Saturday, July 12, 2025

(tr)uSDX

 So many things have been written about this little radio. I bought one a while ago. The goal is to bring it with me on vacation. It is not as big and heavy as my FT817 (compared!). It doesn't cover all bands but at the end...what do you need?

I can write a lot of things on how to make a setup. Various firmwares. What you can or cannot do with this radio. But I don't. One thing is for shure: don't have too high expectations. It is a very low priced shortwave transceiver that does what it does. You can certainly make contacts but you need patience.

Advantage is that you can do CW, SSB and digimode. You don't need a external mike, it is already inside. You don't need a digimodem, only a USB cable is enough. 

I don't want to be surprised when on my vacation address so I wanted to be shure everything works as it should be. When you buy this radio it has standard firmware in it. You can upload two types of firmware to the radio. The standard and the beta. Each has it's own features. You need the beta version (2.00x) to work digimodes with a single USB cable.

Actually updating the radio with firmware was a breeze. It was easy. Setting up the radio takes some patience and practice but can be done with some tinkering. Digimode connection takes some tinkering as well. Probably you need to assign another COM port number to the port that connects the radio. And in WSJT-X or JTDX you need to set polling rate at 80 seconds because the CAT connection is interfering with the virtual audio. You can find everything you need on this on DL2MAN's (tr)uSDX homepage. It takes some time but it can be done.

First of all I wanted to know if my signal has been received on CW. At first I transmitted CQ TEST PE4BAS K with my paddle. Nothing seen... even not after a few times. From my own experience I know how bad software CW decoders decode human made CW. So I programmed the same text in the internal auto keyer. After 3 times transmitting the same text I was spotted on RBN.


Next was SSB. You can read everywhere that SSB modulation is a thing with this little radio. Although you see a lot of YT videos from people that actually make SSB contacts. I made a recording with my IC-7300 and discovered that best modulation can be made talking reasonable loud about 10cm in front of the internal mike. 


Now, digital modes with my experimental 3 band halo. I was really surprised how easy it was to make contacts with only 4W from this little radio. It was really a matter of calling a few times and 2 or 3 stations were calling me back at the same time. I'm not shure but I have the impression that JTDX receives a lot more as the WSJT-X software with this rig.











Digimode test with the (tr)uSDX. ODX 15714km. 



You can be heard. But can you make contacts? Luckily the IARU contest is on. So I set a goal to work a SSB and CW station on both 20m and 40m. The antenna is an endfed which is the most used antenna on portable operations. I might bring my magloop on vacation but am not shure about this. With the endfed I can only transmit on 20/40m. I don't know what to expect on vacation so I decided to hang the endfed from gutter to gutter, about 3m above the ground. The worst antenna setup you can image :-). I was operating outside behind the house, my shack is upstairs (the 2 windows). At first I tested SWR. It was reasonable on 20m 1:1,5. On 40m it was reasonable till 7100 KHz. Unfortunately my earbuds fell and one of the earpieces broke. Ah well, this will happen on vacation as well. With this setup I worked RW3DU on 20 SSB, 9A0HQ on 20 CW, OE0HQ on 40 SSB and II4HQ on 40 CW. Yes, it works well.





My test operating position. Need a longer power supply cord because you need to hold the radio near your mouth for SSB. I also ordered a BNC to PL connector. The one I use now is, BNC to N to PL which makes it long and heavy.


This is probably what I bring with me. (tr)uSDX, battery with charger, minipaddle with retractable cord, compass, USB cable microUSB for digimode, USB cable for iphone charging, dummyload optional.

Friday, July 11, 2025

Tuner maintenance

 My Palstar tuner had a broken lightbulb for quite a while. I was a little irritated that it wouldn't turn on so I decided to change the original light for a green LED I had in my junkbox. Since I had to open the tuner also cleaned the interior and the coil/coil wheel/wheel shaft. All parts were certainly very dirty and I had to clean everything multiple times.

The interior after cleaning.
The wheel that makes contact with the coil was almost black inside. Don\t know what causes this?

LED install with a 2K VR.

Original lightbulb old skool. I had to magnify to see the break.

At first the LED was too bright. I was glad I installed a VR to dim the light.




Does anyone have a good idea to refurbish to lettering around the antennaswitch? It comes off unfortunately. It already did after a year or so. If I knew this would happen I had certainly made precautions and would protect it.

