The (tr)uSDX has been a much-anticipated QRP transceiver for those of us who love playing radio in the field.
What’s not to love? It sports:
Up to 5 watts output power
CW, SSB, FM, and AM modes
A built-in microphone
Five bands: 80, 60, 40, 30, and 20 meters
A super compact and lightweight form factor
An open-source hardware and software design
Super low current consumption in receive
A super low price of roughly $89 US in kit form and $143 US factory assembled (via AliExpress, but there are numerous other group buys and retailers)
Frankly speaking, this sort of feature set in such an affordable package is truly a game-changer. Back when I was first licensed in 1997, I could have never imagined a day when a general coverage QRP transceiver could be purchased for under $150 US. The price is almost unbelievable.
My initial impressions
On Wednesday, March 30, 2022, I took the (tr)uSDX to the field to attempt a Parks On The Air (POTA) activation. I had only taken delivery of the (tr)uSDX about 15 hours beforehand and had only had it powered up for a total of 30 minutes the previous day. Most of that time, in fact, was checking the power output at various voltage settings into a dummy load. I did make one totally random SSB POTA contact shortly after hooking the radio up to my QTH antenna.
Leo shared some photos of a complete radio kit he built around the QCX-mini along with a ZM-4 ATU kit he also recently built. Leo has kindly agreed to share these on QRPer.com.
Attached is a photo of my ultra light kit.
It consists of a QCX-Mini 20m version (self-built), K6ARK EFHW, Palm Radio Pico Paddle, Eremit 2Ah LiFePo battery, headphones and a few cables.
I usually also carry a small arborist kit and if there is still room also the 6m mast from Sotabeams, depending on what I think will work best.
I chose a hard case and went for the Peli 1060 Micro. It has room for everything I need and it could easily hold a bit of RG316 coax in addition (even more if I chose to shorten the 30m arborist line).
John reviews both the build and performance. He even put the TR-35 on his workbench and measured a number of parameters.
In short, the little TR-35 does exactly what it sets out to do and packs a surprising amount of performance.
John and I actually had a TR-35 to TR-35 exchange a few days ago (if not mistaken, the photo above was taken after that exchange). I was lucky enough to catch him as he activated a POTA site in Texas. From this end, his TR-35 sounded fantastic.
I’m putting together a review of the TR-35 which will likely appear in the May or June issue of The Spectrum Monitor magazine. I’ll eventually send this little TR-35 back to WA3RNC (it was very kindly sent to me on loan) but I do plan to purchase his TR-45 Lite kit when it hits the market later this year. Why? Because I don’t have enough QRP radios, that’s why.
Good morning Thomas, from wintry southwestern Ontario.
I thought I would send you a quick message to share my experiences, so far, with the little TR-35.
Yesterday, around 3pm, I took the above unassembled kit off the shelf and began to melt solder. The smoke test was successfully performed the next morning at 1:30am, after non-stop building (with the exception of a few hours for eating and catching up on a little tv). I measure twice and solder once hihi.
I had my calendar marked for February 15 to check the site again for the 3rd batch as I thought that was the day they planned to issue another pre-order.
My buddy Eric (WD8RIF), who is the President of the Athens County Amateur Radio Club (ACARA), contacted me yesterday asking if I knew of any QRP kits designed with phone/SSB operation in mind. One of ACARA’s members was searching for one.
The only other kit I could think of was the new (tr)uSDX. When Eric asked for a link to the product, I went to the Rowaves site and discovered that they were taking pre-orders for the third wave of kits. Like, right then and there!
Without hesitation, I added one to my shopping cart and checked out.
I thought perhaps Rowaves caught up and no longer had a waiting list. This morning, when I checked the site again however, it appears they’ve sold out of the third batch.
Without Eric’s prompting, I would have never thought to check the Rowaves site yesterday.
Side note:There are various (tr)uSDX group buys out there. I don’t completely understand how they work, but perhaps someone with more experience can comment. DL2MAN has information and links on his webpage.
If I’m being brutally honest, the (tr)uSDX kit is a bit intimidating for me. I recently referred to myself as a “gross motor skills” kit builder. I think that’s a pretty accurate description. I’m fine with through holes, simple toroids, and very clear, illustrated instructions. Truth is, I absolutely love building kits. But I’m not an electronics engineer, so when instructions are vague, I can get lost quite easily.
The (tr)uSDX toroids don’t look terribly complicated and all of the surface mount components are pre-installed. Still: it’s a wee kit and I’ve yet to check out the build instructions.
