Ham Radio - tr(u)SDX splatter problem, further testing. 

Manual, Ok, Lot's to address, I'll take it a chunk at a time. You say: "The issue could have been resolved immediately if you just had accepted replacement. You insisted, you wanted to fix it yourself, and here we are. I´d have appreciated, if you just had worked with us, trying to resolve the issue, and then make a Video about the solution and the results." At the point in time that replacement of the RF board was offered, I thought it was fixed. The problems I'd had with stability and rebooting were resolved and I saw no need for the replacement board. I was unaware of the modulation problem at that point. However, I would welcome a replacement RF board at this point as I'm somewhat convinced the problem lies in that board. Also, this series is an experiment, sharing each stage of my exploration of the radio. Not just a polished finale, but each phase that leads to the finale. You say: "From a ham perspective, I think you´re mis-representing the whole issue." I'm attempting to be as transparent as possible, sharing exactly what I observe. Nothing is misrepresented or altered. They see what I see. Now to your numbered points. "1. There´s defiantely a different picture remote vs. local. It clearly shows mitigation remote, yet there´s an issue." The entire signal was lower on the remote. Far enough above the noise to be discerned but much weaker than in the local test. The edges of the splatter were not as clear, but still present. It wasn't that it was better, there was just less signal to see. As to Point 2. I have seen a much cleaner signal from another tr(u)SDX with no visible energy in the suppressed sideband. I know the radio can do MUCH better than what I'm seeing. Even at TX drive level 1. And you do concede that my case is abnormal. In line with my repeated statements that the problem is with my radio's build. As to point 3. That is helpful, I'll look at the noise gate setting. I suspected something like that when it was chopping off the audio all together on 80 meters. However, the degree of splatter varies greatly on the different bands, so I doubt a setting that applies to all bands would be the problem. It doesn't chop off the audio on 20 meters and hardly at all on 40 meters. Being frequency dependent like that leads me to think it's something wrong in the RF section Point 4. Bandwidth. The audio is rolling off just under 2 KHz, so there's nothing to modulate above, the filter shouldn't matter. However, I will look into that. As to your last statement, "I find, your videos are not representing the (tr)uSDX Project, and we could have helped you with your issues (as we tried). " As I have stated more than once in the vids, I'm sure the problem is in my unit and not representational of the radio in general. I don't know that I can be any more clear. I didn't feel I was getting help initially. When I emailed pictures of the bad soldering, you initially replied that you didn't see bad soldering. After I detailed it in the video, it was taken seriously and you worked with your builder to get that problem resolved. That was a good result. When I observed the bad splattering, you told me it was artifacts from the digital processing only visible in the near field. That didn't make sense given the magnitude of the observed issue of clipping and splatter, but I gave you the benefit of the doubt and tested it anyway. I will get to the bottom of the issue on my unit and share the solution eventually. I'm sure it will help others who build the kit to avoid whatever the issue turns out to be. This also ties to your final statement: "A guy with your amount of followers should be more interested in "geeting it right" before creating a public false impression, that (tr)uSDX is bad to the bone, which clearly mis-represents the (tr)uSDX Project. I know you don´t mean it that way, but I get mails from people, that are now insecure because of your issues. I´m more worried about the people that did not write me, and just drew the wrong conclusions....." Again, I have stated publicly and in the vids, more than once, that the problem with my unit shouldn't be a reflection on the radio in general. I don't know how I can be more clear. There will be people that jump to conclusions, I can't help that. I'm not hiding anything, I'm not misrepresenting anything. I'll pin your comment and my reply to the top of the comment list so your input can be considered as well. I'm just trying to be fully transparent in my exploration of this radio. Warts and all. I'm sorry you're getting some flack, that is not my intention. When I come back to this project, I'll open the video with a strongly worded statement, again, that my issues are with my one unit and should not be considered a reflection on the radio as a whole. I've said, publicly, in the videos, I've heard from many people that have perfectly fine units without issues. And I've pointed it out yet again here. On the subject of the radio's settings, What should the working defaults be for TX drive, Noise gate, Bias min and bias max? I assumed the out-of-box initial boot up firmware defaults should be close to correct, but that assumption could be wrong. When I come back to the project, I'm planning on going through a complete alignment as one would if building the kit. I still think it's a hardware fault somewhere on the RF board. EDIT: John, AE5X also did a test, looking at the spectrum and using two tone injection to measure IMD. ru-vid.com/video/%D0%B2%D0%B8%D0%B4%D0%B5%D0%BE-iPmv1g9rv7s.html

Luckily DL2MAN found a defective trusdx in his own stack and now recognizes the problem... Sorry that there is so much hate with the haters, ignoring them isolates them...