Monday, June 30, 2025

My quest to learn CW (19)

 


I don't do much with lessons anymore. The focus is to do plain text training every day. At the moment I train with 25/18 wpm. I can't get everything but I read that that is not important. You just go on with the next word or letter and don't think about what you missed. I think I slowly get it.

I don't make much CW QSOs right now. I don't have time to be in the shack in front of the radio. Besides that it is way too hot there. CWops helps me to go on to the next level. But at this moment I stopped the homework. I will pick it up later.

Wednesday, June 25, 2025

Connecting a straight key

 First time ever I connected my straight key. A Tsjech military key. I think a lot of amateurs have these keys as you can find them on many radio markets. I found a dutch site with description which mentions it is a WW2 key. But the key is way to new for a WW2 key. I found another site in the USA which mentions it is made in the 1950s. Nice to know that PRIJEM means RX and VISILANI means TX. This key has a switch in the cover which switches the key off when it is open. It also has a separate switch which turns on when the knob is pulled up. That is used to switch the original transceiver in RX. 

See the 2 contacts in the cover.

I wanted to solder a female 3,5mm connector to the wire. But the wire is probabely made from stainless steel. You can't solder it. 



Inside the key. The second contact is visible (red wires) those are not connected.



Decided to completely remove the cable. You see the strange kind of wire that was used. It probabely was made to last but not really usable for hamradio I think. Although the American website I previously mentioned showed how to connect an alternative way I think the long cable is not really handy in my shack. So this is what I did:


This is how it is connected to my radio now. Just a female connector and no long wire from the key.

And this is the result in the end:


Not bad I think for a first time straight key keying...


Tuesday, June 24, 2025

New QSL cards arrived from Ukraine

 I ordered new QSL cards from Gennady UX5UO at the 4th of this month. Gennady wrote that it could be 5 weeks before I get them. But the package with a 1000 cards has been received today.


Packed in brown packaging paper and in a sheet with test prints from other QSL cards. Everything was fitted in a carton box. Excellent!



It is remarkable that I received this in only 20 days from a country that is unfortunately in war. Luckily Gennady is still in bussiness. And I can recommend him for your paper QSL prints and design.


Now a huge task awaits. I've been waiting too long replying to incoming cards. Other things took my time. Those who are waiting for so long will get my new QSL card via bureau as soon as possible.


Friday, June 20, 2025

NTCQP (QSO party)

   My first effort in participating in this QSO party. The exchange: RST report, name and NTC number. This is more difficult as a contest exchange. I noticed that participating stations also exchanged some friendly text which I not always understood. I first listened to PA3HEB to get his name and NTC number in advance. It took me about 30 minutes before I got it. Not his fault but my inability. The code just goes too fast for me. And on air it always sounds different compared to a training program like LCWO. As backup I had an internet chat open with Andre PA5OES/PA6F who was also participating. It helped a lot discussing what we heard. In the end I worked PA3HEB, PA6F and PA3EEG. Hopefully I get better next time since it is actually an hour with a lot of CW fun!

Wednesday, June 18, 2025

Homemade Arduino VBand adaptor

Original VBand adaptor

 After my experiment with a old computermouse as USB adaptor for a CW key I wanted something better. Actually I found a website that gave a description af a homemade VBand adaptor made with a Arduino board. A project from OZ1JHM who gave detailed descriptions of the board needed and the connections that had to be made to the morse key/paddle. However it was not clear to me how an Arduino worked and how to upload a script. I wrote him an e-mail but never got any reply unfortunatly. Discouraged I decided to order an original VBand adaptor at Ham Radio Solutions in the US. That was months ago! It first went to the wrong country and showed up at the Israeli customs. I wrote David W6DS at HRS and he posted a second VBand adaptor to me. That was on May 9th. On the 19th of May it showed up at the Dutch customs but was still there till a few days ago. At the 14th of June it showed up in Queens NY? Back in the USA. I have no hope that the adaptor will ever arrive at my home.

So, a new search begun. I found another site from KD8RTT. It showed a similar DIY adaptor with an Arduino board as OZ1JHM's project. I wrote Tony an e-mail asking for info on the Arduino and how to get his sketch file into the board. He kindly wrote me an e-mail with an answer. So I ordered the Arduino and a cheap audio splitter cable for the connectors. Why the splitter cable? Well a splitter cable is way cheaper as separate 3,5mm jackplugs.


