Operating Notes

February 6, 2007 by 2 Comments

Here are a couple of items too short for an entry of their own:

RF in the Shack
I’ve been operating the random wire antenna at only 30W because I was afraid of RF in the shack. After all, the tuner is only about four fee from the radio, and the antenna starts at the back end of the tuner.

Up till now, I hadn’t really seen any evidence of RF in the shack. Yesterday, though, I was calling CQ using the radio’s memory keyer, and while the radio was calling CQ, I was trying to do something on the computer. As I tried to mouse around using the touch pad, the mouse just jumped all over the place. So, there is some RF in the shack after all.

QRP Net on EchoLink
On Sunday evenings, at 9 pm Eastern Time, the EchoLink QRP net convenes. I’ve checked in the last couple of sessions. They chat about all manner of ham radio topics, not just QRP. Check it out, especially if you’re a QRP op.

Filed Under: antennas, Everything Else, Operating, QRP

A Review of the DC40

January 14, 2007 by Leave a Comment

I mentioned earlier that I have purchased the DC40 QRP rig from QRPKits.Com. Well, recently on the qrp-l mailing list, Dave W7AQK reviewed this kit:

I’m fortunate enough to have plenty of QRP rigs to play with. Recently
added a 4 band board to my K1, and now that rig is fun again. But I was
pretty intrigued with the DC40 kit that Doug Hendricks has added to his QRP
Kits, Inc. line. It’s a KD1JV design, so you know it has to work!

Anyway, I needed a project, and Doug filled the void. The kit arrived
Thursday, and it was completed this afternoon. It’s another Steve Weber
masterpiece–simple but very effective. Crystal controlled on 7040, but
that frequency is jumping tonight. Worked K6RO on the first try. That’s
not DX, but he didn’t need any repeats, so guess I’m stirring up a little
ether anyway.

This is a relatively simple kit. Only 3 toroids to wind, and they are
pretty simple. Parts count is actually pretty high, which means you get
quite a bit for what it costs. There is a 15 page manual that goes with the
kit, and construction is in steps with test points to make sure you haven’t
missed something crucial. There are a few errata items, so be sure and
check the www.qrpkits.com website for updates.

The RX has good sensitivity, and earlier I was hearing lots of east coast
guys with good signals. The TX is just under 1 watt–mine registered 800 mw
using my W2 wattmeter. In half way decent conditions you can do a lot with
this little rig.

A keyer is built into the rig, and keying speed is controlled via paddle
input. The keying itself is pretty swift–QSK swift. It also has a tune
function, so you can verify output or run it through a tuner if you need to.

I’m impressed, and for the money it’s a hoot to play with. If you haven’t
built anything for awhile, or want something to stick in your shirt pocket
that really works, give it a look.

In a second e-mail, he noted that the manual contains a couple of errors:

  1. C6 is listed in the parts inventory O.K., but in the construction info it is listed as C16. The real C16 is a couple of lines further down.
  2. Diode D9 is listed as a 1N5718. It’s actually a 1N5817.
  3. The power connection points are actually marked “+V” and “GND” on the board, not “+P” and “G”.
  4. After you finish Group 3, and when you do the test in tune mode, it’s the Dash paddle you hit to put the rig into tune, not the Dot paddle.
  5. I believe some of the pin numbers on U1a and U1b are marked wrong on the schematic. Won’t affect construction, but would be a puzzle if you were troubleshooting. This is being corrected

    6. .

Watch Doug’s website, www.qrpkits.com for updates.

Filed Under: Building/Homebrew, QRP

Yet More Kits

October 20, 2006 by Leave a Comment

A couple of day ago I worked George W2BPI. He had a pretty good signal–he was peaking at S7, and as I expected, his QTH was in upstate New York. What I didn’t expect is that he was running only 500 mW!

He mentioned that the rig he was using was a “DC-40.” That didn’t ring a bell, so I did a quick Google search. (I love having a computer in the shack!)

