QRP Operating Notes

Last weekend, our family had its annual get-together “up north,” as we say here in Michigan, at some cabins on Elk Lake. As I have for the last three years, I took my Elecraft KX-1 and did some operating.

This year, I had a lot more success than in years past. I attribute that to my antenna. The first two years, I used a 28-ft. random wire with a counterpoise. This is the antenna recommended in the KXAT1 antenna tuner manual. 28 feet is not a half wave on either 40m or 20m and, therefore, does not present a high impedance to the tuner at those frequencies. That antenna did tune up, but it wasn’t a very good performer.

This year, I used the 66-ft. doublet that I built last summer at an AMP Team meeting. Every time I’ve used it I’ve gotten good results. This year was no exception. In fact, I almost worked my first DX on 40m. One night, I heard EI9JF calling CQ. He had a strong signal, so I thought I had a good shot at working him. He heard me, but couldn’t quite make out my call, though, so I can’t claim a QSO.

One of the contacts I made was with W9ZN in Chicago. He was running a kW, while my little KX1 was putting out only 3W. Even so, he gave me a 579 signal report. He, of course, was 599+ at my QTH. Just goes to show you that you don’t have to run big power to make contacts.

Another notable contact was with N8UN in East Jordan, MI. East Jordan is about 20 miles away from where I was, as the crow flies, yet he gave me a 599 report. That got me to speculating about the propagation between our two locations. It seems to me that 20 miles away would be too far for a ground wave, but it also seems unlikely that we’d have been bouncing a near vertical signal off the ionosphere. I guess the latter is more plausible than the former, though. If you have any thoughts about this, please leave a comment.

Dayton 2008!

Well, I got back from three days at the Dayton Hamvention last night, and as usual, it was a real blast.

As I did two years ago, I started this year’s event with QRP-Amateur Radio Club International‘s Four Days in May seminars. This series of seminars lasts from 8:30 until about 4:00 pm and are just chock full of information and inspiration.

This year, the three presentations that really inspired me included:

  • “Life is Too Short for QR” by George Dobbs, G3RJV,
  • “QRP Contesting” by Ward Silver, N0AX, and
  • “Phasing Techniques in the Digital Age” by Phil Harman, VK6APH.

As you might expect, Rev. Dobbs’ talk was more inspirational than informational (please forgive the made-up word there). The thesis was that ham radio is a hobby, and we should indulge in it as such. That being the case, QRP is the perfect pursuit for those of us who treat it as a pastime.

It wasn’t all philosophy, though. Intertwined with the inspiration, George managed to sneak in a bunch of radio theory and simple circuits.

Just Do It
I do a bit of contesting—even a QRP contest now and then—so much of the material in Ward Silver’s talk was not news to me, but even so, it was both inspirational and informational. While he mostly exhorted the boys to just get out there and do it, he also included some pearls of wisdom.

One of the things he said that got me thinking was his explanation of how to use the two VFOs in your radio (assuming you’re using a radio with two VFOs) to maximize your “search and pounce” efforts. Basically, the technique goes something like this:

  1. Find a station calling CQ.
  2. Program your B VFO with that frequency.
  3. Find another station calling CQ.
  4. Switch back and forth between them until one of them answers your call.

This is a simple technique that ought to increase your score in the next big contest.

Phasing Techniques
Put this presentation squarely in the informational category. Phil explained phasing techniques and how software-defined radios use them so simply that even I understand it now.

Also, chalk this up as inspirational, though. While discussing the talk the next day with one of my colleagues who has been entranced by the SoftRock, we started considering how we might build some hardware of our own up and playing with it. We even went out an bought some cheap mixers from the Mini-Circuits booth to play around with.

Well, there’s just a quick take on my first eight hours in Dayton this year. More to come on the rest of the experience.

Tx Topper Provides Pop for QRP Ops

I’ve written before about how it would be nice if QRP ops had a little more ooomph from time to time. I was thinking that 20 or 30 W would be a good figure to shoot for. That’s a little over 6 dB for a 5 W transmitter.

For even lower-power rigs, such as the DC40A that output 1 W, there is the Tx Topper. This amp, designed by Chuck, W5USJ, and Jim, K8IQY, provides about 5 W output.

Chuck and Jim have provided a nice set of documentation for this project. I may just have to build it once I’ve completed the DC40A kit I’m working on.

Wind-Powered Generator for QRP?

Brad, AA1IP, writes to the Flying Pigs QRP mailing list:

The November 2007 issue of Popular Mechanics magazine describes “Breakthrough Awards”, one of
which discusses an interesting power source. Picture a taut membrane clamped at both ends, with a small button magnet affixed near each end. When the wind blows, the membrane vibrates, moving the magnets into and out of two pickup coils. The circuitry isn’t
described, but I imagine that a couple of low forward-voltage-drop diodes steer the coils’ outputs to rechargeable batteries.

Here’s a descriptive video. I could envision using one or more of these in a hilltop location.

The First Solid-State QRP Rig

The 12/26/07 of the ARRL Contest Rate Sheet had the following item:

Next time you open up your radio, consider that 55 years ago George Rose K2AH, made the first solid-state amateur transmission with a single-transistor homebrew rig. It used an RCA point-contact germanium transistor. Rose measured an input power of 24 mW and estimated the radiated power at somewhere around 50 uW. He made a contact with 25-mile distant W2UK and with W2KNI and W2DPB. (Thanks, Stew W5FYI)

On the qrp-l mailing list, Jason, NT7S, pointed us to AA1TJ’s 80m 1950′s “Retro” QRP Transmitter Web page. This page describes an 80m QRP rig bulit with a couple of 2N35 germanium transistors.