For those looking for the info how to with the Arduino:

Software download: https://www.arduino.cc/en/software

Online starting guide: https://docs.arduino.cc/learn/starting-guide/the-arduino-software-ide/

I didn't get the "blink" sketch to work (description in the guide, sketch used as test). So I was afraid this would be a unsuccessful project again. But after uploading the sketch from Tony it is working well now.


VBand adaptor so far.  I need to make a cover from something. I think the LEDs are very bright. Don't know if it is possible to switch them off? But if they are covered it will be allright. I already tested the adaptor on VBand and it responds very well.

Thursday, June 12, 2025

Morse Invaders Fun

 


Have a lot of fun with the CW game Morse Invaders lately. You can find it here:

https://morseinvaders.com/

You actually need a Vband or Vail CW adaptor to connect your morsekey or paddle to the computer and play this game. I ordered a Vband adaptor a few months ago but till today have received nothing yet. 

But an alternative is using straight key mode and use the CTRL key on your keyboard. So far, after a few tries, 132 is my best score. Can you do better?

18-June-2025: Having fun. Now with key on the homemade Vband adaptor I managed to score 192.

19-June-2025:


Improved my score with 8 points. Lot's of fun. I think I try with the Begali next time. The small paddle is a bit limited.

Wednesday, June 4, 2025

#6m propagation east coast USA

 Strong signals from the USA/Canada last evening. Had to go QRT around midnight, at that moment there was still strong propagation going on. 


I made a few contacts on FT8 and FT4. Had limited time. Both 50.313 and 50.323 were crowded. Best option was FT4 actually. Didn't have time to listen CW/SSB this time.

Tuesday, June 3, 2025

#6m Zambia worked

 


Another new one on 6m worked. Heard/saw him before a few times. This time I was lucky!

Saturday, May 31, 2025

My quest to learn CW (18)

 I'm trying to focus on the things I can do with CW. I might not be able to decode everything but it is possible to make a simple QSO. 

Some stats from LCWO:


Yes, I still learn with LCWO but it is part of the homework from CWops this time. I finished the fundamental homework assignments and now continue with the intermediate practice instructions and homework assignments (V2.1) from the CWops site. I keep track of my own homework writing my progress in a spreadsheet.


So far I found the fundamental assignments not that difficult. But intermediate takes more. A challenge for me, I like that. I try to learn ICR with LCWO and am now at a speed of 25/15 wpm which is the limit at this moment. 


I did a visit to the radiorally in Beetsterzwaag together with my colleague PD8HW. One of the last large radio related markets here in the northern part of the Netherlands. Lots of old and new stuff to see and buy. Lots of people I know from both hamradio and the 11m scene. One of them, PF5T Frank, was also a fanatic CW ham but keeps quiet at the moment. Hopefully he finds the time to do some CW in the future. At least we had a friendly talk, it is always nice to see known people that you normally only hear via radio.
I only bought some connectors this time and a small passive receive loop for medium wave receive. Actually the food and drinks have cost me more. The fun thing was that there was a display with Begali keys. I had the opportunity to test the HST, Expedition and Adventure paddles. I really liked the Begali Expedition paddle but unfortunatly the price it far beyond my budget. Luckily I already have a fine Begali Simplex Basic key that does very well.

Tuesday, May 27, 2025

Goodbye old equipment...

PE4BAS shack 2006/2007
 

 Can your imagine in 2006 touchscreen was still something that was just in development. Yes, some computers had touchscreen. But it only worked with a special touch pencil. I had a dream about a touchscreen controlled radio. Something that would be common in the future. I already predicted that at that time. In 2006 I bought a touchscreen laptop which I used to CAT control my Icom IC-706. I have no video about it but found one photo on which this setup could be seen. These days almost all new radios have touchscreen control. A cellphone or a tablet is all touchscreen controlled. You don't even need to have a separate CAT control modem and audio modem anymore. New radios require just one USB cable to your computer controlling everything.

So, it is time to say goodbye to this old laptop after almost 20 years. It still works but it is so slow compared to todays computers. I made good use of it. It was brought with me on several trips on vacation. It did well in several contests using N1MM software. It did well on several digimodes. And it had an excellent WiFi receiver, much better as other laptops and computers I had. But now is the time to leave it and go on with new technology. You can't keep it all.


