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Reviews Categories | QRP Radios (5 watts or less) | Small Wonder Labs PSK 20 Transceiver kit Help

Reviews Summary for Small Wonder Labs PSK 20 Transceiver kit
Small Wonder Labs PSK 20 Transceiver kit Reviews: 21 Average rating: 5.0/5 MSRP: $$100
Description: Derivative of the SSB transceiver appearing in the April 1997 issue of QST. Streamlined for ease of construction and alignment, and many of the higher installation-skill components have been designed out. Intended as an entry- level platform for PSK31 use, it covers the 14.0695-14.073 segment of 20M where most of the PSK31 activity is found. The design retains the same relatively high dynamic range of the QST SSB rig as well as good transmit IMD characteristics.The rig is crystal-controlled and was designed to work with the popular (and free!) DigiPan software. Output power is 3W PEP. The crystal control provides excellent stability and its simplicity keeps the cost low. Performance characteristics for all versions are similar
Product is not in production.
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WA6L Rating: 5/5 Dec 14, 2007 09:37 Send this review to a friend
Another great kit from Dave Benson  Time owned: 6 to 12 months

This is my second kit from Small Wonder Labs. Like the first, this one was elegantly designed, easy to build, and superbly documented. I completed the kit in one day, and had no problems and no questions about the procedure or the parts. This kit is well within the abilities of a first-time builder who has some soldering skills.

I also opted to go with the PSK-20 enclosure that is offered by Small Wonder Labs. I think that was a good decision, as the kit goes into the enclosure in 5 minutes flat and looks great.

After the build. I applied power to the unit and went through the well-documented alignment procedure. It all worked as designed, except for the output power. I was barely getting 1 watt out. After considerable troubleshooting, I decided it was a bad final PA. I emailed Dave Benson with my measurements and he agreed. He sent out a new PA, and I am now getting 3 watts out.

Like the other Small Wonder Lab designs, the PSK-20 is a simple, well-designed rig. There are no "bells and whistles" -- not even a power LED. But also like Dave's other designs, it works very well and is just begging for user modifications. There is plenty of room on the PC board and in the enclosure if you want to add that LED or make other changes.

On-air performance is spectacular for a rig with this price and parts count. The receiver is hot, and compares favorably (using the waterfall for comparison) with my desk rig. The power output is a limiting factor, but with 3 watts and good conditions, you can do very well on PSK. My very first contact was with South America.

Some other reviewers have made comments concerning audio levels on the PSK-20. I agree. You have to be very careful about over-driving your PSK signal. There is no ALC or IMD indicator on the PSK-20, so I recommend contacting a friend on PSK who can watch your signal as you make sound-card adjustments. Once you find the right setting, leave it there!

I do have to make one final comment about Small Wonder Labs. This is a one-person company, and that one person (Dave) does everything. He also has a personal life and (as of this writing) is building a house. So you aren't going to get a one-week turn around on orders or on email. Some orders will take months to ship.

I am fine with this. I am just grateful that the Ham community has someone like Dave who can design these great little kits and offer them at such reasonable prices. However, you need to know ahead of time that you are not dealing with a large commercial enterprise. Home-brewers and kit-builders are generally patient people, so this shouldn't be an issue.


John, WA6L
K1QN Rating: 5/5 Nov 21, 2007 06:52 Send this review to a friend
Worth the wait  Time owned: 0 to 3 months
If your first QSO was 'in a certain decade', you'll probably need something like the Kronos "Helping Hands", which Radio Shack has in stock once again. It's a soldering station with a big magnifying glass.

The kit went together in 2 sessions of maybe 8 hours total. I really missed the smell of rosin in the shack! There were a couple issues. The two surface-mount inductors were hard to install, but I got through it OK. When I put it in the enclosure, I noticed that some of the wire leads contacted the metal underneath the board on the edges. I trimmed them off as best I could (I need a new pair of diagonal cutters.), then put electrical tape over the 'danger zone'. Also - there was a solder connection and it caused the rig to transmit pops now and then. I knew it had to be in the audio in / VOX circuitry, and I finally found it and re-soldered it.

Alignment was straightforward, except that my "big rig" is at the shop, and my TenTec Century 21 backup isn't a very accurate frequency standard. To get around this, I located the 33rd overtone on my 70 cm HT. I figure this gave me a frequency accuracy of about 150 Hz, which will land me in the PSK-31 subband. I used a "normal" swr/wattmeter, and it showed relative power enough to tune the transmitter - even though the needle barely moved.

The first QSO was a "reported 599" from New England to Cuba. I find the 599 hard to believe, but he had no problem with copy.

Next up: a QRP CW kit, and an amp.

VE3SJB Rating: 5/5 May 15, 2007 10:45 Send this review to a friend
wonderful little kit  Time owned: 0 to 3 months
I just built this kit earlier this week, it went together with no problems at all. There was one capacitor that was missing, but was easy to find in the junk box... the parts are labeled nicely and the instructions that come with the kit are easy to follow. Aligning the receiver and transmitter was an absolute breeze, it took a whole 5 minutes to get things working as per the manual. In the end, I spent a whole Sunday building the kit at a slow pace, checking things as I went along.

On the air performance was excellent, before I even aligned the receiver I was copying a station in New Mexico clear as can be. After building a quick n' cheap dipole in the house made from some hookup wire spanning from my kitchen to my couch in the living room, I was on the air. I worked most stations i could receive with no problem, getting RST of 599 very consistently.

