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 Previous: Atlantis to Ferry Initial ARISS Ham Gear to International Space Station |  Next: USTTI Class of 2000 Learns About Amateur Radio |
By Ken Hopper, N9VV
September 7, 2000
As a mode, none since the inception of CW has caught the attention of the QRP community as PSK31 has. This summer, low-power operating enthusiast Ken Hopper, N9VV, purchased and put together the Small Wonder Labs PSK-20 PSK31 transceiver kit. The experience has made him a huge promoter of PSK31.
Author N9VV gets unsolicited "cat help" while building the Small Wonder Labs PSK-20 kit. [All photos courtesy of the author] |
I just finished building the PSK-20 PSK31 transceiver kit from Dave Benson, NN1G, at Small Wonder Labs. You may have heard about it at Dayton or you might have seen the wonderful writeup in June QST where Howard "Skip" Teller, KH6TY, and Benson wrote a seven-page article all about the little gem.
The PC board quality is superb. Plated-through holes and silk screening the hallmark of Dave's excellence in kitting. The instructions are step-by-step and sharp as a tack. Nothing is left out, and there is no extraneous fluff either. The pictorials are clear and uncluttered.
Dave anticipated most of my questions. I had one problem where I installed the shorting jumpers on a test point at U6. This resulted in a carrier instead of SSB. Dave says he will eliminate the jumper or clarify the use of the test point.
The completed Small Wonder Labs PSK-20 board. |
The parts are clearly marked and all large enough for even this fat-fingered OT. There are three surface-mount inductors that you simply need to press down while lightly touching with a soldering iron. Easy stuff for sure. Four toroids and these are wound with normal hookup wire (not magnet wire that you have to strip). Couldn't be easier to align--just peak the receiver and peak the transmitter, and you are on the air. Literally seven hours from start to first QSO--and I took breaks for a trip to RadioShack for a 4.7 pf cap (and for lunch--but not at RadioShack).
If you have a computer with a sound card, you are ready for PSK31. You don't have to wire any connectors--just plug in AUDIO IN, AUDIO OUT, and PTT from a simple 9-pin cable. The DigiPan software from Skip, KH6TY, is amazing in itself as it offers a panoramic display. You will be astonished if this is your first look at the next generation of DSP tuning. You have no tuning knob. You simply point and click on the frequency you desire and start the QSO!
Author Ken Hopper, N9VV/m, on PSK31. We don't recommend driving while operating this mode, but it's great to have along while on the road. |
On a recent Sunday I counted 22 stations packed in every 50 Hz of space between 14.0695 and 14.0705 MHz. Tremendous DX activity all day. This new panoramic transceiver and no tune software is a huge design leap forward in hamming. Set your dial to 14.073 LSB, and the software does the rest. I was somewhat confused and concerned about the use of LSB (other conventional ham gear uses USB by convention or default on 20 meters, and PSK31 uses USB), but it turns out to be completely transparent to the other operator. The DigiPan software accommodates the choice of LSB in its low-to-high conventional frequency panoramic display. High tones are subtracted from 14.073 as you tune lower in the band. It all works "automagically." Not to worry!
Yeah, I know about the narrow-filter crowd that thrives on ever-smaller non-ringing variations in the IF. Well suspend belief! This transceiver has a 4-kHz bandwidth and crystal control for (literally) rock-solid stability. The broad bandwidth is specifically designed to work with the new DigiPan software.
If you grew up using CW in the 1960s you were used to wide bandwidths and "tuning" in your head. Harry, W9TT, taught me those skills on the NTS. We are back to that era with wideband signal display but now we are blessed with super narrow DSP software that I'd bet is better than your transceiver IF at 31.5 Hz.
Please take time to check out this wonderful new keyboard-to-keyboard style QSO mode. It is easier than RTTY, conserves bandwidth and works better with weak signals (QRPp) like no other mode--copies right into the noise. You won't see a signal or hear it, but the QSO characters march across the screen.
Thanks, Dave and Howard, for sharing your engineering and kitting expertise with us mere mortals!
Editor's note: Ken Hopper, N9VV, lives in Naperville, Illinois. An ARRL member, he was first licensed in 1960 as KN9DNY. Hopper says he's been having a ball working DX with just a couple of watts and a wire antenna. Hopper says his first contact with the PSK-20 was with N5NE while he still had the transceiver clip-leaded together on his operating desk. "I have stopped calling CQ DE N9VV/QRP and now sign just N9VV," he says. "No one believes me that I am actually running 2 W to a W9INN dipole. This summer, he worked Australia and Japan for his first PSK31 DX. "I could hear a 4X6 and an SP6 and others that I couldn't recognize," he said, "but my little signal just wouldn't quite get there." He has a Web site devoted to the PSK-20 project and other aspects of PSK31 at http://home.uchicago.edu/~khopper/psk20project.html.
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