Be patient and you’ll see dream come (tr)uSDX. My most complicated kit, so far.
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- čas přidán 8. 10. 2022
- I had unexpected challenges in building and troubleshooting the (tr)uSDX Ham Radio transceiver kit. In general, this QRP radio is becoming very popular among the QRP radio enthusiasts. It is fully SDR design yet simple and ingenious schematics. It’s roots and prototype go back to the QCX radio from the QRPLabs. At the moment, it’s a unique multi-band design licensed under open-source rules by two hams - Manuel, DL2MAN and Guido, PE1NNZ. The license gives a right to anybody to produce and sell commercially this radio with the only condition it must be approved by the authors and produced with no changes to the original schematics and PCB’s. At the moment (October 2022) there is one kit maker from China approved good to make and sell the (tr)uSDX kits. Another company from Romania was producing the kits for a short time but is not now , except of selling out some stock items. All information on where to buy and explanations regarding the relations with the Romanian company is on the Manuel’s website dl2man.de , as well as all the technical information about the assembly and tuning.
My Chinese kit is functioning now but it took some time to figure out what was wrong and how to fix it. Some issues I left unfixed with a hope of good advice from you, friends. Please leave your comments in the comments section. I also have the Romanian kit which turns to have the dead MCU on it. I’m planning to replace the Atmega328P in this board, but not in today’s, in coming videos. So, please consider subscribing, if interested!
My desoldering tools similar to these (affiliate links, I earn small commission from the resulting purchases with no extra cost to you):
-desoldering iron with suction pump
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- just the suction pump, the cheaper alternative
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73! Linas LY2H - Jak na to + styl
I learned so much building this kit, even how to program boot loaders! I feel like a pro now that I have an awesome little qrp radio 💪 working.
Wow, you know so much! Immediate sub.
Good on you, Linas, for being persistent tracking down the problems and repairing them!
Thanks Thomas! Troubleshooting is a part of fun in our hobby :) I put this in the video hoping my story might be useful for someone else... 73! Linas LY2H
I once made a QSO just the way you did, just on the build in key.
Actualy the less power i use, the more the DX (dunno why)
Once i even had a pileup on 40M-CW while driving on the motorway. (Kids don't do that at home !)
painfull to watch , but cool , and neet you made kit and made contact
I have notice on mine occasionally the swr cct will read off and a quick fix is to put your finger on the swr cct and then it magically reads correct. A few people are now calling this the magic finger fix for the swr cct.
There is also a thread on the form talking about an experiment with changing some resistor and capacitor values of the swr cct that have been able to fix it.
Thanks for reminder Randal! Yes, I’ve red all the interesting threads in the groups.io regarding the magic finger! Sounds very scientific , but hasn’t worked for me, unfortunately :). I have yet to try the resistor trick. 73! Linas LY2H
I like the “pumpkin” case print on your Trusdx, complete with the green stem.
Thanks! The case print files are available at dl2man.de. 73! Linas LY2H
Linus the 12V cracked and intermittent is enough to take out the RF Transmitter, Pins on the Microprocessor and all the other stuff you got into. Likely the board had failed or was about to at Reflow and when the header was soldered it that was it! Anyway I order work boards 100% tested with a flying probe at the board fab.
Thanks for this info John! I'd like them to but I'm not sure I know how could I get DL2MAN-approved Chinese kits seller testing the boards with a flying probe at the board fab :). 73! Linas LY2H
Hi Linus, my trick for desoldering is to resolder the joint with new solder this seems to make it a lot easier (ie less time heating the joint?. I then use a soldarpullt solder sucker. They have huge suction. Anyway I share your pain re cracked tracks. Keep smiling.
Thanks for sharing the trick! 73! Linas LY2H
One more thing see if you can get solder with 2% silver as well as lead and tin. This stuff flows beautifully. I have not been able to master the unleaded stuff.
