tr usdx transceiver 5-Band usdx Multimode QRP Assembled with case by PE1NNZ and DL2MAN

This transceiver is designed and built exclusively for Amateur Radio use. In most countries, including the USA, you must have a license to transmit with it, although no license is required for listening (in most countries). If you don't have a license, most people won't talk to you, and they, or government officials, may come looking for you unannounced.If you are a skilled operator with QRP antenna skills, you can make contacts worldwide and beyond with this. (tru)SDX is an amazing SDR design manufactured in China with permission and agreement from the authors. It is amazing how many unauthorized, knock-off, and weird variants there are of this design. One of the common knock-offs based on the (tru)SDX software is called "uSDX".(tru)SDX designed to be multi-band, multi-mode., inexpensive, good, and low power/lightweight. It achieves these objectives.To fully appreciate this rig, you need a full blown commercial multi-band, multi-mode rig to compare it to. (tru)SDX has most or all of the features you'd expect to find on such a rig, although it's much harder to operate due to simple controls and the small size. Instead of traditional dedicated controls, you go menu diving with (tru)SDX.If you try to use (tru)SDX with a compromise antenna, you will be operationally challenged to make contacts. I wouldn't make this my first rig; some experience helps with operation and particularly with the advanced features. It can do many things the big fancy rigs can, but it may be more difficult due to the minimalist aspect of the rig. To truly master the (tru)SDX and learn the user interface will take some time and experience in real use.The rig is made by a CW lover for CW operators, according to DL2MAN's website. Add a key and it's great for CW. In a pinch, use the PTT button can be used as a straight key. I use the built-in Iambic keyer software function with an inexpensive paddle made for QRP use. Receive bandwidths of 200Hz to 4KHz can be selected to dig out signals in pileups. There's RIT. There is a primitive spectrum display! The rig even decodes CW and displays it on the screen, which can be helpful to both newbies and experts if the received signal is clean. I've only used this rig on CW, and it is a ton of fun in the field!To make SSB contacts, you'll want an EXCELLENT antenna, linear amp, or both. The way in which the rig generates SSB is, or should be, award winning. Go ahead, delve into this fascinating topic! However, the signal it produces can be tricky in driving a linear amp. A control line for a linear is provided should you wish to go there. I have not tried the SSB mode yet, I've only studied it. So far.I've made CW contacts on 20M and 40M, and was heard on SSB on 40M within the first week.If you have mental problems like me (!) and a good QRP kit you can use this as a CW walkie talkie! So small, and a minimalist's dream.The point of photo #3 with MFJ-269 antenna analyzer is that an optimal antenna is key. If you use an antenna tuner, you'll be paying an additional penalty of signal loss (>10%) thru the antenna tuner and system. Make your antenna so it's resonant without a tuner (good side of a tuner: this rig has poor output filtering and a tuner will help with that by adding Q, at the price of less power out). Some QRP'ers talk endlessly about end-fed and random length antennas you use with an antenna tuner. My least favorite forms of antennae! My experience tells me you're better off to spend the extra effort to put up a dipole. Even if it's not perfect. Inconvenient, yes, but the results are worth it, and no tuner required. This topic is a black hole.Power - you need to take it with you. This (tru)SDX radio runs off of USB2.0 power! All cellular power gear can be brought to bear. You won't get as much transmit output. But, the whole power thing is simplified and you can share batteries and cables with your smartphone. This has turned out to be a much bigger deal than I ever imagined it would be, and it makes it that much more practical to take tru(SDX) with you everywhere you go! Solar cells are fun and practical to take along. Surprisingly, I did not have electronic noise problems when using cell phone USB battery packs. I used ferrite beads. YMMV.What I wish the rig had:* More bands, especially 10 and 15 meters, but that would make the rig bigger* some sort of built in paddle function for Iambic keying* some sort of primitive and mostly tiny output matching, but not a full blown antenna tunerI'm now more than 8 months out with (tru)SDX, and it has changed my ham life. Thanks, DL2MAN / PE1NNZ !73, W-2--- ! ._._.

This is an excellent radio, especially for the price. It's tiny and light, perfect for SOTA, EDC, EMCOMM. Upgrade to the beta firmware to get the spectrum scope, and adjust your frequency offset for best results. The noise filter works great, but the little speaker does strain and squeal a bit at volume or with a noisy signal. Not even worth demoting a fraction of a star, especially given how every feature of this radio just shines. Super pleased. I might buy another in green. 73 - K7DAB

This is the first HF radio I purchased after getting my general license. This little guy is amazing. I can't believe the contacts I have made on 20m SSB. I use it for POTA, SOTA, with a homebrew EFHW 63' wire antenna. I usually can pull 20 to 30 QSO in 30 min. I have made SSB voice contacts in Argentina, France, Spain, and the Caribbean all on 5w. Don't let anyone tell you this transceiver is a toy. I was able to tune my antenna, cutting the wire to length by using the internal SWR meter while powering the radio using only 5v on the USB port. This lets you tune your antenna without risking damage to the radio finals. Just buy one, you regret it.

Works great. This is an authentic build. DON'T TRANSMIT WITHOUT AN ANTENNA OR GOOD DUMMY LOAD. You will burn out the finals. This is true of just about any HAM radio. This one looks like a toy but it is not a toy. Treat it with respect. I does have a mode for practising CW which turns off the transmitter, but you should connect to an antenna or dummy load anyway, in case you forget and leave practice mode. Watch the various youtube videos by DL2MAN. So much good info.

There's not much I can say that that the other positive reviews haven't covered about this unique little (literally: it is small!) radio, so I'll try to add my personal spin:This is an SDR implemented in an Atmega328 MCU. If you're unfamiliar with the 328, look up up the specs and blow your mind with this marvel of coding prowess.I purchased this radio to experiment with QRPp regional (NVIS) Reticulum HF message relays on the 6 and 13MHz ISM bands. The radio produces 0.5W from 5V USB, and field strength tests indicate that the ERP from a loaded dipole is within legal limits.I also ordered some inexpensive 5V DC/DC buck converters with USB inputs, to give myself the option of running this at higher power from a USB power brick on the amateur bands. I'm aiming for 9-10V, which should be sufficient for JS8 and Winlink, without straining the finals. (The converters can produce up to ~30V out, more than enough to destroy the radio, so take care if you do the same).I recommend getting some inexpensive usb-c to micro usb adapters, and keeping a few in your go kit. If you're anything like me, you have plenty of old A-to-micro cables, but the micro connectors are worn out. Being able to use standard "C" cables for everything is invaluable.Cons:I wish the radio included a usb-c connector, as having to carry multiple cable types (combined with the frequent micro usb connector failure rate) is frustrating. See my comment about adapters above.Turning the volume to "16" causes self-oscillation; don't do it. And don't expect much from the built-in speaker. Use an external speaker or headphones.This radio isn't for everyone, but its well-built marvel of technology at an irresistible price point. If you're an experienced HF operator and/or looking to get into QRP on the cheap, it's a fun little rig.