Category Archives: Guest Posts

George reviews the new Tecsun PL-990

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Many thanks to SWLing Post contributor, George Joachim, who shares the following review of the Tecsun PL-990.

AS George points out, the PL-990 in the following review is not the “export” model Anon-Co will eventually offer for sale later this year. It might be nearly identical in every respect, but at time of posting Tecsun is addressing some final firmware updates the the “export” version prior to starting a full first production run. As we learn more about the various versions of the PL-990 in the wild–compare serial numbers, etc.– we will eventually sort out any nuances between versions.

George purchased this PL-990 on AliExpress and I am incredibly grateful to read his review of this model:

Review of the Tecsun PL-990

by George Joachim

Introduction

The Tecsun PL 990 is one of the three new radios offered by Tecsun and according to the news from the company these may be the last developed.

The other two radios are the Tecsun H-501 and the PL-330. The H-501 is the largest with dual speakers and the PL-990 is of a similar size to the PL-880, PL-680, PL-660 and PL-600. The PL-330 is the smallest and is similar to the PL-310ET and PL-380.

The Tecsun PL-990 is a medium sized portable multi-function radio. It has the following features:

  • Shortwave (SW)
  • Medium Wave (AM)
  • Frequency Modulation (FM)
  • SSB (LSB and USB)
  • Bluetooth connectivity (BT)
  • MP3 playback from a microSD port
  • Clock and two Timers with Alarms
  • Auto Sleep
  • powered by a single 18650 rechargeable 3.7V Lithium Ion Battery, unbranded and supplied.

The radio is a refinement of the PL-880 with styling similar to the PL-680. It is matte black with a hint of grey, finished in a quality plastic case and it is ergonomic with a good weight and feel, just like the PL-880.

Background

This is my fourth portable radio of this size. I had owned the analogue Sony ICF-7601 back in the day and then the PL-660 and PL-880. The Sony was destroyed by me doing naughty electronic experiments and both the PL-660 and PL-880 were gifted to my family members.

Having no such radio, I considered the purchase of a new PL-880. I had contacted Ms Anna from the Anon Co. in HK and she was very helpful and also mentioned that Tecsun is developing a couple of new radios, but these are not yet available. This got me interested in the PL-990 and the H-501. I had also considered the H-501, because I liked the fact that it has two speaker sets, however the radio did seem a big bulky for my needs. I have a few desktop radios, but I needed something to be on my lap or by the bedside. Usually I fiddle with these portable radios lying on my chest until I find something nice to listen to then let it play on auto sleep until it puts me to sleep. I am sure some of you guys do this too. I imagine the H-501 would be a bit big for this.

After reading articles on the SWLing Post and despite the warnings about Pilot run versions and Chinese versions, I decided to risk a purchase from AliExpress. This has been my one and only purchase on AliExpress so far.

Purchase

My radio was supplied by a company called Li Jia Shops in AliExpress. It cost a steep US$400 and US$157 DHL shipping. Totally expensive and risky in my opinion, but I am known to be reckless with my online purchases.? Besides, I wanted a new toy!

As this was my first purchase from AliExpress, I was a bit apprehensive, as I mainly use eBay. Also buying electronic items from China is a bit risky. One may end up not getting the item, or getting it after some significant delay. As you all know, electronic items exported from China is the largest electronics export operation in the world, so there is congestion in logistics and Covid-19 also adds to that. Selecting DHL to ship the item was very expensive, but I believe necessary. Waiting for an expensive electronic device for two months is a painful experience, at least from my perspective. Using DHL took a mere 12 days. The main delay originated from the shippers. They give the shipment information to DHL well in advance, but they do not actually take the item to DHL unless it suits their facilitators who they assign. The shipment shows as shipped and DHL status is ‘shipment information received’, but in reality the item is still with the shippers. Once it does actually get to DHL, then it is quite fast. Usually the shippers are located in the Shenzhen area and DHL is in Hong Kong. AliExpress will not release the payment unless the buyer confirms receipt of the item as described, so there is some safety for the buyer.