Look at the specs. This was really a good laptop computer 20 years ago. It had a separate DVD/CD-RW player with firewire connection. Included in the package was also a USB floppy for 3,5" floppy discs. I keep that because I still have some 3,5" floppy disks with ancient software. You never know...
Abandon all the old stuff is difficult at times.

Monday, May 26, 2025

CQWW WPX CW participation


I had great plans to participate in this contest and so practice my CW skills. But other chores came up and my time was consumed faster as I hoped for. I could only be on air on Sunday evening for about 2 hours. In the end I made 51 QSOs. I've only been active on 10, 15 and 20m. Interesting DX: (20m) ZM1A New Zealand, B1Z China, (15m) NF6A CA USA, 9M2J West Malaysia, ZD7BG St.Helena, YV4ABR Venezuela, (10m) CX2BR Uruquay, 5Z4A Kenya, ZD7BG St.Helena. Always nice to work DX in such a short timespan. I also met fellow blogger VE3VN Ron with strong signals on 15m. I had problems to copy numbers at high speed especially the long ones like D4DX keyed. I probably have a few numbers copied wrong. I doubt anyone cares...

At least I was active with CW and did it without the use of decoding software like I used in previous years. A huge step forward. I wish I was a bit faster in decoding. 20-25 Wpm is managable, but at higher speeds I got difficulties to copy.

Unfortunately I'm not able do make a nice overview map from my contacts anymore. DL4MFM's simple QSO analyzer map tool is off line because of higher costs of Google maps APIs. According to his site it will be back online this month. I've been searching for another QSO to map possebility. The only alternative is QSOmaps.com. This is not for free and too expensive for me as a hobbyist. There are other sites and software that can do this. Like the old V4 version of HRD and K2DSL QSO mapper. But these need coordinates which are not always available.

(Last update 27-May-2025)

Thursday, May 22, 2025

#6m Tanzania worked

 

 

First new on band this year. Propagation was very spotty, many did not see him calling. PG1C who's about 30km west of me didn't see him at all.

Monday, May 19, 2025

Netherlands Telegraphy Club


 I applied for a membership of the Netherlands Telegraphy Club. It seems to be an active club with some activities every month. Not shure if I'm ready to participate yet, but it would be a nice goal to take part in one of the activities in the future. I got membership number 284. This club is open for everyone around the world. You can find the club homepage here: https://pi4ntc.nl/

Wednesday, May 14, 2025

Are we into the Gnevyshev gap?

I notice that HF propagation lately is not as good as last year. Especially on 6m (VHF) were we had great F2 propagation at the end of 2024. Till now nothing interesting was heard (seen) on 6m, even de ES propagation is not that good. Normally HF propagation is not that good in summer or is is something else?

The Gnevyshev Gap is a phenomenon observed in the solar cycle where solar activity, such as sunspot numbers and solar flux, shows a temporary dip or lull during the peak of a solar maximum. Instead of a single peak, many solar cycles exhibit a double-peaked maximum, with a drop in activity between the two peaks—this drop is the Gnevyshev Gap, named after Soviet astronomer Mikhail Gnevyshev.

In Relation to Ham Radio (Amateur Radio):

Ham radio, especially HF (High Frequency) propagation (3 to 30 MHz), is significantly affected by solar activity because:

Higher solar activity increases ionization in the ionosphere, especially the F2 layer, which enhances long-distance HF propagation.

Solar flux index (SFI) and sunspot numbers are proxies used to estimate propagation quality.


What the Gnevyshev Gap Means for Ham Radio:

During the Gnevyshev Gap, there is often a temporary degradation in propagation conditions on HF bands, especially 10m, 12m, and 15m, which are more sensitive to solar activity.

Operators may notice a decline in DX (long-distance) opportunities during this lull, even though it's still technically within the solar maximum.

The gap can last several weeks to months, depending on the cycle.


Practical Tips for Hams:

Monitor Solar Data: Watch for dips in SFI, sunspot numbers, and MUF (maximum usable frequency) during peak years of the solar cycle.

Plan Around It: If you're aiming for DXpeditions or contests, try to schedule them during the rising or falling edges of the solar max, not the Gnevyshev Gap.

VHF/UHF not affected: This gap has little to no impact on propagation above ~30 MHz (like 6m, 2m, or 70cm).

In short, the Gnevyshev Gap is a temporary downturn in solar activity at solar max, and for ham radio, it can momentarily reduce the exceptional propagation conditions expected at the peak of the cycle.