I quickly found out that the DC-40 is made by Hendricks QRP Kits. Here’s what the website says about the DC-40:

The DC40 Deluxe is a design of well known Hall of Fame designer, Steve Weber, KD1JV. I asked Steve to design an entry level transceiver, that would be simple to build, yet would be capable of making contacts easily.

The DC40 is a moderately complex rig, which yields excellent performance, yet is small enough to fit into an Altoids tin. The receiver features nearly complete immunity to AM SWBC interference and can be run on an AC supply without hum pickup or AM BC interference common to most DC receiver designs. One stage of audio band pass filtering gives the receiver some selectivity. The transmitter puts out a respectable 750 mW of power, with a 12V supply and over 1 watt with 13.8 volts. The transmitter frequency is automatically shifted up about 600 Hz to provide the proper T/R offset. The rig also includes a simple keyer chip.

The rig is priced at $30 plus $4 shipping and handling in the US, $6 S&H DX. The DC40 Deluxe Kit includes all board mounted parts, including a 7.040 MHz crystal. You will need to supply the antenna and power connectors of your choice. The PC Board is double sided plated through, solder masked and silkscreened.

This sounds like a pretty nice little radio for only $30. I’m really tempted to buy one just for kicks.

Hendricks also has some other cool kits. For $60, you can get the “Firefly.” This transceiver has a variable, crystal-controlled oscillator and an SDR receiver. That is to say that you have to connect the rig’s output to a computer with a sound card to use it. All of the “tuning” is done in software.

There’s also the Altoids Long-wire Tuner (ALT). As the name implies, this tuner fits into an Altoids tin and allows you to tune up a long-wire antenna. It even includes an SWR bridge to help you tune it.

These sure look like great kits to me, and I’m going to add QRPKits.Com to my list of kit suppliers.

Filed Under: Building/Homebrew, Gear/Gadgets, QRP

This Weekend on the Radio at KB6NU

August 21, 2006 by Leave a Comment

I had hoped to work the New Jersey QSO Party this weekend. With my 40m dipole, I usually do pretty well in New Jersey, so I had hopes of adding another certificate to my collection.

Unfortunately, there didn’t appear to be much activity. I turned on the rig just after 4 pm and didn’t hear a single CW station around the suggested frequency of 7035 kHz. I tuned up to 7235, and did work a phone station, but he was the only one I heard. A bit later, I did find a couple of CW stations, but overall, it was a bust.

Perhaps the date is the problem. People do go on vacation at this time of year, and on top of that, the SSB portion of the North American QSO Party, was going on as well.

Last night, the Flying Pigs held their monthly Run For The Bacon spring from 9 pm to 11 pm. There were quite a few stations on last night, but conditions were less than optimal. Propagation was pretty good, but the bands were very noisy. I gave up after about 45 minutes. I made ten contacts and scored a total of 224 points.

This morning (OK, it’s not the weekend, but it’s close), a crew of men came to trim the trees in my yard away from the power lines. It’s a good thing I was home. They snagged my antennas a couple of times. I’m afraid that if I hadn’t been home, I’d have found them in a pile on the lawn.

After pointing out the antennas to the crew, they were more careful, though, and I even got them to cut down a small tree that I wanted to get rid of. So, all’s well that ends well.

Filed Under: Contests, Operating, QRP

Lotsa QRP Links

August 2, 2006 by Leave a Comment

Ron WB3AAL has updated the QRP Links page on the Eastern PA QRP Club website. There are links to:

Ron’s looking for more QRP-related sites to add to the page. If you know of any, e-mail him.

Filed Under: antennas, Building/Homebrew, QRP

From the Mouths of Babes…

July 25, 2006 by 1 Comment

Yesterday, ARROW members met for the monthly AMPTeam meeting. I had intended to play around with the crossband repeat function of my IC-207 VHF/UHF transceiver, figuring that crossband repeating could be useful in an emergency. After some manual searching, however, I determined that it doesn’t have that capability! I don’t know how I got the impression that it did. Oh, well.

Instead, I set up the KX-1 as usual. For an antenna, I use the antenna described in the antenna tuner manual, namely a 28-ft driven element and a 16-ft. counterpoise. I actually use three counterpoises–that seems to work much better than just a single one.