Overall, I was satisfied with the purchase and shipping process. But it was expensive and it was risky. It would be better to approach Anon Co in HK for your purchases rather than AliExpress and Bangood, but ultimately it is the buyer’s decision. For the English Export Version you must wait a bit I think.

The Export Version, the Chinese Version and the Pilot Run Version

This aspect is a bit confusing. From what I understood, and I could well be wrong, the versions are as follows:

Pilot run: this has the buttons as TIME DISPLAY and ALARM (this is also slightly cheaper on AliExpress and Banggood)
Chinese version: TIME TIMER A and TIMER B, but with Chinese manuals (what I have acquired)
Export Version: TIME TIMER A and TIMER B but with English manuals. (there may be further changes / improvements, as these units are still not available)

I am not sure about the firmware. My unit is presumably a later Chinese Version. And everything works properly as per the Firmware. The serial number of my unit indicates a possible manufacture date of July 2020, although this could be wrong.

Review

The review will be based on the different functions of the radio.

FM reception

In the UAE we are blessed with several English language FM radio stations with good music and limited advertisements. Each station caters to particular tastes, such as 90s music, modern and classic hits. Reproduction was crisp and in full bodied stereo. The speaker is powerful and not unlike the speaker of the PL-880.

MW reception

I do not usually listen to AM or MW. However, the radio does a good job receiving these stations with a deep sound and minimal crackling.

SW reception

Shortwave is still out there folks, although its variety and abundance is greatly reduced. I do receive quite a few broadcasts using the telescopic antenna. Activity is concentrated around the 16m band, the 31m band and the 49m band, although occasional broadcasts can also be found in the 22m, 19m and 41m bands. The SYNC function holds on to weak broadcasts and makes them intelligible. I am sure that the Radio would do a commendable job if one could use a time machine to take it back to the SW hay-days of the 80s and 90s. I wonder if they have any time machines up for sale in AliExpress? 🙂

SSB Reception

Right out of the box I was able to fine tune into 14,182.10 kHz on the USB and hear HAMS ‘doing their thang’. It was excellent and far better than what similar attempts resulted in my previous Tecsun radios. I do think that Tecsun has improved the SSB reception with this receiver. I am not a very capable SSB chaser, but if there is something SSB out there, the PL-990 should able to pull it in. One needs to know where and when to tune and luck also plays a role.

LW Reception

Yes it is there, but no, I have never heard anything in there using the PL-990 and all my previous radios. I do wonder if submarines transmit in the LW band? I don’t know.

MP3 Playback

A lot of listeners are not interested in MP3 listening, but I am. Especially with SW being so sparse nowadays. MP3 was a feature missed from previous Tecsun radios. I enjoy compiling a list of favourite tracks and listening to them, while engaged in a barbecue or in car maintenance or cleaning. I am also a train modeler and like to listen to MP3s while running my trains. Tecsun has even supplied a Sandisk micro SD card of 16GB with various Chinese and international tracks, which I think was nice of them.

Bluetooth

There is no Bluetooth button, but by pressing the RADIO/MP3 button an indication will come on the display as BT. The radio can then be conveniently paired with a mobile phone to transfer the audio from a you tube clip or similar to the radio, although I wouldn’t see the need for that. I am not sure if files can be transferred to the radio this way, I believe the function is only for audio playback.

Presentation and packaging

Much like the PL-880, the radio comes superbly packaged. The cardboard box functions as a glossy display of the radio and its features. Inside there are foam holders and there is a sturdy grey plastic toolbox case. In the toolbox case there is the radio, within a nylon bag inside its light brown faux leather pouch. The radio as well as the pouch have a carrying strap. In the toolbox there is a black foam case that contains:

  • A blue 18650 3.7 V Lithium Ion Battery
  • A long wire antenna in its real
  • A short(ish) charging cable
  • A UK style plug adaptor
  • A Chinese style charger with 2 USB outputs
  • A Chinese language operation manual
  • A Poster containing the map of the world and country Radio codes
  • On the other side of the Poster is a detailed view of the PL-990 with illustrations in Chinese

Batteries

The radio uses one Li-Ion type 18650 3.7V battery. The included type is a blue generic unbranded type, I would have preferred a Tecsun-branded battery. I have a couple of vape equipment batteries –Golisi S30, which I believe are superior to the unbranded battery. (No, I am not a Vaper).

