Malahit 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 tuner I'm now more than 8 months out with (tru)SDX, and it has changed my ham life. Thanks, DL2MAN / PE1NNZ ! 73, W-2--- ! ._._.

Remember this is a QRP rig easy 4watts, sensitive receiver, built in keyer, Morse decoder, speaker is small..quality of audio from speaker is poor, earphone much better. Transmitted audio acceptable. CW keyer works well. As with most new computer controlled devices all changes like power, volume , rate of tuning, cw speed, band changing..all require multiple pushes of buttons to arrive at your choice in the Menu. But it is a fun tiny little efficient rig. I love it.

UPDATE: It is now a year and a half later from date of purchase and in addition to a fun little CW rig, it plays well on FT8. I am using the .200i software that comes with it, an easy connection to a PC laptop with WSJT-X and GridTracker on the side makes a nice digital mode rig. A 5 Watt multi-mode, multi-band transceiver for a modest investment. ORIGINAL 4 STAR REVIEW: A nice experiment in cramming a multi band transceiver into a package the size of a pack of cards… It will do SSB but I am a CW guy and this thing is fun to use. Receiver is sensitive enough. Worked a VK from AZ this morning on 20M with a chunk of wire off the balcony. I also have a QCX+ for 20M. Both have strengths and weaknesses but for a palm of hand radio you can stuff in a shirt pocket along with a wire antenna this one is pretty hard to beat…

It is an interesting device; unfortunately, my results have revealed its limitations in important digital modes. In FT8 and especially in WSPR, transmission is unstable or does not work at all on macOS when using an external 12V power source. With USB power, transmission works, but the signal is too weak to be heard. RX in FT8 and WSPR is good. All recommended settings (power, SWR, audio levels, etc.) have been tested without success. Additionally, it appears that the original authors have lost interest in the project, making it difficult to find meaningful support. The (tr)USDX forum is closed.

I take back my earlier review. Today I connected it to a Chameleon Whip antenna and an SWR/Power meter. The meter showed a little over 4 watts and an SWR of 1.0 and I made multiple POTA hunter contacts on 20 meters USB with good signal reports. This little unit works great and is worth the price. Once you figure out the menus it is easy to operate. Works better if you lower the bandwidth as it is wide open unless you change the settings. I use it with a small BlueTooth transmitter and a headset as the audio is not the greatest. Haven't used it on CW yet as i need to improve my skillset.

This is a fantastic little radio. I have made contacts all over the United States, South America, and Europe using this with an end fed half wave (EFHW) 40m antenna hooked to a 49:1 unun from TennTennas and some cheap RG58. I power it with a 3s lipo RC car battery. If you plug in headphones or an external speaker the sound is really good. I've tried using an external mic, but tend to have more positive results with the internal mic. It works great for POTA on 20m and 40m. Of course, most of the time this may be operating at 5 watts or less, so you have to be patient, operate when conditions are good, be strategic when there is a pile up, etc. For the price and size, this thing is sweet.

The one I received didn't work. Trying to adjust frequency step results in the thing switching to CW mode and the enter key not working at all. Combing through the menu items results in the unit randomly switching bands. Try to adjust the volume and the unit switches frequencies. PTT button sometimes functioned. Total junk. If you want something that works, don't buy from this distributor. It's total garbage.

There's not much I can say that that the other positive reviews haven't covered about this unique little radio, but I'll try to add my personal take: 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 regional Reticulum HF links using NVIS on the 6 and 13MHz ISM bands. The radio produces 0.5W from 5V USB power, and field strength tests indicate that the ERP from my very compromised antenna are within legal limits. A zener diode across the RF output will protect the finals from high SWR. This would've been a nice design addition, but it's a low-skill fix. An explanation was posted to the truSDX forums, and a tutorial can be found on YouTube by searching for "Easy SWR Protection for (tr)usdx". I recommend getting some inexpensive USB-C to micro-USB adapters, and keeping a few with the radio. Micro connectors tend to wear out and being able to use standard "C" cables for everything is invaluable. Cons: As stated above, I wish the radio had a USB-C connector. This isn't actually a truSDX design flaw, since the radio simply exposes the USB connector on the MCU it's built on. 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. Overall: This radio isn't for everyone, but it's an awesome, compact piece of tech that'll get you on the air 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 rig.

The tr uSDX 5-Band multimode QRP transceiver assembled by PE1NNZ and DL2MAN is a very well-executed uSDX build. Receiver performance is sensitive and stable across all five bands, with clean audio and effective filtering for a compact SDR. CW operation is smooth, and frequency stability is good once warmed up. Transmit output is consistent across bands, and on-air reports confirm a clean signal with no noticeable key clicks or excessive IMD when properly adjusted. Multimode operation works reliably for SSB, CW, and digital modes. Build quality is excellent, with a neat internal layout, solid case, and low power consumption—making it an ideal QRP and portable rig. Highly recommended.

Fast shipping and great build quality. I recommend!

Une vrai machine! Je pense m’en procurer un deuxième !