Many thanks to Bill (W4FSV) of Breadboard Radio who shares the following announcement:
40 METER “Woodpecker” QRPp Transceiver Kit From Breadboard Radio
Breadboard Radio has just released the 40 Woodpecker, a 40 meter low power CW transceiver for the 40 meter band. The Woodpecker features a crystal controlled transmitter with a 500 milliwatt output. The transmitter provides sidetone, receiver muting and QSK with delay. The Woodpecker’s direct conversion receiver has an adjustable bandpass filter, attenuator and an audio amplifier suitable for headphone level output plus a selectable low / high filter which helps with band noise and static crashes. The kit is supplied with crystals for 7030 and 7056 kilohertz. Other frequency crystals may be user supplied.
The designer, W4FSV has made multiple contacts using a 40 meter dipole antenna including many from 500 to 1000 miles. The kit is complete with all parts including a cabinet and attractive front panel plastic decal. A two channel 30 meter version may be available soon. A 60 meter version is also available.
Several subscribers asked if I tried using the attenuator and RF gain to mitigate the level of overloading. Attenuators and RF gain can be an effective means of mitigating noise levels, but they essentially affect everything on the band–all signals somewhat equally.
A better approach is to use a BCI Filter.
BCI filters reduce or notch out AM broadcast band signals so that they don’t overload your receiver.
BCI Filters are placed between the radio and the antenna. They can have a dramatically positive effect if you live near a broadcast station and/or if you have a radio that’s prone to overloading.
I see them as a more “surgical” approach to solving broadcast band interference.
I recently finished my Phaser digital mode QRP transceiver kit and have had a hankerin’ to take it portable, and today was the day.
Temps were in the upper 60s with clear blue sky. About fifteen minutes from home is the Watauga Point Recreation Area on Watauga Lake in Carter County, Tennessee. It’s a day use area and is not an official POTA site, though it is in the Cherokee National Forest, which is. I opted to not make this a POTA activation as it was more of a first time “proof of concept” trip.
The Phaser is a small digital mode transceiver designed by Dave Benson, K1SWL with the enclosure the design of AA0ZZ, Craig Johnson. Phasers were available for most all of the HF bands, put out between 3 to 5 watts, and in addition to FT8, have the ability to program a second frequency to operation other digital modes such as PSK-31. They were sold and supported through Midnight Design Solutions, but unfortunately are no longer being offered. Occasionally I see them coming up for sale on the QRZ.com swapmeet forum.
In addition to the Phaser, I brought an FT-891, an LDG Z-11Pro 2 tuner, a netbook computer, and two batteries; a small AGM for the Phaser and a deep cycle lead acid power pack for the FT-891. I brought my W2LI magnetic loop antenna and a homebrew “NorCal Doublet” that sets up as an inverted V on a 20 ft kite pole as a backup antenna. The whole kit (excluding the batteries) fits in two wooden ammunition crates which make it really easy to drive, set up, and operate.
One note on using the W2LI mag loop. You need to first tune the antenna using the radio and listen for an increase in the background noise level. Using the Phaser while connected to my computer made that not possible. If I had brought a small set of earphones I could have plugged them into the audio out jack on the Phaser and tuned for max background noise. So, instead I connected FT-891 to the loop and used it to tune the antenna to 30 meters. Next time bring earphones.
After about fifteen minutes I had the station set up. The waterfall on WJST-X showed that the Phaser was receiving transmissions but no displayed text. Unfortunately I had neglected to synchronize the computer clock before I left the house. The netbook is pretty old and the internal battery needs to be replaced. What to do? First I tried to manually sync the clock to WWV but Windows 10 won’t let you set the seconds in the clock to 00. As I had cell service I figured I could use my cell phone as a hotspot. Never having set it up before I have to say that it was pretty easy. Thank you 21st century tech! This allowed me to sync the internal netbook clock, but it also let me log contacts on QRZ.com, and check my propagation on PSK Reporter.
The Phaser puts out around 3.5 watts, so I didn’t respond to a CQ that was less than -5 dB. While PSK Reporter showed reception of my signal up and down the East coast, contacts were scarce. I seemed to have a window open up into New England as I worked PA, MA, and CT. I was right in the middle of my fifth contact when the computer battery died so that was it. WSJT-X reported these stations on the +dB side for reception but my signal strength was always reported at < -10 dB.
The 30 Meter band was up and down with band conditions being reported as only Fair on the Solar-Terrestrial Data report on QRZ, and at one point for about a half hour there were no signals displayed on the waterfall.
With a loop antenna on a tripod and 3.5 watts I can’t complain. I’m thinking of building an RF amplifier to boost the output up to 10 watts which should help. My next step is to load WSJT-X on my tablet and see how portable of a kit I can assemble. As FT8 was designed as a weak signal mode, it’s perfect for QRP portable operating.