In my toolbox, I have a tennis ball and a ball of nylon twine. I poke the twine through the tennis ball, and then throw the ball over a convenient tree branch. The last time I set up out in a park, I snagged the perfect branch on the very first throw. Last night, however, I wasn’t so lucky.

The problem seemed to be that there was just too much friction between the tree bark and the twine. I’d get the ball over the branch easily enough, but the ball was too light to come down far enough to grab it and attach the antenna wire.

All this was quite amusing to the kids who’d come over to watch me. At first they asked what I was doing, and when I explained, they seemed really interested. After a couple of tries, I said to them, “The ball is going over the right tree branch, but it’s not heavy enough to come down the other side.”

I poked around in my toolbox, trying to find something that might make the ball a little heavier, but nothing seemed very easy to use. When I mentioned this to the kids, one of them piped up, “Why don’t you put some rocks in it?” What a perfect solution! They scouted around for some small rocks, which we poked through the hole in the tennis ball, and voila, it was heavy enough now to not only go over the branch, but pull the twine down the other side. I thanked my assistants, who seemed very pleased with themselves.

After untangling the coil of antenna wire and pulling it up into the tree, I got the KX-1 all hooked up and let them listen to some Morse Code. Unfortunately, I forgot to bring along my battery-powered speaker, so we couldn’t all listen to it at the same time. Next time, I’ll remember, though.

I made three quick contacts. The first with K1NUN, yet another card to my collection of QSLs from stations whose callsigns spell words. Next, was KE4RUN, another guy whose call spells a word, but I already have his QSL. Then finally Bob KB3ENU. Although Bob was also QRP, he was peaking at S7 here in Michigan, and we had a fine QSO.

Overall, it was another fine outing for the AMPTeam.

Filed Under: antennas, Mobile/Portable, QRP

More Links

July 18, 2006 by Leave a Comment

The latest in some cool stuff I’ve come across while surfing or digging through my e-mail inbox:

  • Zerobeat.Net’s QRP Links. Zerobeat.Net is the work of Thom K3HRN. This page has lots of links to interesting places, including a tutorial on winding toroids and the searchable archives of the QRP-L mailing list.
  • Make Magazine. The coolest hams are “makers.” Make Magazine was made just for us. If you’re like me, though, you just can’t justify buying yet another magazine, especially one that costs $15/issue. Fortunately, for cheapskates like us, Make magazine puts a lot of its content on its website, and you can access it for free. You can also subscribe to their newsletter, and get lots of interesting stuff in your inbox every week.
  • American Science and Surplus. This is one company that the Make newsletter turned me onto. The website is interesting–I can only imagine what the retail stores (in Chicago and Milwaukee) are like.
Filed Under: Gear/Gadgets, QRP

Yet Another Antenna Idea

June 14, 2006 by 2 Comments

Here’s an interesting idea for a portable 20m antenna from Ed K9EW via the Elecraft mailing list:

As long as you mentioned the inverted vee, I thought I’d offer this to think about. I have been using a 20m center-fed inverted vee with very good results. And here’s the great thing about it… it’s a coil of TV twinlead.

One end of the twinlead is split to form the two arms of the vee (each approximately 17 feet long), and then the remainder of the twinlead becomes the feedline which you can connect directly to your rig. The only constraint is that the feedline portion of the twinlead *must be* an electrical half-wavelength long (about 29 feet, depending on the velocity factor of the twinlead you use) in order to present a 72-ohm impedance to your rig.

It’s small (rolled up), lightweight, and requires one branch about 30 feet off the ground for the vertex. At this height, it’s approaching a half-wavelength above the ground which is great for the radiation pattern. The ends are tied off with small ropes to stakes (or rocks) 30 feet from where the feedline would touch the ground. This will give you a 90 degree angle at the vertex. It’s balanced, so no counterpoise. And it works just like a “home” antenna.

