SW-3B First Impressions

Thought I would post a quick note showing my new radio for backpacking…the SW-3B

My first impressions are that Rx is much better than the tr(u)sdx, although that’s just a subjective impression, but it is much less fickle when it comes to optimum af gain.

I have been powering via a USB 12V dc dc converter (as in the photo) and have also tried it with a usbc pd to 12v cable ( with a pd chip built into the cable, to negotiate 12V from yhe powerbank)

Both work fine, although the 12V dc dc converter is at the limit of current capability…Of course, you need to select an appropriate powerbank to get 12v with the pd cable.

Output is around 5W using the above (I don’t have a straight key to use for testing the output power, and the radio auto detects I am using paddles)

Have made a few contacts and RBN shows me getting out.

Its a great little setup, especially since I xan use a regular powerbank.

Total cost of the radio came to almost £200 once I had paid VAT on import.


If you hold the Dash contact of the paddles closed while powering up the radio I think you will find that it thinks you have a straight key connected and you can use the dot paddle as a straight key (might be the other way around).


This ham, Adam Filter has also done some extensive testing on power outputs using differing power inputs/outputs on different bands.


Yes this is my method to tune the SW-3B with a manual ATU.

This DC-DC converter manages 3A and I use it to lower DC input of 4s LiPo (14,8V to 16V) to 12V for an output of 5W from my SW-3B. In the picture you see how I’ve inserted the DC-DC converter aside a container for 4x18650 batteries. You can set the output with a screwdriver to any voltage lower than input. Very useful kit and you may have only 4 replacement 18650 for spare (but I think you may complete 3-4 activations before).
73 de Claudio IX1IHR