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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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K5CPF Rating: 5/5 Oct 3, 2014 20:18 Send this review to a friend
Exceeds Expectations!  Time owned: 0 to 3 months
I picked one of these up on eBay this week for $100. It was already assembled and ready to use.

I purchased a MFJ-1786, which I temporarily mounted it vertically 2ft above ground on a camera tripod to test the radio using 100' of RG-58.

I was able to copy PSK31 stations as far away as Reunion Island (> 9,500 miles).

Transmitting less than 1 watt (into that 100' of coax to the antenna 2ft above ground), I was copied by stations as far as 2,300 miles away in Canada, according to the pskreporter website. My first QSO was to a ham in Georgia.

Needless to say... I AM IMPRESSED!!!
KJ4QAN Rating: 5/5 Apr 14, 2012 01:05 Send this review to a friend
Keeping computer generated noise out of your waterfall display.  Time owned: more than 12 months
The SWL PSK20 is an excellent little radio. As you may know, it is currently unavailable from Small Wonder Labs.

The computer I use is the ACER Aspire One Netbook running Digipan. When running on battery power, the waterfall is completely clear of noise (little yellow specks to the uninitiated). When the battery got low after about an hour, I would plug in the power adapter/charger. The noise on the waterfall increased to the point that most signals could barely be seen. Message errors also increased. That little adapter is obviously a swither supply. To filter out the noise I bought a package of two Radio Shack snap-together choke cores (273-104). I wound 10 turns of the line between the supply and computer onto each one. This cleared up most of the noise. To clear up the rest I snapped on 4 more Snap-Choke cores (273-067). It wasn't until I snapped on the fourth core that all the supply generated noise disappeared. This took up every bit of the line. Snapping cores on the AC line side made absolutely no difference. Snapping cores onto the speaker and mic inputs also helped, but not nearly as much as putting them on the supply side. I added a snap-on core to each of those lines anyway for good measure.

I recently replaced the computer battery pack with one that gives twice the life on a charge. At over 4 hours of life per charge the noise problem is no linger an issue. Four hours of PSK is enough for me.

I'm sure you may be able to find cores at a cheaper price than RS. Give it a try if noise on the waterfall is a problem.
HS0ZIB Rating: 5/5 Jun 14, 2011 19:21 Send this review to a friend
3000km/watt on first QSO  Time owned: 0 to 3 months
I bought this little rig (already built kit) from an Eham classified ad, and the seller (Steve KW4H) shipped it direct to my QTH in Thailand by UPSS. (Thanks Steve for an excellent service from you).

I am still constructing my radio shack, so I drove 500 meters to the nearby beach and threw up a PAR End-Fedz 10/20/40 antenna, plugged the rig into my laptop, attached the power leads to my car battery and called CQ.

It was about 1645 local time and still daylight. My CQ was answered by UN6GT Valery in Almaty, Kazakhstan, some 4,600km west of my QTH where it was still broad daylight in the middle of the day.

On this initial QSO, I was concerned not to overdrive the PA stage, so I had turned down my audio drive until output PEP was about 1.5 watts - that equates to more than 3,000km per watt for my test QSO.

The results speak for themselves....

Thanks to Dave at Small Wonder Labs for making a great rig, thanks to Steve KW4H for selling this little beauty to me, and thanks to PAR for making such a great wire antenna!

AE6NG Rating: 5/5 Feb 28, 2011 09:43 Send this review to a friend
It's fun building this kit!  Time owned: 0 to 3 months
I got this kit awhile ago and it had been sitting on my desk. I was hesitant to start building it worrying that I might not have time to finish it.

Well, last weekends, I decided to build it. It took me two 4 hours weekends to finish it. I took it slow building it and always double checked before soldering the components.

I powered it on at the first time and it started to show some noise on the Digipan. Too bad, there was no activities during the night, the band was dead. The next morning, I saw a lot of activities on the band.

I answered some CQs and the rest is history. I got decent reports from TN and Cuba. And I only used a G5RV Jr. laying on the roof of my townhouse. I use LDG-11 Pro for the antenna tuner. I use a cheap USB dongle sound card, and the waterfall is quiet clean.