AA1TJ says, “I’m curious to know not only, “How low can I go?” but also, ‘How bad can the active components be?’ and still communicate.” The 2N35 was marketed as an audio transistor and the spec sheet claimed a maximum usable frequency of about 1 MHz. Even so, AA1TJ did manage to make the thing oscillate on 80m and make a few contacts!

G3VGR’s IC-735 QRP Mod

The IC-735 is set at the factory to output about 10 W when the output control is at the lowest setting. It’s not difficult, though, to change this setting. All that’s required is to adjust a pot on the main board. Dave, G3VGR, has a very nice page with clearly written instructions and a photo that makes this adjustment a snap.

Thanks, Dave!

A New Antenna for My KX-1

Since I’ve owned my KX-1, the only two antennas that I’ve ever connected to it are the 40m dipole in my backyard and the 28-ft. wire (with three radials) described in the KX-1 manual. The 28-ft. wire is the only antenna I’ve ever used when operating portable.

While I’ve had good success with the wire, I knew I could do better, So, last night, at our club’s AMP Team meeting—where AMP stands for ARROW Mobile and Portable—I tried something new. I built a 67-ft. doublet from some 30-ga. wire I have and fed it with some twisted-pair wire. Theoretically, I figured that if I made the twisted pair a half-wavelength, then I’d have a relatively low impedance at the rig.

I cut the two elements, and then had a brain fart and cut the feedline to the same length. Now, theoretically, that should be bad, but I decided to hook it together and see what it would do.

I stripped the wires, and using a dogbone insulator as the center insulator, used wire nuts to connect the feedline to the antenna elements. At the end of the elements I just looped the wire and then tied a piece of string to the loop. Using a tennis ball on the other end of the string, I got the string over a branch and the wire up into the trees. The antenna was up only about ten feet, and I got some ribbing from one of my friends about it making a good NVIS antenna, but I pressed on anyway.

I connected the feedline to the binding posts on the BNC-binding post adapter, turned the KX-1 on and hit the antenna tuner control. Despite having only a quarter-wavelength of feedline, the tuner tuned it up just fine.

The real test was whether or not I could make any contacts. Tuning around a bit, I was very much encouraged. There were lots of signals, many of them S7 and above. Just for kicks, I called CQ around 7040, but when I didn’t get a response, I tuned around a bit.

Doing so, I nabbed Jozef, WB2MIC, in Wells, VT around 7058. He had a fine 599 signal, and he gave me a 559.

After a nice QSO, I tuned around some more and heard N5DY, Stillwater, OK calling CQ at 7036. He came right back to me, and although he wasn’t copying me as well as Jozef, we had a nice QSO. He was running a 4 W homebrew transmitter.

Finally, I worked Greg, AA8V, in Frostburg, MD. He gave me a 459 report.

All in all, I’d say my new antenna is a big success. Being made from 30-ga. wire, it’s very light and I got it up into the trees pretty easily. And it also turned out to be a good performer.

I’ll be trying it out again at the next AMP Team meeting. Next time, I’ll take my antenna analyzer along to actually measure the impedance.

Come and Get It!

The June 2007 issue of the Flying Pigs’ Bacon Bits Quarterly (BBQ) is now online. Articles include:

  • Harbor Freight 45W Solar Panel “Kit” — By Rich Arland, W3OSS
  • Hams Are Cheap! by yours truly, FP #1171
  • Hamming It Off the Grid – By Dennis Ponsness, WB0WAO, FP #347
  • Building the SW-40+ — By Dan Lautenschleger, AB9ME FP#1570
  • Run For the Bacon Roundup – By Larry Makoski, W2LJ FP#612

Oink Oink!

New Kit Provides Variety of Functions

According to Gene, N0MQ, Wayne McFee, NB6M has designed a new kit for the 4SQRP Group us. It is an HF Test Kit with the following functions:

  • Frequency Counter
  • Crystal Oscillator
  • Wideband Noise Generator
  • Audio Oscillator
  • 50 ohm Dummy Load
  • RF Probe
  • Time Domain Reflectometer

This kit is all thru hole parts with no SMT parts. Because of the large cost involved, 4SQRP needs to pre-sell the kits to raise the money to fund this kit. 4SQRP Group does not have dues or any other way to fund this offering so they ask that you prepay by sending them a $50.00 check. They will not cash it until the kits are ready to ship. The kits that 4SQRP Group sells are used to pay for Ozarkcon QRP Convention.

You can find more information on the 4SQRP website, including a picture of the prototype and the manual. This website has information on all of the 4SQRP kits currently available.

Why QRP?

On the QRP-L.Org mailing list, there’s been some discussion about why people become QRPers. Here’s the list so far:

  1. High power is too easy. These folks enjoy the challenge of QRP.
  2. There are restrictions on antennas where they live.
  3. They’re tree huggers who want to conserve energy.
  4. They like to build their own equipment.
  5. They’re too cheap to buy high-power gear.
  6. They’re campers or hikers and like to take ham gear along with them.
  7. They blew up their finals and are too lazy to get the rig fixed.

Rick, KC0PET opined, “I am a tree hugger. Every time I climb a tree to hang a QRP antenna, I hug
the tree…keeps me from falling.” I’d add a #8: QRPers are more fun to hang out with than the QRO guys.