18650 Batteries and Charger

[EA2BD]

@2M0OSB

what did you use for a mic on the tr USDX?

Hello,
Sorry, not Fraser, but as a user of truSDX I can tell what I use.

I find that SSB tx audio is poor in this rig, but we all are aware of its minimal design, so it’s good we can still do CW & SSB with this tiny toy!

As I said, the audio quality is not very good, so in order to improve it I did two things:
a) adjust the audio settings via these menus:

• Noise gate = 1
• TX Drive = 2

That reduces the distortion in the digitalisation of the voice.

b) Use an external mic (PC headset) instead of the built in mic.
That also adds clarity in the voice.
To be able to use the mic and add an external PTT switch I added an easy to build adapter.

The RCA connector is for the PTT cable.

The pinout conforms to:

See all details here:

(tr)uSDX - initial thoughts (Part 1)

Hello, I bought one trUSDX in kit form and built it myself (from EA3GCY approved supplier). Soldering process was fun and not that huge, although it’s not a kit for a novice. I had some troubles first and fried the BS-170 transistors due to a bad enammel removal in the SWR measuring circuit toroids. It was good that no alignment was necessary appart from the frequency adjustment easily accomplished by centering the CW carrier on my IC-7300 spectrum monitor. I would support the pros and cons …

Good luck with your truSDX, not a jewel but a fun rig.
73 Ignacio

Ps: I’m using 18650 with it and due to very low current draw it works fine and last very long. Don’t get mad looking for the perfect charger, almost any LiIon charger will do the deal.