@@chrisherd991 Thanks agn Chris. I'll check this out. For replacing chips, I have and use some special solder which stays melted longer than the normal one when applied on the contacts and this feature allows for comfortable removal of multileg chips, like processors etc. But it's best for the SMD packages. 73! Linas LY2H
Good video👍 LINAS you have much more patience than I do. I am not sure what I would have done. 73. KV5P
This rig is challenge and fun in one box. I just ordered a Retevis mic as an external mic. By the way: DL2MAN’s operator name is Manuel…😊 73 de Chris DL1GKC
Thanks Chris! Yes, I know Manuel's name and it's pronounced ok in the video :) . My typo in that comment, sorry! Good luck with your Retevis mic! 73! Linas LY2H
I literally just came home from a park where my trusdx failed to transmit (0W output, SWR 9.9) all of the sudden, when I plugged it in. I just had the oldest idea in the book and did a reset. And it’s working again😅
Thanks for your videos, always a pleasure to watch. 73!
Thanks Simon , and lucky you! I've re-flashed twice the whole firmware with no avail :) 73! Linas LY2H
Nice video Linas ! Apprciate your description and knowhow, shure many can learn from this. I have two truSDX, high and low bands kits, have not started building yet. I had an idea of using one Contr pcb and make the band filter pcb’s swappable, to cover all bands. May not be a good idea, after looking at your video though !
73 de LA8OW
Thanks Arvid! I think, swapable bands might be a nice idea with the condition you swap the entire RF boards. The menu item in the firmware allows for choosing which RF board is connected. If I remember correctly, Adam K6ARK, has implemented this idea and he's even developed a modified 3D case for this! Good Luck! 73! Linas LY2H
G’day Linas I had a similar problem with power and efficiency readings. Have you tried the mod on the forum about changing the number of turns on the SWR toroid. From memory the ratio stays the same but you increase the number of turns. It fixed my radio.
Thanks Lance! Yes, I did. Actually, in my case the pwr/swr reader was working ok in the beginning and it was with the original 7t T2 :). But when it stopped and I replaced the T2 with 21:3 turns, nothing changed, no work . 73! Linas LY2H
They are 5V relays. Were you by chance hitting them with the 12V power supply? As for the SWR/power/efficiency readings, they all get sent to the microcontroller via 2 wires (plus ground.) Since the circuit was working previously, and then you took out the inter-board connector and had problems with the +12V lead I would guess that you also have problems with the connections to the FWD and RVS pins on the inter-board connector.
With the 2 PCB's connected you can solder small jumper wires from the top to the bottom of those 2 functions on the connectors to see if they are open, or just use your multimeter from the top to the bottom of each connection to ensure that they are all making good connection. I think the weakest part of the rigs design is probably that connector on the edge of the 2 boards.
Thanks John! Well, I can be sure of anything :), but if I would mistaken 12V to the 5V bus... then I had much more problems than relays :) . And it only happened to these 3 bands, while other 2 were functioning just fine.
TNX for the tip on continuity test. I've actually done exactly as you say and found full continuity between the Atmega respective legs and the interpcb connector and then further onto the RF board to the T1/T2 region. Thanks again, 73! Linas LY2H
@@Linas_LY2H, I was afraid of that. From watching your video, you seemed like the very methodical sort, (like me.) So if when you're Xmitting you have a voltage on the FWD line near the microcontroller, then your mocro-controller is damaged.
Well done Linas , thank you for very informative video. I have uSDX+ from China and made a few modifications. I wanted to know,, please, the turn numbers on ferrite toroid cores for each band that you got. Sincerely, Dov 4X1PD 73!