Concluding Remarks

The latest Tecsun offering is a great conclusion to their series of multi-function portable radios. It offers some advantages over the PL-880, such as:

  • Styling
  • MP3
  • Much improved SSB reception
  • Superb FM reproduction
  • Bluetooth

Apart from the above I don’t see a compelling reason to acquire the radio unless, SSB or MP3 is important for you. Or like me, you just must have the latest.

Score

Style: 90%
FM: 100%
SW: 90% SYNC available
SSB: 95%
MW: 85%
LW: 80%
Battery Life: 70% for the provided battery 8/10 for externally sourced batteries
Display: 70% (the display is good, but it hasn’t really changed from previous displays)
Buttons: 85% Sturdy and precise, no wobbly buttons here.
Dials: 90% hard and precise with excellent indentations
Ports: 90% strong a tight female ports with protection plugs
Packaging: 95% anything you could wish for.
Documentation: 100% for Chinese speakers
Antenna: 60% normal telescopic antenna, should be a bit more shiny IMO.
Stability: 70% Stands well and has the rear bracket as the PL-880, however, would be easy to snap if pushed.
Sensitivity: 95% if it is there it will receive it and improve the signal over listening time.

Overall Review Score:
85.3%

Final thoughts:
Go get one, if you must, but better wait for the full export version.

George Joachim
11 AUG 2020

Many thanks, George, for sharing your review of the PL-990!

So far, the PL-990 sounds like it has iterative improvements over the PL-880 which is, I suppose, what I would expect. The PL-880 is a great portable, so I believe even minor performance upgrades–especially in terms of synchronous detection–could be very beneficial to some SWLs.  And thanks for taking the deep-dive and grabbing one of the models on AliExpress! It’ll be interesting to compare notes once the “export” PL-990 is released.

Jorge’s Portable YouLoop Antenna Frame

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Many thanks to SWLing Post contributor, Jorge Garzón (EB7EFA · EA1036 SWL), who shares the following guest post which was originally published on his @IberiaDX blog:

BricoDX: A YouLoop portable frame

by Jorge Garzón (EB7EFA · EA1036 SWL)

Youloop ‘in the forest’

One of the aerials I wanted to test was the Youssef Loop (YouLoop). I own a good passive loop antenna made by Tecsun (AN-200) but this is a mini one to use with portable receivers. A video showing the test of this ‘mini-loop’ can be seen in my YouTube channel.

My main loop for serious DXing is the Wellbrook 1530LN, but this is an active loop that easily beats any other passive ones. It’s close to be the perfect loop for me as I live in a rural valley with low noise level in the bands so I enjoy every minute of my listening sessions. However I wanted to test this newcomer passive loop, but wasn’t satisfied just hanging it from a pine tree branch, so I decided to bring about my DIY YouLoop portable frame project.

So I had to find something to get a rigid (but light) support for the loop itself allowing an easy rotation to achieve deep nulls. So… what could I built?

Fiberglass tubes, hooks and crossed arms.

I am professionally involved in the heritage and communication sector, so was easy for me to refit some dismissed display rolls where I found a 1,5 m thin supporting tube made in fiberglass that suited my needs. I cut a piece of 120 cm and then split it into 2x60cm, tightening both in the middle with a fine bolt. I placed two plastic hooks up and down of the vertical tube to hold both Youloop modules. The horizontal arm was lengthened with two bamboo meat skewers firmly inserted into the tube, allowing to slide onto it. Two small holes in the bamboo pieces were good enough to secure the cable with a short wire. All this was well fixed with clamps and vulcanized tape to an extra piece of vertical tube.

Bamboo meat skewer and tied cable.

Finally all this was inserted into a thicker aluminium tube and then into a wider one in order to fit everything into the tripod hole and then get a smooth and efficient rotation of the antenna. As a base I re-fitted an old heavy metallic tripod manufactured by Manfrotto (Italy) that I used it often for birdwatching day trips. I gave back an unexpected new life for this piece of metal, always in the field close to Nature!