Love that you and Manuel are able to work together on this.

Manuel you are going to make yourself sick if you keep worrying about every little doubt about your fine work. The value of Kevin's video is showing some troubleshooting techniques, but all you see is "harm" to your project. Stop it (please).

@@KC3DJV they look at odds w/each other to me.....

Limited! Now you are over simplifying things, sir. It's terrible.

It's worth the money for a great little CW rig, for sure. That's primarily what I bought it for and I have no complaints on using it for CW.

T1 and T2, got it. Thanks for the suggestion.

I've used the Web SDR method myself when I've been told my audio is distorted like I have RF on it. Unfortunately in my case my signal came through perfectly on the Web SDR with no distortion so I'm none the wiser!

Engineers! Why? Try fixing it yourself, you'll learn loads!

@@awaismushtaq5719 I learned loads when I began actively seeking anything else other than Chinese crap, which has to be 'fixed' right after it is purchased.

@@lilblackduc7312 LOL 😂😂😆! I love it. Too good! Natural!

@@awaismushtaq5719 I bought a vacuum cleaner years ago and made sure to get an extra drive belt while I was at it. I have parts for my coffee maker & window fan. 😎👍☕I know nothing in the last 20yrs is the quality we used to purchase from Sears. Being an "Electronics Junkie" since after I was born in 1958 just makes my outlook that much worse, Awais. So, there's a "thumbnail sketch" of my 'Model of Reality'...I've become a Daffy, lil' Black duck...🤪😜😁 🤣

@@lilblackduc7312 LOL! You are too good! Yes, and please forget about the quality your and my generation were used to back then, in good old Golden Days of Electronics. I'm pretty much a nerd in electronics, although I work in textiles but because of my undying love for electronics, I have spent last 18 years of my useless life in reading, doing and learning by other means about electronics as much as I could. I own a National two band radio receiver with Cassette Player. It was a masterpiece back in its time yet still serves its master with all its parts in tact although its service life expired about a decade and a half ago.

I mentally filter that. After my vid looking at the audio quality, I heard from several that duplicated the test method. That was the dataset I drew from. Ignoring the purely anecdotal input. My determination was made on the real data.

Conscientious and responsible hams don't knowingly transmit malformed signals that can cause *radio interference* to other stations or services, that's why not.

Kevin's just checking to see if that (tr)uSDX is throwing out Gamma rays...

Yep! I left it in to see how long it would take for someone to guess. :-)

Yep. Way to think it through. That's what ya gotta do. Maybe that would be a good T-shirt. :-) It's also putting the kabash on my shield idea. Back to electronic flaw hypothesis.

FECES!

A couple of vids back I looked at the audio and signal in AM and FM. There was no distortion, just low modulation. I got right down on the mic and spoke loudly and the audio was still clear, no clipping. So it's not a problem with the mic or any analog circuitry behind it.

@@loughkb I'm referring to frequency roll-off both above and below audio spectrum limits. Not audio modulation amplitude (including high clipping). I need to eyeball a schematic, I may be talking out my butt (pun intended). Great videos by the way !! Been meaning to write for some time now.

I just sent you a FB MSG.. Hope I got the right guy... Or someone is going to think I'm as weird as I really am. ... Let me know what you think as I may be looking in the wrong place, it's getting late, I'm half blind and my brain don't work this side of darkness outside...

The audio in am and fm was rolling off below 2KHz. Nothing high to modulate. No, I'm pretty sure it's something in the RF section.

Hello Bill, this is NOT a 'Class-A' or '-AB', nor a '-B' -radio! Please RTFM before telling something like that, ... ! It's not a 'linear-amplifier' in this "PA" ! Only 3 small BS170-FET's, generating close to 5W, with an 'eta' of 0,8 and better, ... ! (Eta> 80%) It is a little bit 'more complicated', not as 'rocket since', but nearly on, ... ! Modulation of phase and amplitude inside the frequency domain! Not a 'simple ring-' or 'diode-mixer', or something similar simple device. It's all a kind of DSP-formula inside the 'Arduino-IC' that generates the SSB-Signal. And, ... don't forget, it's a simple experimental SDR-TRX, for less then 100€ . No one is advertising a 'Yae-Com-Wood' for +10k$ with 'absolute' preformance, ... ! Please hold this in mind ! 73 de Markus ; db9pz [ Owner and 'proud' user, of a 'homebrew' (TR)_U_SDX ]

Two or three videos back in the series.