Thanks Dov! I have the Classic version with 80,40,20,15,10m bands . My coils are wound accordingly to schematic diagram which can be found on Manuel’s DL2MAN page. You can go directly to the RF board via this link:
dl2man.de/wp-content/uploads/2022/08/truSDX_RF-Classic_86256.pdf
The number of turns and the toroid’s type is indicated above each drawing of the LPF filter per band. HTH, 73! Linas LY2H
@@Linas_LY2H Thanks Linas ! At the 11th minute you are talking about tweaking filters. By squeeze or spread coils ? 73! Dov 4x1pd
Yes, Dov, I’ve been tweeking filters by squeezing (for increasing the inductance of the coil=getting the resonance dip on the nanoVNA lower in frequency) or spreading (for decresing the inductance of the coil=getting the frequency dip higher) (nanoVNA method for the coils marked LX2, like L32, only. For the coils marked LX1, like L31, the tweeking is also done by spreading/squeezing, just for the max output power with no VNA, with radio connected to the dummy load/pwr meter). Some guys report that squeezing/spreding was not enough for them and they had to remove or add one turn on the toroid (this involves, obviously the removing the coil from the pcb and rewinding.). HTH 73! LInas LY2H
Linas, my friend, your videos never disappoint!
I have had my challenges with my TrSDX. Besides the speaker, it has some ‘birdies’, yet is operable. I have my hopes for the unit, but I don’t have the trouble shooting skills as you.
My preference is to play radio with my QCX Mini(s). I need to improve my CW, and focus on field operations.
I did finish my QDX v3, and hope to go digital in the field. Perhaps you could film a tutorial, kit inventory and field deployment with the QDX?
We are 5,300 miles distant, yet you seem to play radio as I do… I’m adopting you as my Elmer! (HiHi)
de W7UDT Rand
Hello Rand! With your comments, you certainly know how to motivate a youtuber-content creator. Thank you!
The (tr)uSDX surely is an operable little radio, despite all the flaws. It's a perfect example of what can be done with minimalistic digital signal processing.
Congrats on your V3. I have also just finished one and it works ok, especially with the latest firmware 1_07. Today noon, yet another package arrived with the V5 for the High Bands in it! So more happy soldering hours at the workbench!
Thanks for the idea on the outdoorsy video! The key word is "weather" here, as we have lots of wet snow, mixed with rain and wind with temperatures about -5C to +2C. But it will change for good inevitably! CU on the bands! 73! Linas LY2H
I can see the need to add a handheld microphone, and an amplified external speaker.
Yes, it’s possible. The internal mic works surprisingly good though, judging from the reports, but as it comes to the internal speaker - it’s a crap and external speaker is very much welcome. 73! Linas LY2H
at 3:57 I see something I have never seen. but how do you plan to use a similar solution to fix your FETs. can not be done!!!
Hello Luca, thanks for your comment! At 3:57 I show my little mod to the BS170S transistors mounting method on the PCB by using sockets. These sockets are made of the same material as inter-pcb connectors. They grasp the leg of a transistor firmly and provide for sufficient , in my opinion, contact. That’s it. Using sockets I can play with various makes of the BS170 transistor , or replacing them without need to unsolder if they go bust. The sockets do not fix my FETs if they are dead. You can’t fix a dead transistor :), but you can replace it with the new one. Having my sockets in use, I do this easily and quickly. HTH, 73! Linas LY2H
@@Linas_LY2H your solution is only good if you are sure of perfect pin retention. in any case, before starting to transmit, I would always check the position of the three FETs.
@@luca3223 You are right. But the retention is just fine for me, the transistors sit firmly in the sockets , it's like the older microchips- you don't need to check up each time if your chip is still in place :) 73! Linas LY2H
galvoju galvoju, kurgi man girdėtas toks akcentas... but then i look at the callsign! 73s and Slava Ukraine!
Herojam Slava!
@@Linas_LY2H dar klausimas: ar iš UA pavyksta kanors išgirst HF bangose su stacionariom atenom?
Ukrainos radijo mėgėjams negalima daryti QSO dėl karo padėties įstatymo šalyje. Gaila...
@@Linas_LY2H o iš ne-HAM HF dažnių?
Sorry, čia Ham Radio kanalas. General SWL aš nelabai domiuosi, gal reikėtų kreiptis į atitinkamas FB grupes. 73! Linas LY2H