The whole assembly can be easily transported in the car. Aluminium tubes slide one into the other, being rapidly detachable from the loop itself. This is a cheap and DIY project to get the maximum of this surprising and low noise passive loop.

This aerial gives its best performance when used in the field. There, QRM levels are low or non existent at all. It is a must to rotate it easily and then get sharp nulls. SMA connector nuts must be well tightened as they tend to loosen easily, but beware to force them as an extra twisting could damage inner connections.

This is the first post of a series called «BricoDX» where I will show how to refit or build accessories to get inexpensive and practical DIY projects for our listening sessions.

Many thanks for sharing your article with us, Jorge! That’s a brilliant loop support.

Readers: check out more of Jorge’s articles on his blog, @IberiaDX. Also check out his YouTube channel where he posts videos.

K9ZDK: Return of a Silent Key

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Many thanks to SWLing Post contributor, Dan Van Hoy (VR2HF), who writes:

It was one of the most sublime moments in my 55+ years in radio. Almost every night I listen to shortwave station, KNLS in Anchor Point, Alaska, from my home in Hong Kong. KNLS broadcasts to Asia and the Pacific in English, Russian and Mandarin. The English broadcast is an amazing mix of secular and Christian music and topics, science, current affairs and more. It has something for both the seeker and the saint and is one of the most informative and entertaining shows on radio.

On this particular Monday evening, August 3, 2020, I tuned in late to the English broadcast from KNLS at 1000 UTC, but went on to listen to the remainder of the show. To my complete surprise as the show closed I heard “73 de K9ZDK” in Morse code and quickly wrote down that callsign. I assumed it was the engineer on duty, obviously a ham, having a little on-air fun with a big transmitter and antenna.

A few minutes later, I also heard “CQ de K9ZDK” at the beginning of the Russian program at 1100 UTC. So, I looked up K9ZDK on QRZ.com and found it was Zavier, a young ham who had become a silent key in June of 2019.

Zavier Klingensmith (K9ZDK) Silent Key

A little more online sleuthing and a phone call later revealed that his father, Thomas, KL0K, was at the controls of KNLS that night sending Zavier’s final CQ and 73 on this planet with at least 1 million watts of power (ERP: 100KW TX + 10dBd TCI curtain array) all around Asia and the Pacific. His call on CW was heard on every English, Russian and Mandarin show that evening over 16 hours of broadcasts (two Continental 100 KW transmitters). Wow!

In Zavier’s memory, Thomas has created a DIY kit for an Iambic Keyer and is offering it for FREE (though you might want to send some $$ for his production and mailing costs…my suggestion) to anyone who asks. Details can be found at Thomas’, KL0K, QRZ page. Maybe one of the first things you can send when your keyer is completed is,”K9ZDK de YOUR CALL, 73 OM!”

Thomas, our thoughts and prayers go out to you and your family. Thanks for the amazing on-air tribute to Zavier. I suspect he was listening with a big, big smile!

Dan VR2HF, Hong Kong
(K7DAN, USA)

Guest Post: What is FM Lightning Scatter DX?

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Photo by Olivier Lance on Unsplash

Many thanks to SWLing Post contributor, Bruce Atchison, who shares the following guest post:

What is Lightning Scatter DX?

by Bruce Atchison (VE6XTC)

Believe it or not, it’s possible to receive distant FM stations during a thunder storm. While lightning makes it difficult to hear AM and shortwave broadcasts, its crackles aren’t as evident on the 88 MHz to 108 MHz band.

When lightning strikes, it temporarily ionizes the air around it. Radio signals are reflected by the charged gasses and come back down to earth.

From my experience with this kind of DX, the signal became noticeably stronger during lightning strikes. This effect lasted for a second, then the signal level dropped to its former strength.

While a thunder storm raged overhead on July 7th, I used my CC Skywave SSB radio to check out the FM band. Instead of hearing E-skip as I had hoped, I found that tropo-like conditions reflected stations down to my home. I heard signals from a hundred miles away or further.

