB receiver, and the Conti Superloop antenna featured in earlier videos.
I’ve been spending a lot of time coming up with a good way of motorizing the tuning shaft of the vacuum variable capacitor, and make the whole assembly modular so I can move it from one loop antenna to another to optimize a particular band. I only ended up using one antenna during the 12-hour NA QSO Party on Saturday, but it generally went pretty well. Continue reading
Forgot to put this up earlier, but Episode 006 of my Arizona Signal Watcher video blog is up. This one is a brief “tour” of the RTL-SDR based receiver that I use for AM broadcast band DXing. If you think you need to spend several hundred dollars to do well on the AM BCB, you might want to have a look. A $20 RTL-SDR, plus a $45 upconverter, and maybe some amplification (depending on your antenna), and you may do as well as possible considering the crowding on the band and other issues.
Now that I’ve been working on ham radio antennas, I have a couple of projects for the video blog. The first one is a 6-meter 4-element Yagi. It is designed to be semi-portable, and for me this is particularly important because it’s not practical for me to leave up an antenna for any significant length of time. Perhaps impudently, I am posting this introduction and design video before I actually have the antenna on the air! However, I have tested the antenna itself (sans 1:1 balun) with a VNA and it seems to behave more or less as expected.
I spend a lot of time talking about various design parameters and the actual modeling procedure, so this may seem a little dry if you’ve done this before. But, I try to keep my speech pace relatively slow on these videos, so there’s always the 1.25x and 1.5x speed options on YouTube. Part II will detail the construction process, and Part III will show testing and hopefully actual on-air performance.
With such low solar activity, 10 meters behaves more like a VHF band in that you have to chase specific openings from sporadic-E, TEP, etc. In principle, I like that better than having “guaranteed” contacts at lower frequencies. But, I was also operating at 5 watts QRP, making it doubly challenging. Continue reading
Okay, now for the more extended story concerning the beginning of my true amateur radio operating “career”. Continue reading
I had my 10-foot magnetic loop antenna ready to go for this weekend’s ARRL SSB contest, but realizing that it would only work one band (20 meters) for that contest, at the last minute I decided to build a new loop to finally go on the air as K7HKR. I used this on-line calculator to figure out something optimized for both the 20- and 40-meter bands with the high-voltage variable capacitor I have on hand. This ended up being a 15-foot circumference loop made out of 1/4″ copper coil pipe, which is much easier to bend than the 1/2″ pipe I used for the 10-foot loop. Continue reading