Although this gap has little impact on VHF I think certainly F2 propagation on 6m is affected. But who am I to write that, I'm not an expert in HF/VHF propagation. However I found this interesting enough to write about.

Monday, May 5, 2025

WW2 story from (near) my QTH

Today, May 5th 2025 it is 80 years ago that the Netherlands was liberated from the occupying Germans. This is a story I wanted to write for a long time. It happened around the village I live in. Radio operators from the resistance were involved. The story is well known, but it was difficult to verify all the facts. There was a lot going on at the end of the war and around this story. I shortened it as good as possible remaining only what was going on here. 

Work goes on... 

This is a story I wanted to write for a long time. It is actually a follow up from one of my blogposts in the past. That story was the first one of three about PA0DR Dirk Rustema who was active in the resistance and a radio operator at that time. Dirk was arrested in August 1943 and brought to Germany to appear in court for his illigal activities at that time. Dirk was lucky and was the only one from a group of prisoners that was convicted to get to a penitentiary. After that happened his friend and former mechanic Albert Zuidhof (code name "Anton") took over the duties in the resistance. Since there was nothing left of the former resistance group "Zwaantje" Anton had to make new contacts. Which he eventually got with someone from the village of Blaricum (coincidence, my place of birth) in the center part of the Netherlands. He obtained a new transmitter with power supply from this contact. Some believe it could be a Paraset V, but this is a transceiver and the historic books tell us it was just a transmitter. The receiver was build with parts obtained from Philips equipment-laboratory through close friend Gerrit Bakker. This receiver had a battery supply which was needed because of the regular electricity grid failure at that time. The equipment was placed in an attic of one of the outbuildings of the pudding factory Atlanta in the city of Groningen. Unfortunately it turned out that the connection between transmitter and antenna did not work, something that was discovered by a radioamateur PA0PC Jaap van der Hul (code name "Radio-Kees")  from Hilversum. He solved the problem but things went dangerous and the resistance needed to stop their work immediately.  In the mean time the southern part of the Netherlands was already liberated at the time this all happened. 

The farm, on the background
the Eemshaven harbour. Photo made from 
the decoy towards the farm 
to show the distance Piet
had to run.
New location Uithuizermeeden

After a moment of inactivity they found another place to place the transmitter. Far away from earlier locations at a farm near Uithuizermeeden, just a few kilometers from my QTH now. This time with "Anton" as radio operator and Gerrit for technical assistance and code-duty (code and decode secret codes). The first contact with the allied forces in the liberated south part of the country was made on 4 Nov. 1944. Several successful messages were transmitted. In the winter of 1944/45 "Anton" was too busy with other duties. In the mean time Gerrit learned morsecode and was already capable of transmitting messages on his own. Through the local resistance they also got weapons to defend themselves, probably not the best idea in the end.


The duck decoy, approx 1km from the farm.


The Germans strike

At the end of January 1945 things went smootly. The new location was excellent and radio transmissions went on. They thought they could still share a lot of information in the remaining days of the war. "Radio Kees" and Piet van Dijk from Hilversum came to the farm to help, both were radio operators and technically skilled. And all went well. Till the 6th of February...after they had probably betrayed or have been located by German direction finding equipment. About 30-40 German soldiers came to surround the complete farm so no one would be able to escape. Piet, Gerrit and the farmer Bene tried to shoot themselves a way out. Piet tried to flee to a nearby duck decoy but was shot there, he died at a age of 22. Unfortunately both Gerrit and Bene were seriously injured, they were captured and questioned. They were shot later that year. In the mean time "Radio Kees" was more understanding and had the chance to burn the code book and as much equipment as he could in the woodstove. He was taken prisoner and was subjected to extraordinary torture, unfortunatly he gave a lot of info to the Germans to save his own life. He survived the war but was so exhausted that he died in 1948.

Stolperstein (memory stone) in memory of the farmer that died. On the background the farm.


