Its ganing respect with me for what it is. 59 SSB into Croatia last night on 20m with the main station antenna but only 5/6 watts and an external hand mike.
I will be in Mallorca in August and plan to do a few SOTA sites from there and this will be coming along.
oui j’ en ai eu un mais quand on est en émission il faut baisser le volume car on en prend plein les oreilles : je l’ ai eu et vite revendu;
un USDX+ ne fait pas cela et en plus il est CW/SSB et très léger et a une batterie interne.
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Sorry to rekindle an old topic but here’s another vote for (tr)uSDx on SSB.
I was out on GW/NW-049 Gyrn Moelfre today and only used the (tr)uSDx into a 40m EFHW, but managed 40 SSB contacts, 27 on 40m and another 13 on 20m in 45 minutes.
I was expecting to have to get the IC7000 out after a bit of a play with the (tr)uSDx, but no need 
I was using headphones and a Boefeng fist Mike with the Jack replaced.
The (tr)uSDx clearly has some limitations. At times I was really struggling with close by stations, but only realised on the way back to the car when my brain had thawed a bit, that I could have narrowed the receive filter a bit more which may have helped. The noise reduction seemed to work well set at 2 or 3.
Have to say the audio from the built in speaker is awful but not bad with headphones.
Paul
MW0PDV
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Thanks Paul,
I’m mostly a chaser and I use my (tr)uSDX built from a kit in the bush where the noise is zero. I have had excellent results with both CW and SSB and lately FT8.
My Australian put together kit was about $70, so I wasn’t expecting FTDX101D performance. I use a very small powered external speaker or headphones.
Have managed contacts with Europe, UK and USA on phone and cw.
Nifty and fun. Give one a try if you are inclined…
Happy SOTAing everyone
Ian
VK5IS
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I have the “red corner” clone uSDX, and use it with great success, but only on CW. It covers all bands 80-10, with output varying from 4 to 11 watts. It’s not tiny and not super-light and certainly has its deficiencies, but an external speaker eliminates the nasty feedback and the long internal battery life, good sensitivity and selectivity (I never change from 500-kHz filter), and built-in power and SWR meters make it quite nice to use. JS6TMW
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Owen Duffy has posted some additional comments on the poor performance of the (tr)uSDX. His comments don’t surprise me at all. (tr)uSDX IMD performance – owenduffy.net
The worrying aspect to me is that people are using these radios with amplifiers.
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One of the difficulties with the USDX series of radio is that they do not all behave the same way. I’ve heard a wide variety of voice quality from them and equally have heard a wide variety of reports on the same signal. Including one that sounded like it had 20% distortion on frequency, looked wide on the spectrum of my home station, yet another operator said he disagreed and the signal sounded good to him. Allowing for variations in ears and perceptions, I think a marginal signal quality can be mistaken for an acceptable one, but when the distortion is making the signal almost unreadable on frequency (at a signal strength of around s5, so no chance of any receiver problem) and is shown in wide sidebands spreading out +/- 5khz, I think I’m justified in reporting that the signal is substandard. Indeed it would be an obligation to report what I observe.
By way of comparison, one of my occasional contacts on 40m is is a vk3 running a high end Flex SDR, and on my IC7610 spectrum display his signal shows as a rectangle of power with nothing in the adjacent channels. Switching to the USB on his LSB signal, there is no signal apparent, but his signal was s9+ on LSB. I asked him to look at my signal from the 7610 and he reported a similarly good quality signal. From that I take it that the receiver is quite capable of assessing the bandwidth of incoming signals at least up to s9. So when I hear and report a signal as distorted, that report is a credible one.
Owen’s article is worth reading and digesting.
73 Andrew VK1DA/VK2DA
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What I like about Owen Duffy is that he applies sound, state-of-the art methods for answering amateur radio issues. After all, science is the foundation of our hobby, and counting QSOs and anecdotal impressions are much less informative than measurements and reasoning.
73 de Martin, DK3IT
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This is true, but we also go off the deep end at times focusing more on the measuring than the using. I see the same thing in photography, where photographers agonize over ever-increasing deep dives into the ultimate resolution of the lens or camera and in the shooting sports where people agonize over mechanical precision differences that would never matter in field use. It’s called measurebating.
Chris
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Just saw this thread. Mine goes dead intermittently then maybe comes back on in a few seconds, or maybe not. No fun in the middle of a pile up. I have corresponded with the developer and I have had it looked at by ham friend who is an electrical engineer (he replaced some parts) but it still does it. I had great hopes. I can’t imagine risking it’s use again. Scott NZ4R
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I had (and partially still have) troubles with mine. It locked up when turning the VFO knob quickly. Not that this is very relevant for SOTA but it destroyed my trust in the unit.
It got a lot better after I reflowed every component (yes every component) with leaded solder. I noticed that for example under one capacitor a via was placed that took away all the solder and the capacitor had no or bad contact.
I suspect there still one part not properly connected causing issues. Maybe I will reflow with hot-air.
And looking at the forum of the developer it got very quiet. People are selling their units. No firmware development (published) happend since a year. So I think the project has grown to fast and people were expecting too much. That caused a lot of frustration for Manuel and Guido.
That are my personal observations and might not reflect reality 
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No firmware development (published) happend since a year.
They just released a new beta version two days ago, featuring a spectrum display:
https://forum.dl2man.de/viewtopic.php?t=863
Also, there’s still quite some activity in the forum.
vy73, Peter HB9TVK
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Thanks for the hint.
I think I checked a week ago in the changelog and did not spot any news.
Will give it a try. Maybe it will improve stability and reduce the audio chirping too.
Edit: Yes 2.0t firmware does reduce the audio chirps. Still not 100% stable but as stated that is a hardware issue on my device.
73 Joe
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I accidentally mismanaged my Wordpress, that creates an empty link to my previous post, apologies to SOTA readers.
Here is my personal impression about the uSDX and truSDX as a home brewer:
Home brew uSDX and truSDX
3 Likes
Thank you very much.
Can say that there are a lot of good words about (tr)uSDX) or uSDX, etc rigs.
But IMHO, your tests showed what we got during real communication.
E.g. two strong stations with levels e.g. S7 and S9 produce inter-modulation harmonics with levels like S5-S7. In some cases you might start responding to non-existing CQ or you can hear number of birdies.
Friend of mine sold this RIG (tr)uSDX due to reason above - cannot use this rig in CW.
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Your friend had not sold his rig if Guido would have had the original NorCal 2030 front end implemented with bandpass filtering (QCX-CW followed that path, has a solid -129dBm, reviewed by ARRL).
Lot of interesting improvements for uSDX and truSDX
uSDX drain modulation
http://samy9900.livedoor.blog/archives/11432350.html
uSDX88+, empty oscillator can for shielding.
http://www.cqham.ru/forum/attachment.php?attachmentid=385936&d=1678234897
truSDX, improved 5V supply by 4th order LP filtering
https://forum.dl2man.de/viewtopic.php?p=5926#p5926
etc…
Cheers
Pascal
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I really fancy one of these little units, could be just what im looking for! who sells them built and complete in the UK? or if anyone has one they no longer wish to play with, I could be interested!
I do most of activating VHF, but this little unit could be the difference between a wasted trip, or a successful trip when activating the more remote spots!
Cheers - Alan
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Well, considering that you get 4 bands on the MTR and that would require 4 QCX mini units… 
This topic was automatically closed after reaching the maximum limit of 100 replies. Continue discussion at (tr)uSDX - initial thoughts (Part 2).