Archive for June, 2010

50-MHz Progress

June 14th, 2010

As I mentioned in the previous post, I’ve made some strides toward getting on 6 meters over the weekend.  I assembled the 3-element Yagi last weekend.  It was leaning against a post in our back yard pointing skyward for a few days.  I told Sarah that I was thinking of adding 18,431 more of these antennas so I could compete with the 50-MHz radar at Jicamarca.  She was not amused.  I hadn’t even mentioned anything about megawatts.  Yes, Virginia, the mast in the photo is not square.  The top portion of the mast is a little skewed in the rotor and it’s attached with rusty U-bolts that I’ve never loosened.  I’m still turning the antenna with the TR-2, even though I have a T2X out here now.  I will do that swap eventually.  But, for right now, the TR-2 is doing fine.

In order to start moving the transverter toward its new home in a beautiful rack-mount enclosure that previously housed a 900-MHz digital repeater (not included when I obtained the box, unfortunately), I had to “re-arrange its internal organs”, as a menacing extraterrestrial used to say in Space Quest.  Sarah wonders why I schlep all of this crap from place to place with us.  I’ve had that rack-mount box longer than we’ve been married!  It was just waiting for a chance to serve in my shack.  Anyhow.  You can see the layout above.  Sarah says it looks like a doll house.  Pretty sweet house, if I say so myself.

Here’s another view of the partially-integrated box.  I’m running it off a battery because I don’t have the power supply subsystem installed in the box, yet.  It’s really just a PA and some control circuitry away from operational.  Although, I would like to align the TX side with a spectrum analyzer at some point.

I heard quite a few signals in the ARRL contest over the weekend.  W5ZN comes to mind, as well as a couple of locals like N4QQ, who lives just a stone’s throw away on the other side of the Beltway (aka the wrong side of the tracks).  I suspect that the locals would move the S-meter a little more (like past S9) if I put an IF amplifier in after the RX mixer.  But, I’m not really keen to do that unless I have to.

Schematics will come once I’m finished.  But, nothing about this so far has been rocket science (or brain surgery, as the rocket scientists say).  I’ve just been following the Handbook.

Magic: right place, right time

June 13th, 2010

I put the 3-element 50-MHz Yagi (Cushcraft A50-3S) up yesterday morning with the 6-element 144-MHz Yagi (WA5VJB design) above it—just in time for the ARRL June VHF contest!  The 50-MHz transverter is not yet complete, although I have the RX side done and the TX side makes about 250 mW.  It’s not integrated and I haven’t started building the PA.  Bummer because yesterday was a pretty good Es day from what N3OX told me last night.

With 10 watts from a TS-700S to a 6-element Yagi at 30 feet, there’s not a whole lot you can work on 144 MHz.  Plus, everybody was on 50 MHz, so I could only hear the multi-operator and serious single-operator stations on 144 MHz locally.  Around 21:00 local time, Sarah and I had just returned from a walk.  I had pointed the beams WSW (my best shot from here is SW) and was slowly tuning up and down the band hoping for some tropo enhancement or something…and after a few passes, I heard on 144.210 MHz…

“CQ contest, CQ contest, looking for sporadic-E on two meters, CQ contest, Kilo Five Quebec Echo…”

That’s something alright!  I figured the beam was in approximately the right place and gave him a call.  He came right back and we exchanged grids.  He was there for a few minutes and then disappeared as suddenly as he had appeared.  I know he made at least one other QSO, but he was starting to fade by that point and I couldn’t hear the other side.  Cool!

My logging software calculated the great circle distance as 1037 miles (1669 km) between FM19 (me) and EM31 (him).  Either it was one heck of big meteor or (more likely) one heck of a sporadic-E opening.  Either way, I’m pleased.  Want more of that!

More on Platform Agnostic

June 4th, 2010

Glad to see that someone else aggrees with me, at least from a security standpoint.

This reminds me of a liberal arts professor I got to know as an undergraduate.  I was a bit more idealistic at the time and told him that if he upgraded his Power Mac to OS X, he would be less vulnerable to viruses since it was based on (BSD) UNIX.  “That makes sense, ” he said, “eunichs don’t get viruses.”  Good guy, but weird sometimes.