As just one example, I found a low-power station with the call letters CKSS on 88.1MHZ. They call themselves 88.1 The One. Find out more about this station at the http://www.881theone.ca/ link. It’s located in the town of Stony Plain, Alberta. This station plays country music and airs local news events.

At a guess, I’d say the transmitter is about 120 miles from my QTH in Radway. It normally doesn’t come in at all. The signal strength varied too, showing that it wasn’t a local.

In my instance of catching CKSS’s signal, a form of tropo ducting was also present. Rain can produce reflections of signals but it’s much more pronounced in the UHF and microwave bands.

When a thunder storm is ruining AM and shortwave reception, try DXing the FM band. You’ll be surprised at what occasionally comes in.

For further information on weather-related DX, check William R. Hepburn’s article.

To see a demonstration of lightning scatter on amateur TV, watch the
following video:

To hear what FM lightning scatter sounds like, watch this video:

Thank you for sharing this guest post Bruce. I’ll be the first to admit that I’ve never tried to hear lightening scatter DX, but I will certainly give it a go.  This time of year, we’ve numerous thunderstorms in the afternoon and evening, so I’ll certainly have the opportunity!

Post readers: Have you ever caught FM DX off of Lightening Scatter? Please comment!

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

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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 :

https://www.qrphamradiokits.com/

73 TU ee

Frank

ON6UU

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!

W9IMS: A delayed start for the Indianapolis Motor Speedway special event station 

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Many thanks to SWLing Post contributor, Brian D. Smith (W9IND), who shares the following announcement:

W9IMS: A delayed start for the Indianapolis Motor Speedway special event station

by Brian D. Smith, W9IND

It’s a late start for auto racing at the Indianapolis Motor Speedway, as well as the amateur radio station that honors this century-old tradition … but the show must go on!

And this week it will, as special event station W9IMS returns to the airwaves from now through Sunday to offer radio hobbyists a fresh opportunity to collect more “wallpaper”: Two vivid racing-themed QSL cards and the popular certificate known as the Checkered Flag Award.

The 2020 certificate will be easier than ever to earn. Normally the Speedway’s three major races take place on three different weekends, but this year, because of Covid-19 concerns, they’ll be consolidated into two. Accordingly, hams and SWLs will be required to contact or tune in W9IMS during only two race weeks – the current one, which continues through Sunday, July 5; and Aug. 17-23, which ends on the day of the venerable Indianapolis 500.

Even if you succeed in snaring W9IMS only once, you can still send off for the corresponding QSL card. All certificate and QSL designs are new each year.

The coming Independence Day weekend will feature an unprecedented racing doubleheader, with the IndyCar Grand Prix and the NASCAR Brickyard 400 slated for Saturday and Sunday, respectively. Consequently, the first W9IMS QSL of 2020 will be a full-color, four-sided card portraying images from both races.

So where do you find W9IMS? The station will stick to three bands, 20, 40 and 80 meters, and may appear at any time of day or night from now through Sunday.

However, the best bet is to catch the station during prime time – 2200 through 0200 UTC on weeknights (6 to 10 p.m. Indy time). W9IMS operators also plan to activate 20 meters during daytime hours, often between 8 a.m. and 2 p.m. (1200-1800 UTC); and will cover the various bands all weekend starting at 10 a.m. (1400 UTC) daily.

If you still haven’t caught W9IMS by the time Sunday evening arrives in Indianapolis, operators commonly conduct their own happy hour – working stations in rapid contesting style – right up to midnight (0400 UTC Monday).

Here are a couple of hints for tracking down the station during special event weeks:

  1. Go to the W9IMS web page (www.w9ims.org), find the “2020 Operating Schedule” heading, and click on the link to “Grand Prix & Brickyard” or “Indianapolis 500.” Although some W9IMS operators get on the air at unscheduled times, you’ll have your best luck looking for the station during the hours and bands reserved with a name and a callsign.
  2. Check DX Summit (www.dxsummit.fi) for spots that identify the current frequency (or frequencies) of W9IMS, if any. And if you type “W9IMS” in the search box, you can customize it to show reports for only that station.

