Saturday, July 12, 2025

(tr)uSDX

 So many things have been written about this little radio. I bought one a while ago. The goal is to bring it with me on vacation. It is not as big and heavy as my FT817 (compared!). It doesn't cover all bands but at the end...what do you need?

I can write a lot of things on how to make a setup. Various firmwares. What you can or cannot do with this radio. But I don't. One thing is for shure: don't have too high expectations. It is a very low priced shortwave transceiver that does what it does. You can certainly make contacts but you need patience.

Advantage is that you can do CW, SSB and digimode. You don't need a external mike, it is already inside. You don't need a digimodem, only a USB cable is enough. 

I don't want to be surprised when on my vacation address so I wanted to be shure everything works as it should be. When you buy this radio it has standard firmware in it. You can upload two types of firmware to the radio. The standard and the beta. Each has it's own features. You need the beta version (2.00x) to work digimodes with a single USB cable.

Actually updating the radio with firmware was a breeze. It was easy. Setting up the radio takes some patience and practice but can be done with some tinkering. Digimode connection takes some tinkering as well. Probably you need to assign another COM port number to the port that connects the radio. And in WSJT-X or JTDX you need to set polling rate at 80 seconds because the CAT connection is interfering with the virtual audio. You can find everything you need on this on DL2MAN's (tr)uSDX homepage. It takes some time but it can be done.

First of all I wanted to know if my signal has been received on CW. At first I transmitted CQ TEST PE4BAS K with my paddle. Nothing seen... even not after a few times. From my own experience I know how bad software CW decoders decode human made CW. So I programmed the same text in the internal auto keyer. After 3 times transmitting the same text I was spotted on RBN.


Next was SSB. You can read everywhere that SSB modulation is a thing with this little radio. Although you see a lot of YT videos from people that actually make SSB contacts. I made a recording with my IC-7300 and discovered that best modulation can be made talking reasonable loud about 10cm in front of the internal mike. 


Now, digital modes with my experimental 3 band halo. I was really surprised how easy it was to make contacts with only 4W from this little radio. It was really a matter of calling a few times and 2 or 3 stations were calling me back at the same time. I'm not shure but I have the impression that JTDX receives a lot more as the WSJT-X software with this rig.











Digimode test with the (tr)uSDX. ODX 15714km. 



You can be heard. But can you make contacts? Luckily the IARU contest is on. So I set a goal to work a SSB and CW station on both 20m and 40m. The antenna is an endfed which is the most used antenna on portable operations. I might bring my magloop on vacation but am not shure about this. With the endfed I can only transmit on 20/40m. I don't know what to expect on vacation so I decided to hang the endfed from gutter to gutter, about 3m above the ground. The worst antenna setup you can image :-). I was operating outside behind the house, my shack is upstairs (the 2 windows). At first I tested SWR. It was reasonable on 20m 1:1,5. On 40m it was reasonable till 7100 KHz. Unfortunately my earbuds fell and one of the earpieces broke. Ah well, this will happen on vacation as well. With this setup I worked RW3DU on 20 SSB, 9A0HQ on 20 CW, OE0HQ on 40 SSB and II4HQ on 40 CW. Yes, it works well.





My test operating position. Need a longer power supply cord because you need to hold the radio near your mouth for SSB. I also ordered a BNC to PL connector. The one I use now is, BNC to N to PL which makes it long and heavy.


This is probably what I bring with me. (tr)uSDX, battery with charger, minipaddle with retractable cord, compass, USB cable microUSB for digimode, USB cable for iphone charging, dummyload optional.

2 comments:

Anonymous said...

Hoi Bas, als je hem in CW gebruikt zet dan de TX delay groter dan nul. Anders is hij heel onrustig.

PE4BAS, Bas said...

Dat ga ik proberen. Misschien lukt het seinen dan wat beter. Bedankt voor de tip. 73, Bas