@@loughkb Have you tried using an audio signal generator with adjustable attenuation ? I don't suppose another microphone. Maybe putting some ferrites on the mic lead? just a thought. I suspect a problem solder joint might be acting as diode and creating some weird mixing effect. G7VFY

This is a parade example of what I mean in my comment: Kevin just "pushes" and you immediately assume, it´s the designers fault. There´s a lot of inconsistencies in his testings and conclusions. That is denial.... I am DL2MAN, so I can tell you what I think, he should do: Accept he has a bad device, accept the replacement, that was offered by sunny right away, and be happy. If he wants to tinker: Good: But don´t misuse your high subscriber count to make it look, like what he´s showing is normal, and Kevin needs to save the world from us. Shame ! 73 Manuel; DL2MAN

No need to attack me Manuel. I think your anger at the comment by Louis above was misdirected my way there. I have stated several times in the videos that the issues are with my radio and not representational of the project in general. And, the replacement was offered and declined *before* the issue with modulation was discovered. At this point, with the continuing issues I would welcome a replacement RF board.

@@dl2man You yourself are creating bad publicity for your product, VK3HJW

Earlier in the series, I tested audio on AM and FM and the audio was clear and under modulated, even with me speaking much louder and closer to the mic. So the mic and any analog circuitry between it and the digital side is fine. studio.ru-vid.com8PDcy7vYduY/edit?o=U

That's done in software on this radio, there is no physical balanced mixer.

@@loughkb IMHO, That would make me suspect it even more, since CW is fine. Balance in the mixing stage is extremely critical for carrier suppression and would affect bandwidth directly.

@@paulblock1367 You can't really apply classic analog theory here. They are creating SSB through software in an entirely different way. Nothing at all like a balanced mixer.

Thanks for bringing that to my attention Louis. For others reading the comments. This vid is John, AE5X, looking at the IMD of the output with two tone injection. Go watch, it's informative.

Nah, as I said in the vid, it's a great little CW radio.

The designers don't sell these radios directly. They authorize, endorse and promote specific overseas Chinese sellers to fabricate the PCBs, source the components, then assemble, QC and sell the units to the consumer. If the assemblers in China are free to specify components manufactured for the domestic Chinese market, they may be of widely varying quality. It's my suspicion this may be the problem. If there is a kickback to the designers based on the quantity of radios sold is not clear, at least not to me. Kind of an odd arrangement they have. Puts them out of direct control of the manufacturing, but also shields them from direct responsibility for product defects, returns, and refunds. Whatever the business arrangement, the designers contend that the signal spattering and intelligibility issue is a rare occurrence. And that most reports of it are either due to user error or improper test methods to observe the signal quality.

@@R50_J0 Yes I know a lot of the history, but surely they must have retained some sort of control over the licencing of their intellectual property? If not why are they now just giving money to Chinese manufacturers? Unless of course they simply sold the whole IP to a Chinese middleman "franchising company" for cash and washed their hands of all further involvement? As you say an odd arrangement, if you value your reputation.

Go back and watch the earlier vids in the series. Info from my first vid about the poor quality soldering is now being used to train the builders. After my experience, Manuel requested samples from stock to further inspect their quality. We put things in motion. I'm sure they're doing a better job now.

@@hectorpascal You're thinking along the lines of a traditional businessman. I suspect the designers don't have a strong profit motive, if any, nor are they trying to start a full time business with the radios. They have come up with this oddball manufacturing and sales plan leveraging the cheap costs in China. Probably to avoid the time, effort, and responsibility involved running a business. The Chinese companies probably finance the materials and labor and are rewarded by sales driven by the designers marketing to a niche crowd here in the West. It's a win-win for everybody as long as there aren't quality problems. Basically they seem like inexperienced, naive hobbyists trying to make a ham toy available to us at a cheap price without actually starting a business and all the hassle associated with one. The down side is a lack of direct control over the manufacturing and an unclear responsibility when there are product defects or complaints.

I'm going to have to start copy pasting this reply. As seen earlier in the series, when we tested AM and FM, the audio was clean and free of distortion. Even when I got close to the mic and spoke loudly. So the mic and any analog circuitry behind it is not the problem.