For additional details, consult the W9IMS web page. Feel free to submit both of your 2020 QSL card and certificate requests in the same envelope, and if you don’t have your own QSL card, a printout of your W9IMS contacts or reception reports will suffice.

Building the EA3GCY DB4020 Dual-band 40 and 20M QRP SSB Transceiver Kit (Part 1)

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Many thanks to SWLing Post contributor, Frank (ON6UU), who shares the following guest post:

Building EA3GCY’s DB4020 QRP Transceiver kit

by Frank Lagaet (ON6UU)

In May, I discovered via a newsletter that a new kit was available from Javier EA3GCY in Spain.  I was immediately sold as this was a kit from my favourite kit producer and it has 2 bands–it will also be able to do CW and there also will be a CW filter.

After building 2 MFT’s from Javier which work without problems, I needed to have the DB4020.  The MFT’s are for 20 and 40 mtrs and do DSB (double side band).  I did put them in a not-so-graceful box but they do what they are intended for which is QRP phone (SSB).   They came together without problems so I expected the same for the DB4020–I knew for sure when I saw the board:  all through-hole components (except for some capacitors which are factory soldered) and a lot of space on the board.   The board has been silk-screened with clear indications on where all components have to come and the manual has very clear instructions where each component has to be soldered with referral to a quadrant.  The manual provides a 252 quadrant page so it is a piece of cake to find where each piece goes.

What do you get?

Javier provides you with all components which need to be installed on the board and, of course, the kit board.  The components come in small marked plastic bags and all is well-wrapped up in bubble wrap.  The board is wrapped separately and that is put together with the component wrap which is then again wrapped up in bubble plastic.  All goes into an envelope.  Very well packed I must say.

Here’s a picture of the bags with components:

The silk-screened board:

I started with the resistors since that’s the easiest way. After that, I did the capacitors.  I like to solder in all flat components first, so next were the diodes and IC sockets followed by the elco’s.  The transistors were next together with all relays.  As you solder in the transistors one also has to mount the cooling heatsinks,  these cooling sinks are high and are ideal to protect the coils one has to make,  they also protect the polystyrene caps (which I always find vulnerable) when the board is upside down.

Many kit builders are afraid of winding the toroids in kits–don’t be!  It is easy.  Just take your time and follow the instructions given by Javier in the construction manual.  In this kit the builder has to wind 8 toroids:  6 are a single wire which goes through the toroid body,  1 is a toroid with 2 different windings, and 1 has a twisted pair which goes through the final toroid.  Be sure to measure the wire you need per toroid as instructed in the manual.  Javier gives some spare, so you can be sure.  You will also see that on next picture where the legs of the toroids have not been trimmed yet.  Once done I still had some centimetres of wire leftover.

Picture of the toroids ready to be soldered in:

Finally all other parts and pin headers went in,  jumpers were immediately put on where needed.

As I’m using a military-grade plastic box, I have to break-out some components like the display,  tuning encoder,  volume and rx control from the board.  I also have put an on/off switch on the box and already have the CW KEY connector ready installed. I also installed a loudspeaker in the box.  The SI5351 board and the Ardiuno Nano are the final components which go into the board after installing all wires.

Picture of the board:

I intend to attach a CW paddle to the box made out of a relay.  A HWEF tuner (from EA3GCY) which I was planning to incorporate in the box is I think a bit overkill. That HWEF tuner is already in a nice little box and would be a pity to dismantle,  also I’m running out of space in the box…  Maybe I can fit in a 9-1unun which would then give me good results on both bands…?

Maybe I will install a battery pack in the same box.

The box with board installed:

The box completed front side:

Mind you,  it still needs some additional switches for the CW part of the transceiver.

73
Frank (ON6UU)

Video

Brilliant, Frank! I really appreciate the video as well–sounds like the kit produces smooth audio and should serve you well. No doubt, that military box enclosure will survive even the roughest field conditions!

Click here to check out the DB4020 kit at EA3GCY’s store.