By the way, RX and TX adjustment was also straight forward. Since I don't have a Wattmeter, I used my other rig for the TX adjustment, for the strongest signal received. RX adjustment was easy, too.

It's time to make my portable dipole or EFHW antennas for field operation. It would be so much fun.

It's a recommended kit! It's fun building it, and it's much more fun operating it.
KJ4QAN Rating: 5/5 Jan 11, 2011 06:36 Send this review to a friend
An excellent QRP radio for PSK31  Time owned: 6 to 12 months
This is an excellent little radio. I have the PSK20 and got the optional enclosure which beautifully done with nice thick paint. Itís really clever the way that it all fits together with only 4 screws! It is a perfect kit for a first time builder. I put many Heathkits together when I was a kid, some of them very large, and this little kit took me back to those days. It was a pleasant surprise to see that much quality packed into a cottage industry kit. Dave Benson has really put together another nice kit.

My little radio puts out a little over 3.5 watts. The coax is 50 feet of RG-8/U low-loss cable to a RadioWavz dipole, inverted-V at 15 feet, that was carefully trimmed (ľ inch at a time) for 14.070 MHz. I live in Florida and I have QSL cards from Saint-Lo France, Vancouver, Ontario, Ecuador, and French Guiana. The other guy is always surprised that my signal is so good at 3.5W when they are using 30-35 watts. This little rig is optimized for that narrow band of frequencies between 14.070 - 14.073 MHz.

The plating of the circuit board is first rate. The barrel plating is heavy and the alloy Ďwicks -upĎ solder. This makes solder flow perfectly even with a 25 watt pencil and a minimum amount of solder is required to make a perfect joint. I have seen a 100,000 boards in 22 years of manufacturing QC, and Daveís supplier of circuit boards gets 5 stars The masking is also perfect; absolutely no bubbles or running. The parts silkscreen has a couple of very minor errors but Dave clearly points them out. Engineering Change Notices (ECN) are a fact of life and there are more ECNs in your favorite $7000 radio than you would like to know. Be thankful that you are building a radio that you can fix yourself. The assembly diagrams are clear and the instructions are concise. The parts are packaged in a logical way making them easy to find.

I broke a toroid while winding it by pulling the wire to hard. I emailed Dave at 10:30PM and said, ďHouston we have a problem. At 6:30AM the next morning, Dave replied that he would send me another that same day. A couple of days later I got my toroid. Now thatís customer service! I sent Dave a couple of dollar bills, even though he didnít ask for them. Hereís something I learned while building this kit. Donít try to wind your toroids so tight that the wire lays directly against the metal. Itís not going to give you a better coil with higher Q, and youíre just wearing yourself out. I tested this minor point very carefully. Just snug up the turns enough to keep them in place. Dave does point this out somewhere. He knows what heís talking about.

When I got into ham radio not long ago, I wanted to focus on QRP. Going QRP brings back some of the challenge and simplicity of the old days. Daveís little radios are perfect for taking to the park and sitting at a picnic table with a wire hanging in a tree and another laying out for a counterpoise. I use Digipan running on an Aspire One notebook computer. With that, and a 12V gel cell or a couple of 6V lantern batteries, you can have a pleasant afternoon talking to people around the country.
K4ALE Rating: 5/5 Jun 3, 2010 06:39 Send this review to a friend
Very fine rig  Time owned: 0 to 3 months
This is my second SWL kit. It is not a beginner's kit, but as a second or third project, this is one of the finest experiences you can have, both with kitting and with PSK-31. In large part, John, WA6L, has covered the main points and I agree with him. I got the SWL enclosure, which looks very professional, and I found the construction instructions, layout, design, and other information to be simply beyond criticism.

My personal contribution involves a hitch, which really demonstrates how much of a quality operation SWL and this rig are. I got my rig constructed in about 8 leisurely and well-paced hours over two days. After double checks, I began the "smoke" testing and alignment. The receiver worked amazingly well, and as others say, about equal to full size rigs; it is a monument to the single down conversion design. However, once aligned, I discovered that my output was about 250 mW. I tested within my limited ability and contacted Dave Benson at SWL. His communications were great, and after investigation, suggested that I send the rig to Alan Wilcox, a repair referral on the SWL website. See my 5.0 review for Alan elsewhere.

Alan addressed the matter quickly. It was a warranty matter involving a bad component [not the fault of anyone]. Alan fixed it, realigned the txmr section, and measured about 4 watts out. It was back home, fixed, in a week or so.

Once home, I played around with it until I got my computer set up correctly. Experiment with all of the settings; my breakthrough was discovering the speaker volume setting needed to be nearly 100% for full modulation of the signal and maximum power output.

Then the fun really began. I had erected a qrp half-square built out of #26 twisted pair from an old computer serial cable. It was in the trees of my backyard about 25 feet up. I got the computer-rig set up correctly on my main home station antenna, and then headed out to the back yard with a battery to see what I could do. It was evening and I quickly made a contact with Norfolk, ENGLAND, from Central Virginia--a distance of 3848 miles. Four watts, and minimalist antenna, at almost 1000 miles per watt. Fine performance by any standard.

PSK-31 is a perfect mode for qrp and this fine rig demonstrates that 4 watts has real legs. So, why do we ever use more than 20 watts?

Go for this very fine rig!
NE7AA Rating: 5/5 Dec 14, 2009 17:50 Send this review to a friend
Great fun  Time owned: 0 to 3 months
Great fun and instructions.
cant wait to get the 30 and 40 versions.
73 Rich NF8V
VK4JAZ Rating: 5/5 Aug 24, 2009 16:52 Send this review to a friend
Outstanding kit  Time owned: 0 to 3 months
This is not the first kit from Small Wonder Labs that I have built, so I guess I knew what to expect. I was not disappointed.

Building was a dream and most enjoyable. Instructions were first class. I run a 100% qrp station so don't have a 'big rig' to help with the aligning, but followed Dave's instructions to the letter and had my very first digital qso straight thereafter. Great signal, came back the report, and nice and clean with no splatter.

I am thrilled. Thanks again, Dave.
WA3DNM Rating: 5/5 Jun 14, 2008 12:24 Send this review to a friend
AMAZING Experience  Time owned: more than 12 months
This is the best buy in ham radio today. The kit went together seamlessly in about 6 hours. Worked 1st time out of the gate, no smoke. Was not sure I had it aligned properly until I had QSO's with Nova Scotia @ 1100 miles, Georgia @ 1000 miles, Michigan @ 653 miles and IL at 693 miles. My lowest RSQ was 567 with 2 out of these 4 contacts giving me a 599 - all using this great radio @ 2.5 watts and a dipole antenna IN MY ATTIC! Oh, the last QSO with Bobby, KC9JWU, he gave me a 599 report, and he was also using 5 watts..... the band was not in exceptional shape!!!

Want to have some fun? If you are like me, approaching 50 years in the hobby, or if you are a a newby, pay your $125.00, order a kit, take your time putting it together and ENJOY!

This is what ham radio should be about...


5R8GQ Rating: 5/5 Jun 10, 2008 20:21 Send this review to a friend
Must Have QRP Radio  Time owned: more than 12 months
There is not a hole lot that I can add to all the "5" reviews. I built one of the very first kits when they were first offered,(over 10 years ago) before Dave Benson streamlined the design. It is am amazing performer and worked great from the first time I applied the power I saw PSK signnals on the waterfall. The board, part and instruction quality is all first class. My first QSO with this rig was with VK2CA from my California QTH, using a multiband vertical antenna. That is over 2,000 miles per watt, and I have the "1000 Miles Per Watt Club" certificate on my shack wall from this rig. The rig is still going strong with not one problem....ever.

The rig is built in bite sized stages and there are few toroids to wind. It's amazing that you can spend $100 USD on a rig and work all states and DX with a modest antenna.

Based on this experience, I have also bought and built the PSK-40, the 80m Warbler (little cousin to this rig) and the now discontinued PSK-10. They all work as fabulously as the PSK20.

Yes, there is a wait for this rig, as for most of Dave's kits. It's just a small operation, that's all. Dave is a true "QRP guru" and everything he puts out is magic. Just order one, it's worth the wait.
73, Ken 5R8GQ/AD6KA
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