Al's Blog-o-Sphere

No, no, not those Hams in Space!

I meant Amateur Radio Operators that are Astronauts. Ever since Owen Garriot, W5LFL, flew aboard STS-9 in 1983, there have been a series of Ham Operators aboard the Space Shuttle and the International Space Station. There were also Russian Hams aboard the MIR space station and Hams from a number of countries have been up in space on the various flights.

You may have been aware of this fact, or this might be the first time you have heard of it. It was a publicity coup for Ham Radio and NASA was fully in support of it. In fact, it couldn’t have happened without their support.

Having Ham Radio represented and operated from space is a great publicity tool for NASA. It also could be used as a backup communications system in the event of serious malfunction aboard the spacecraft. I’d hate to see things go that wrong – I’m sure they have other backup systems, so it would have to be the third or fourth or fifth resort – but it really could be used in that capacity.

So this is a good thing, right? A win-win for Hams and NASA alike, right? Well, maybe. Continue Reading…

…since I last posted here.

What have I done since then? Let’s see. The robotics team has built another robot. I got my Director’s number on the Geratol Net. I’ve gotten a month older…

That’s about it.

The robot for 2012 is done and looking good. We had relatively few problems programming it, though not totally problem-free, less than last year. The kids doing our programming are doing a great job and what we have is truly a joint project with us all putting our heads together to come up with working code. We looked good at the Penfield scrimmage a couple of days before the end of the build season. Two days of practice and fine-tuning at the Kenan center after that got things really humming. Continue Reading…

Today I finally got around to working on the 7 Band Portable Dipole I wrote about earlier. I had finished building it, but hadn’t tried it out or even seen if it works.

One thing that delayed me was my MFJ-259B antenna analyzer was in pieces. A couple years ago, I dropped it on the floor. It landed face-down and smashed the tuning knob. In the process, it bent the shaft of the tuning capacitor and made it stick and short out as it turned. I ordered a replacement from MFJ and installed it, but it still had problems. It acted flakey. It turned out, although it looked fine upon inspection, the range switch was also damaged and was working intermittently. It sat on the shelf for a couple of years while I decided what to do with it. The antenna project made up my mind to look at it again.

I was dreading tearing into a multi-position rotary switch. I had visions of parts and wires hanging off every terminal. Fortunately, it was a PC-mount switch and every connection went through the PC board. If I could only get it off the PC board without destroying anything, I could replace it. So I carefully disassembled the ’259 far enough to access the back of the switch. With some care to carefully desolder each pin and a little wiggling, the switch came out. I ordered one from MFJ, along with some of the plastic parts to the push buttons that had also flown off and been lost in the fall. Continue Reading…

Warning: Ham Radio-related content. If that bores you, better steer clear of this post.

I don’t know what inspired me to do it, but I have undertaken the construction of a portable antenna for my Ham Radio operations. Probably just for something to do, or curiosity to see if such a small antenna can really be effective.

I usually use some method of shooting a wire up into tall trees for this type of operation, camping or just operating “Field Style” for fun. I’ve been pretty happy with the fishing-reel-on-a-slingshot method and I built a Pneumatic Launcher that can be very effective at putting a line over even the tallest of trees. I’ve also acquired some telescopic fiberglass masts (fishing poles) that work quite well as supports for vertical wires. But this design caught my eye and I decided to try it and see.

The idea come from a web page that I saw mentioned on the QRP-L email list: VE3GAM. There are commercially-made antennas that are similar, but this looked easy to make. It might be fun to try.

The idea consists of a shortened dipole on a portable mast and tripod that can be disassembled when not in use. The central portion of the antenna is built using a plastic electrical box and some aluminum tubing. Loading coils are made out of plastic PVC conduit and tapped for the various bands. Further tuning from band-to-band is done by varying the length of the ends of the dipole, which are made out of long telescopic whip antennas. Think of rabbit ears or a transistor radio antenna, but longer. Continue Reading…