Tonight will be another night on the air with this little kit, which has me excited. Overall, for the price, this kit is a definite kit you should go buy. Easy to build, easy to align, easy to use. As simple as that.
K2QPN Rating: 5/5 Aug 16, 2005 18:00 Send this review to a friend
Great radio  Time owned: more than 12 months
I built the PSK-20 about a year and half ago. I bought for use on business trips. Goes thru airport security in my lap top case without a problem.

The kit went together easily. I bought a magnifier from a needlepoint store to help my tired old eyes. Alignment was easy. I copied France before alignment.

QRP reqires a decent antenna. Hanging a wire out the window is no good. Stretch out a hook up wire dipole and life is good.

I took the PSK-20 on vacation. My antenna was an inverted vee 10 feet up. I worked stations every day - including France and Martinique.
KZ1X Rating: 5/5 Jun 3, 2005 14:47 Send this review to a friend
my 2nd one, even better!  Time owned: 0 to 3 months
Tis is my 2nd PSK-20 radio. The first one worked perfectly and I sold it to a friend. I missed having one and also wanted to do some antenna experiments, plus I wanted to try the newer version.

So, I ordered a new one in early April.

I got mine last week (yes, Dave is a bit backlogged sometimes, but you can check your order status on-line at all times) and I built it in only a few hours.

Kit was, as usual for this vendor, perfect, no missing parts, a pleasant build. Worked 100% on initial power up.

New model does NOT use a serial connection, so, it's great for newer laptops. Just simple audio in and out, power, and an antenna.

The new model has a really pro-grade receiver, with a high performance Mini-Circuits mixer, and an improved transmitter section. Both the driver and PA stage transistors have large heatsinks, and the PA is ballasted with individual resistors for good dissipation. The crystal-ladder filter now has case ground leads to lower blow-by. There's a W7EL type front-end clipper. Gilbert-cell mixers are used in the right places, and all ICs are socketed.

There wasn't much wrong with the old design, but the new one is a big step forward. That Dave can sell such a radio at the same price as the older model is something to yell about.

This radio represents the absolute best value in amateur radio today. A good secret can't be kept. Small Wonder they are always sold out! ;-)
NW0LF Rating: 5/5 Apr 15, 2005 06:48 Send this review to a friend
Awesome!  Time owned: more than 12 months
Built this kit for Boy Scout Jamboree on the Air 2 years ago and from S. Florida, made contact with scouts in New Zeland. They couldn't believe we were running 2.5W into a Dipole at about 30 ft while they were running 65 watts into a beam on a hill. I had lots of fun building this kit and the support was great when I had problems. Buy it, build it and have a blast on PSK!!!

73, Tom K9WLF
G6CNQ Rating: 5/5 Apr 15, 2005 05:05 Send this review to a friend
Great with minor niggles  Time owned: 0 to 3 months
Hi All
Having now built this kit and smoke tested it on air I can honestly say it is a great ket that performs as well if not better than my Kenwood TS2000 and Tigertronics Signalink SL-1+

Construction time for me was a tad under 6 hours from start to on air testing, this was over a period of 2 weeks as there was an incorrect component supplied which to 7 days to arrive due to sluggish postal services.

Setting us was simplicity and output is a little under 4 watts. I found there was too much drive for my laptops soundcard so had to attenuate the output slightly.

My only critism's are:

1. Protracted delivery time (Took nearly 7 weeks)
2. I would like an on off switch and power LED
3. Pot to adjust the output to the soundcard

All in all a fantastic piece of kit

Terry Genes
AD4MZ Rating: 5/5 Sep 26, 2004 02:38 Send this review to a friend
A fantastic little radio and half the fun is building it!  Time owned: 0 to 3 months
Haven't melted solder in 5
years and was wondering if I could still do it and see the much smaller parts. The PSK-20 was
addictive. Before long I was on the page that said "that's it- board assembly is complete!".
Connected the antenna and DC power and followed the clearly written alignment instructions without
a hitch. This morning I saw a CQ from N7XS and made my first PSK 31 call ever. I could hardly
believe I was seeing my call sign being sent back to me from Bud in Idaho. What a neat fun mode.
He was surprised to hear that I was using the PSK-20 and an indoor attic 20m dipole from NC. My
second QSO was with an IK5 station in Italy but the RTTY contest was killing the PSK fun for me.
Dave your hard work on the design, high quality board, parts, and directions put the real fun back
into the hobby. Thanks for everything. Now I want a small all band or at least 3-band version. I
enjoy winding toroids. Is it on the drawing board?

SV1ENS Rating: 5/5 May 17, 2004 04:58 Send this review to a friend
Great little travel radio...  Time owned: more than 12 months
Easy to build, tune, and operate. Original RF transistor was 2.2 Watts, replaced with alternative for 4 Watts.
Both pre-sale and after-sale support was great.

This little gem is always packed with my tiny IBM thinkpad and a small zip-wire dipole when I travel.

KD5WBS Rating: 5/5 Mar 5, 2004 16:49 Send this review to a friend
Great Fun.  Time owned: 6 to 12 months
Easy to build and works great. I've build several kits and this one is my favorite. Its so simple to use. After 6 months I still work this more then my base rigs. 5 watts to my G5RV works almost any station I can hear.
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