72/73, ed – k9ew

I just knew I’d find a use for that 300-ohm twinlead I bought at the dollar store a couple years ago. :)

Filed Under: antennas, QRP

Dayton 2006: Day One

May 25, 2006 by Leave a Comment

Dayton has lost some of its luster over the years, but it’s still the coolest gathering of amateur radio operators in the world. For the second year in a row, I took some time off so I could be down in Dayton for more than just a single day.

My Dayton started at 5 am Thursday morning, when I pulled out of my driveway, hoping to get to the Fairborn Holiday Inn by 8:30 am. Why so early? Well, that’s when QRP Amateur Radio Club International‘s Four Days in May (FDIM) started.

I drove it in on swell foop and actually made it just in time. I pulled into the parking lot right about 8:15 am, and by the time I got out of my truck, stretched, and got myself registered, it was 8:30 am. How’s that for timing!

The sessions were all really great, and I came away with a lot of good advice and great ideas:

  1. Antennas – the Practical Aspects, Bill Kelsey, N8ET. “Don’t think too much. Throw up some wire and make contacts.”
  2. High-Density Design and the KX-1 Transceiver, Wayne Burdick, N6KR. “Where there’s a will, there’s a way.” (I’m referring, of course to how they shoehorned yet another band into the extremely small box of the KX-1.)
  3. A Regenerative Receiver Primer: A Little History and Some Practical Ideas, George Dobbs G3RJV. “Non multa sed multum” or “Not quantity, but quality.” This was a wonderful talk on how to build regen receivers, and George included a bunch of circuits to play with. I’m going to get my middle school kids to try some of these.
  4. K7QO’s Mark IV Transceiver, Chuck Adams K7QO. I don’t think I came away with any specific idea from this particular session, but certainly a lot of little ones as they relate to homebrewing your own radios.
  5. Making Antennas With Fiberglass Poles, Gary Breed K9AY. “It’s more fun to use these things to make antennas than it is to go fishing with them.”

I’m probably the most geeked about building the regenerative receivers. The circuits are relatively simple, and George showed one project that bore a striking resemblance to the no-solder code practice oscillator that I had the kids build. You first print out the circuit diagram and then paste it to a chunk of wood. Then, you pound in some copper finishing nails at all the circuit nodes and solder the components to them. No circuit board required!

In fact, George advised against doing a printed circuit board for these projects. I can see why. Doing so would add a level of complexity that isn’t really needed. These circuits are simple enough that using copper nails–or perhaps terminal strips–is the way to go. These construction techniques would certainly make experimentation easier.

That evening, there was a “Meet the Authors” gathering, and I got to meet both G3RJV and K9AY. Both are great guys, and it was a very enjoyable time. George was selling a CD with all of the circuits he described in his talk, and I bought that from him for $10. In fact, I was advised to buy one of everything that George was selling, but I only bit on the one item.

In the hallway outside the meeting room, Lloyd K3ESE had set up a small station consisting of his KX-1 and a Buddipole (or some such antenna) just outside the door. They were using the callsign K6JSS, the QRP ARCI club call. For some reason, just as I approached, Lloyd had to step away.

Since none of the other guys were familiar with operating a KX-1, I got pressed into service, and over the next half hour or so, I made about ten contacts with other QRPers operating their QRP rigs in the Holiday Inn and adjoining hotels. That was a blast.

Perhaps the coolest QSO was with AB1AV, who I found out afterwards, was standing right behind me. He was operating a little rig in an Altoid tin feeding a dummy load! We had to quit when he reported that the dummy load was getting too hot to hold on to. :)

Well, that’s all for Day One. Stay tuned for my report on Day Two at Dayton 2006.

Filed Under: Building/Homebrew, CW, QRP

Bring Home the Bacon

April 13, 2006 by 1 Comment

The latest edition of the Flying Pigs QRP Club Bacon Bits Quarterly (BBQ is now online! This issue includes articles on the following topics:

  • phased verticals,
  • tinkering and experimenting, with a great list of resoures,
  • The Great Crystal Swap,
  • and more!
Filed Under: antennas, Building/Homebrew, QRP
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