Wednesday, May 14, 2025

QRP-Labs QMX excellent for portable operations

I've been staying in Tasmania this week, on the north coast, near Devonport and naturally I wanted to bring some sort of radio gear along. The QRP-Labs QMX recently added the ability to transmit sideband. I've had a few contacts with this and reports are good. The QMX (and QDX) are particularly good at FSK modes like WSPR I think due to the direct synthesis rather than audio mixing.

My travel case is quite small and fits everything I need including a pill bottle microphone.


The station was set up overlooking the ocean with a 29' wire pretty much just resting on some bushes.


Operation was on 40m at first but 20m was the standout. I was heard as far away as Europe in the first transmission.


I'm embaressed to admit that the very compact tuner was purchased from China and is clearly a copy of the QRP Guys' Ununtenna Plus. I promise to order the real thing which they say has much better quality toriods in it. The design is good and it's the most compact antenna tuner I can carry with me.

The QMX has a built in tuning mode with SWR display but I find nulling the LED on the tuner is easier.

At first I tried operating inside the house with the wire running out through a metal sliding glass door but I couldn't get it to tune. I think the close coupling to large metal earth threw things off. Operating outside was pleasant and signals were very good.

No comments: