Category Archives: Kits

Radio life after death

A guest post by Troy Riedel:

This is a sad story.  Well, it’s sad for me.  But hopefully my sad story will yield “radio life” for somebody else and that life will bring them joy.

I’ve been an SWL’er since the early-90s.  Due to the decline of international broadcasters, “collecting” has become just as – if not more – important to me than listening.  I’ve always been fond of the Sony ICF-SW100 pocket radio.  I often read here on this blog about Thomas’ affection for it.  To make my dream a reality, on 19 November 2017 I found the perfect SW100 (with the leather case) and I purchased it.  It did not disappoint!  That radio has to be the most sensitive radio for its size out there.  No, correction – that little baby has held its own against any other portable shortwave radio (of any size) that I own (I have 17 or 18, incl. this SW100).  That’s quite amazing for a true pocket radio.

But please allow me go back to the beginning of my story.  Once I acquired the ICF-SW100, I assembled a “kit” … piece-by-piece (remember, I’m a collector).

I surmised that the SW100 would fit into the Sony ICF-SW1 case – and I was correct (sans the SW100’s leather case).  The SW1 case was one of my first purchases for my SW100 as I wanted something rugged to protect it.

The Sony AN-1 antenna works great with the SW100, and that was part of my kit.  Of course, I also wanted the OEM Sony Compact Reel Antenna.  “Check” – found one on eBay!  The OEM AC adapter? Yes, “check” that one off the list.  A photocopy of the OEM manual would not do – I found an original on eBay and “check”, that was added to the kit.

I already owned a Sony AN-LP1 (active) antenna.  That would not fit into the case, so I added a TG34 active antenna that I already owned (that’s a Degen 31MS clone).  Why?  I gotta have a ready passive antenna in my kit.

Wait, who wants a 30+ year old OEM set of earbuds?  Exactly, neither do I.  This is the only thing I did not want to be OEM!  I bought a new pair of Sony earbuds (off Amazon) to throw into the kit.  Other than the TG34, everything in the kit had to be Sony.  In the end, this handy little case was my Eutopia – it had everything I needed in its own “shortwave bugout kit”.

Of all of the radios in my shortwave arsenal, this was by far my favorite.  Hobbies should bring us joy.  So even if there weren’t many broadcasters to listen to, this little pocket radio never failed to bring me joy.

The last time I really used this radio was June-August 2020.  My newborn grandson was in the NICU far from my son’s home.  I “deployed” (with my SW100 bugout kit & 5th wheel camper) to my son’s very rural & very remote farm (275-miles from my home).  I was there to tend the farm, solo, for that period of time while my son and his family could be with my grandson at a specialty hospital some 350-miles away.  During this stressful & physically demanding time – tending to more farm animals than I care to mention and rustling bulls that escaped from the pasture – my SW100 was the only friend that I had.  It provided many, many hours of enjoyment.  Literally, other than a neighbor about ¾ of a mile up the road my ICF-SW100 and I were alone (not including the 50+ animals I tended to) from June through August.

Fast-forward to the present: last weekend I reached for my kit and I removed the my SW100.  I turned it on and there was no power.  Not surprising but actually very unusual as my NiMH Eneloop batteries typically last for a year or more inside my radios in “storage”.  I reached for the battery compartment, I felt an anomaly on the backside of the case and imagine my horror seeing this as I turned it over!

Surprisingly, there is zero damage to the Eneloop batteries (they did not leak).  I can no longer power the radio via ANY batteries, but amazingly the radio seems to operate at full capacity via AC Adapter.  Whatever happened inside the radio, it still seems to operate (though admittedly I haven’t taken it through all of its usual paces).

Unfortunately, a pocket radio that only operates via AC power does not suit me.  There is a better option: my loss may be someone else’s gain?  I am sending the radio and the necessary components to Thomas’s friend Vlado for a full autopsy (Vlado emailed that he has worked on these radios for years and has “never” seen this issue before).  After the autopsy, my radio will become an organ donor.  The remaining healthy components of this radio – and there are many – will be used for repairing other SW100s (singular or plural).

Strangely, I cannot detect any other “trauma” to the radio other than that one melted corner.  The battery compartment *seems* undamaged though I refuse to open the case as I do not want to accidentally damage the radio’s healthy components (I’ll let the professional “coroner” do that).  I am looking forward to the coroner’s report because I need to know what the heck happened to my baby?!

In closing, though we’ve only had a 3-year plus relationship I can honestly say this amazing little pocket radio had become a great friend.  I’m sure it’s grief, but I am considering liquidating the remainder of my radio & antenna collection – my heart just isn’t “in” to SWL at the moment.  And the timing of this is just awful for me: I’m having surgery Tuesday for an injury I incurred eight months ago while tending my son’s farm.  I had big plans that my SW100 and I would pass the time while I convalesce.  But alas, my buddy will be headed to radio heaven as an organ donor.  May others benefit from my loss.

Guest Post by Troy Riedel

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Steve builds a DC30B QRP Transceiver

DC30B QRP Transceiver ProjectMany thanks to SWLing Post contributor, Steve (KZ4TN), who shared the following guest post originally on, but I’ve posted it here as well because I’m sure it’ll resonate with those of us who love building kits!:

DC30B QRP Transceiver Project

by Steve Allen, KZ4TN

I wanted to build a lightweight backpackable transceiver I could take hiking and camping. I chose the 30 meter band as it is specific to CW and the digital modes. I am also in the process of building Dave Benson’s (K1SWL) Phaser Digital Mode QRP Transceiver kit for the 30 meter band. Also, a 30 meter antenna is a bit smaller than one for 40 meters and the band is open most anytime of the day.

I sourced the DC30B transceiver kit, designed by Steve Weber KD1JV, from Pacific Antennas, It appears that they are now (10-11-20) only offering the kit for the 40 meter band. The following information can be used for the assembly of most any kit that lacks an enclosure.

Lately I have been finding extruded aluminum enclosures on and They come in many sizes and configurations. I like to use the versions with the split case which allows you to access the internal enclosure with the front and rear panels attached to the lower half of the enclosure. Most of these enclosures have a slot cut into the sides that allow a PCB to slide into the slots keeping it above the bottom of the enclosure without having to use standoffs. The one requirement for assembly is that the PCB needs to be attached to either the front or rear panel to hold it in place.

DC30B QRP Transceiver Project

As the enclosure is anodized, I didn’t want to rely on the enclosure for common ground. I used a piece of copper clad board that I cut to fit the slot width of the enclosure and attached it to the back panel. I was then able to mount the transceiver PCB to the copper clad board with standoffs. This basic platform of the enclosure with the copper clad PCB provides a good foundation for any number of projects. All you have to do is mount the wired PCB on the board, install the components on the front and rear panel, then wire it up.

DC30B QRP Transceiver Project

I wanted to have the choice of a few frequencies to operate on so I searched eBay for 30 meter crystals and found a source for 4 different popular frequencies. I installed a rotary switch on the front panel and added a small auxiliary PCB with two, 4 pin machined IC sockets. This allowed me to plug the crystals into the sockets. I wired the bottom of the socket PCB first using wire pairs stripped from computer ribbon cable leaving extra length. I marked the wires with dots to indicate which sockets each wire pair went to so I could solder them onto the rotary switch in the correct order. It was tight but I always work with optical magnification so I can see exactly what I’m doing. I have used this crystal switching method in the past with good success.

DC30B QRP Transceiver Project

DC30B QRP Transceiver ProjectThe rest of the assembly was straight forward. I find that most kits are well designed and documented, and if you take your time and follow the directions carefully all should go well. The two most common speed bumps seem to be soldering in the wrong component or bad soldering technique. I double check all component values and placements prior to soldering, and I always use optical magnification while working. I inspect each solder joint and look for good flow through in the plated through holes, and make sure there are no solder bridges.

DC30B QRP Transceiver Project

DC30B QRP Transceiver ProjectThe finished product. I bought a Dymo label maker and it works very well for projects like this. I love using these enclosures and they are a leap forward from the old folded aluminum clam shells I used in the past. I could stand on this without causing any damage. Power out is 1-3 watts depending on the DC power in. The receiver is sensitive and the ability to choose from four frequencies is a real plus.

73 de KZ4TN

Steve Allen
Elizabethton, TN

Gorgeous work there, Steve! Thank you for sharing!

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Win an MFJ-8100K shortwave receiver kit!

After posting Ron’s note about the MFK-8100K receiver kit, I touched base with MFJ and they have kindly donated a new 8100K kit to us for an SWLing Post giveaway. Thanks, MFJ!

This giveaway is open to anyone, anywhere. MFJ will ship it directly to you if there are no Covid-19 shipping restrictions to your country.

Here’s how to enter the giveaway…

Simply comment on this post and tell us about your favorite kit that you’ve built. This can be your first kit, your last kit, or anything in between. Don’t just give us a model name, tell us what made it a fun or special project.

If you’ve never built a kit, but are eager to do so, tell us why you would like to build the MFJ-8100K! Do you have a soldering iron?

We simply want to make sure a kit builder or want-to-be kit builder gets this prize! We’d even invite you to share a short post about building the MFJ-8100 (no obligation–only if you wish).


We will pick a winner at random from the valid comments in this post on Wednesday, September 23, 2020 at 16:00 UTC.

This means you must enter a valid email address in the appropriate comments field (not within the comment text itself) so that we can contact you.

Of course, the SWLing Post doesn’t sell or share emails–never have, never will–this is only so we can contact you to obtain your shipping address if you win. Feel free to use a throw-away email address if you wish.

This is all about taking us on a great kit-building nostalgia trip, so have fun!

Click here to comment with your kit story and enter the giveaway.

Many thanks again to MFJ Enterprises for sponsoring this contest!

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Ron reminds us that MFJ still offers a shortwave radio kit

Following up on our recent MFJ post, SWLing Post contributor, Ron, writes:

Another thing about MFJ is they still offer the MFJ-8100 as a kit or built. This is the only regenerative receiver available as far as I know.

Mr. Jue and his guys did a couple of tweaks like limiting band coverage to insure stability, using 1/8 inch 3.5mm stereo phone jacks and use an LM386 audio IC to drive headphones or speaker.

The whole thing is in a metal enclosure to minimize hand capacitance found in most regens.

The QRP crowd likes to use the 8100 with flea power CW rigs, it’s that good.

And it’s been in production far longer than the Heathkit GR-81 or any of the Knight Kit regens, too.

Thank you for sharing that, Ron! I had completely forgotten about this little kit when someone recently asked about the availability of Ten-Tec regen receiver kits (that are, sadly, no longer on the market to my knowledge)! I might have to grab one of these kits–looks like a fun one to build.

Click here to check out the MFJ-8100K.

By the way, I also believe the NM0S Ozark Patrol regen kit is still available from the Four State QRP Group. Click here to check out the product page. It doesn’t have a metal enclosure like the MFJ, but it’s also a fun kit to build.

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List of electronics and radio surplus outlets

Many thanks to SWLing Post contributor, Neil Goldstein, who writes:

I added a sub-page to with a list of the remaining electronics and radio surplus outlets I was able to find and verify. The list is evolving, but is complete enough to publish at this point. Enjoy!

Many thanks for sharing, Neil!

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Adding CW mode to the EA3GCY DB4020 Dual-band 40 and 20M QRP Transceiver Kit (Part 2)

Many thanks to SWLing Post contributor, Frank (ON6UU), who shares the following guest post which expands upon his previous DB4020 article:

The EA3GCY DB4020 transceiver now has CW mode

by Frank Lagaet (ON6UU)

After telling you all about the DB4020 SSB build I’m here with the CW part of the kit,  let’s say this is part 2.  At a certain moment Javier let me know the CW interface kit was ready for shipment and some week later it was delivered to my QTH.

Again, a well packed kit arrived in a brown envelope, components and boards well packed in bubblewrap.  I found even a board I did not expect which can hold a push button,  a switch and the connector for your morse key.  Javier thinks of everything it seems!

Unpacking the bubblewrap gave me this result,  all components in 2 bags.  In the bigger bag another 2 bags with 2 printboards,  one for the CW interface,  one for the CW filter.  Great !!  Checking the material bill resulted in all components there,  another thumbs up.

I started, of course, immediately building it because I wanted CW in the transceiver as soon as possible.  I don’t do much in SSB mode anymore and I already started missing CW on the DB4020,  so I started my KX3 to listen to while I was populating the boards.  I never thought CW was going to have this impact on me! …. ..

I started building the CW interface,  again starting with all small items.  I soon saw that the 2 relays which need to be soldered in were ideal to protect all components when the board is upside down, so I soldered them in very quickly.  I then soldered in all other components ending with the elco’s.

Next phase was the CW filter.  This board is small and came together in a blink of an eye, no problems there, the long legs of the 3 and 4 pin headers went in last.

The following day, I made all wire connections and soldered a 13pin connector,  leaving one pin out since I want to have the option to choose the width of the CW signal I’m listening to.  By cutting the FL CW + pin and adding an additional switch, I have now 500Hz or 2400Hz.  Great option, for very little effort and simple.  Another thumbs up here.

Now it was simply a matter of inserting the sub boards in the main board and all should be working.  And it did!  Hurray!  The 500Hz filter works perfectly,  filtering away all above or below stations nearby my operating frequency.

This is the result of the soldering work,  2 small boards which need to be inserted in the main board:

The CW interface still needs the 13pin header of which I cut one pin and mounted a switch to have the 2400Hz width.

The IC you see in the middle of the CW interface is the KB2 keyer which gives you several functions like 4 memories and beacon mode.  The 4 potmeters are used to set the level on 40 and 20 meters,  to set the delay between TX and RX switchover and to set side tone monitor level.   The keyer also provides functions as keyer mode A or B,  straight key function and can be set for speeds between 1 and 50WPM.   WPM speed can be set in 2 different ways.  Handy!

Here a picture of the CW filter inserted on the main DB4020 board.

The CW interface is inserted at the side of the main board,  notice the 2 wires which go to the switch to allow switch-over between 500 and 2400Hz.

(Wiring still needs to be cleaned up in this picture.)

Finally, the result:  a good working multimode QRP transceiver with 2 bands.  It should be possible to make close to medium range with it as well as DX,  even with QRP power.

And while I was building I also made a new key for this radio,  it is made out of a relay and cost nearly nothing,  looks good doesn’t it ?  hihi.

Homebrew key

The key, when in practiced hands (fingers hi), can do 50 WPM without a problem. My friend HA3HK does without blinking an eye at 40WPM with this kind of key and tells me that he can go faster if needed.  Me? I’m going it a bit slower.

Battery pack

As this radio is only using little power (0.4A in RX,  1 to 2A in TX depending the power you set it) I thought,  let’s make a battery pack for the radio.

The first plan was installing it in the box.  I did not do that because the batterypack is also powerful enough to feed my KX2 and other QRP transceivers. Since I can use it with all of them, a loose battery works out better for me.

I started with an old laptop which had a broken screen and some other malfunctions,  but still had a good battery,  although I needed the battery connector of course.  A piece of wood to mount the connector on was my next goal.  And since I still have another laptop using the same batteries, I can charge the battery without problems.  Simple, but good and it weighs much less than a gel cell battery.

The battery provides me with 12.5V and some 5Ah.  Enough to last for hours on RX and for sure good enough to activate 2 SOTA sites in one day.   It doesn’t look great but works great– that is what matters and to test it was more then good.  Next will be getting the battery pack in a nice box.  Better to re-use stuff than throwing it away I’m thinking.

I need to do something about the cover of the OLED display,  there is still some work there to make it look nicer.

Some video can be seen on YouTube :

Finallym I’d like to thank you all for reading my articles about the DB4020. I had big fun soldering, tinkering with the box, making the key, and batteryholder/batterypack.  My Hungarian friend HA3HK told me it looks a bit like a spy radio. …. ..

I also include one more time the link where you’ll find this kit :

73 TU ee



Thank you so much, Frank. No doubt, you had a lot of fun putting this excellent little kit together.

Implementing a filter switch was a fantastic idea and, obviously, not terribly difficult to do.

Based on the videos, the DB4020 has a low noise floor and very good receiver characteristics. I’m impressed that the CW portion of the radios has so many features as well, such as a memory keyer and beacon mode.

I also love how you reused that 5Ah laptop battery! I think that could almost give you a full day of SOTA activations at those consumption levels!

Thanks again for sharing this with us, Frank! We look forward to your future articles!

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