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May 17, 2024. Caveat Emptor

Any blog readers own one of these jewels? It is the uSDX, an Arduino + Si5351 driven SDR transceiver. 




This particular unit was hand built by me about 3 years ago. At that time, buying a bare PC Board and hand stuffing it was the only option. Now kits and finished units abound. Much like the Nano VNA prices are all over the place and many clones are evident. Another critical Nano VNA connection many of the variants simply don't work.

Amazon sells various units at varying prices. The original SDX work was done by Hans Summers and piggy backing off of that effort DL2MAN (Manuel) and PE1NNZ (Guido) did a lot of work to provide many features and of course SSB and CW capabilities resulting in the (tr) uSDX. Their offering is about $140 at Amazon who is one of the official sellers of the (tr) uSDX. 




These two hams now offer a unit which is a 5-band unit. Many of the clone units being sold are 8 Band units. Missing is 15 -- 10M on the (tr) uSDX

There are some amazing innovations in the design and the Arduino is packed to the gills with code. New firmware from Manuel and Guido yields a limited window spectrum display. The (tr) uSDX fits in the palm of your hand! It can run off of 5 Volts via the USB port and put out 0.5 watts. At 12VDC you get 5 watts.

I was disappointed with my final result with the version I built. (3 years ago) It worked OK on receive but sounded awful (like crap) on SSB. The Opposite Sideband Suppression on the (tr) uSDX is only 30dB down so not near what is possible even using a homebrew 4 pole crystal filter.

So, if anyone has a later version that actually works on SSB, please drop me a line at my QRZ.com email address or if that is too hard then use this email.



The (tr) uSDX is a really small unit and assuming it works OK on SSB would be ideal for the usual SOTA POTA adventures. 

73's
Pete N6QW

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