Documentation:

Verzet in Groningen - ISBN9062430465

https://www.tracesofwar.nl/sights/124393/Stolperstein-Dwarsweg-1.htm

https://droog-mag.nl/2020/ag/nsf-monument.html

https://www.hilversumsnieuws.nl/reader/131534/78832/verraad-viert-hoogtij-in-boek-de-prooi-wordt-jager#p=11

https://a03.veron.nl/wp-content/uploads/2025/01/Bijlage_gevallen_radioamateurs_VERON_1949-VERON_a03.pdf

https://www.groningen4045.nl/portretten/bene-roelf-westerdijk-uithuizermeeden

https://oorlogsgravenstichting.nl/personen/170370/bene-roelf-westerdijk

https://en.wikipedia.org/wiki/Stolperstein


(Photos made by me on 22 April 2025)

Thursday, May 1, 2025

Paracette or Paraset research again

In the Netherlands we have the 80th year of freedom celebration after the second world war on the 5th of May. In honour of our freedom I have written some posts that are follow ups from posts I wrote in the past. If you like to read it, here are the links:

https://pe4bas.blogspot.com/2021/03/paraset-instruction-manual-discovery.html

https://pe4bas.blogspot.com/2021/11/paraset-instructions-new-insights.html

Paraset

The case of the "Paracette". Unknown if there was a Paraset among the 5 transmitters (receivers) that were used by the "Zwaantje" resistance group till September 1943. Known are a Soto transmitter, a Winchester transmitter, an Eton-3 transmitter, an Eton-4 transmitter and a homemade transmitter. So far I could not find anything about these. It can be that the name Paraset was not really known and instead they gave the tranceivers names so one or more of the above could be a Paraset after all.

PA3BCBs note

Unfortunately Gerard PA3BCB died last year. He was the one that rescued the WW2 Paraset instructions and gave them to me. Well you know the story, and if you don't, read the articles about it on my blog. Gerards widow brought me a note he wrote for me before he died, he was obviously busy to find out about the transmitters that had been received by the "Zwaantje" resistance group via the Sweden route. The note was about some facts he did read in the report that "Ton" van Schendel wrote after the war. This report can be found at the excellent site from Willem PH0WAW. A very nice network overview block diagram from "Zwaantje" can be found here. It contains some faults but it brought me closer to an answer.

"Ton" wrote 

I decided to read this report again and this is what I found about the "de Soto" transmitter.

It turned out that an espionage group in Delfzijl, which as it turned out later was led by "ZWAANTJE" (Dr. Oosterhuis) and which maintained an intensive traffic with England via Sweden, had received a transmitting and receiving device from England (mid-February 1943). This equipment was equipped with four crystals (a day crystal with evasive frequency and a night crystal, also with evasive frequency; the day wave was about 47 and the night wave at plus minus 85 meters)

SIS Paraset (pic from weggum.com)

Further in the report some other facts about "de Soto"

Later it turned out that the initial failure of the connection was not so much due to the low power of "DE SOTO" transmitter, but rather to the lesser ability to operate the receiver. The whole case, transmitter-receiver plus P.S.A. (power supply) was no bigger than a cigar box and could easily be carried in a briefcase. Due to the extremely complicated construction, the receiver had a fairly small tuning scale, while the range was quite large, namely from about 25 to almost 100 meters. The coordination was therefore very difficult and critical and required great skill. We have taken great pleasure in such receivers by making some belt spreading and the use of a long rod for tuning, which made it much "finer", especially when most of the receivers had to be put away as a result of the surrender order (13 May 1943).

At first I though "a cigar box"? In my opinion that is too small for a Paraset. But looking at the above photograph I'm not that sure anymore... the suitcase on the pic is very small considering the size of the handle. I don't know the size of a cigarbox at that time?  However the Paraset on the picture is believed not the exact model that was described. There were several models made, and not every model was build into a suitcase like in the picture. So what the "de Soto" transceiver looked like will remain a mystery.

In my opinion it is very likely that the other "transmitters" were in fact "transceivers". And except for the homemade transmitter(s) the transceivers with names could actually be all Parasets.

Wednesday, April 30, 2025

5252F or YX805

 No, these are not secret callsigns from spy stations. These are small LED driver ICs. Ingenious small cheap devices that feature a solar charger and a step up converter. Probably every solar light has them inside.




Totally unaware of these devices I had a broken solar light that had a good battery and good LEDs. The switch was alright but it didn't switch on. To buy a new LED driver IC is just too expensive (€0,39 + €6,95 for postage). Luckily I had another solar light with a bad battery and salvaged parts to repair our broken light. It was a matter of exchange the IC and the coil. 

 More inside info can be found here:

https://artists.scitoys.com/three_volts

If you click on the picture on the right you will have a larger one. The parts that I've exchanged are just near the second LED at the right.




We love solar lights in our garden!