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Re: Antenna Tuners for QMX and QMX+?


 

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My not so humble opinion (because of 65 years of experience and many mistakes) is this:

Forget an automatic tuner with a QMX or QMX+ or any QRP Labs radio. With an antenna that is not matched correctly (see my rant about using an antenna analyzer elsewhere¡­. If you don¡¯t know where you are how do you plot a course to get where you want to be?)

Any of the recommended manual tuners will work well. I have many and they all work. My old and venerable Emtech ZM2 ?still works well after 20 years of use.
And my more recent 4SQRP Club tuner (I had one, sold it, regretted it, and built another one) works well.

They both work well. ?And I have heard many good reports about the one from eBay listed in this email series. ?Make sure you have the correct build instructions because there have been some errors. ?If I remember correctly the two listed above have a ¡°tune¡± position that protects the finals.

The only automatic antenna matching devices I trust are the ones in my Elecraft radios. ?They will tune a wet noodle but the finals are better protected in those radios. And my LDG auto tuner that I still use with my venerable Ft-817 when I feel nostalgic. ?But the Ft-817 finals can stand the small elevated SWR in the tuning process. ?But that will kill the QMX+ finals with an unknown antenna. ?

One of the reasons I like manual tuners is that I can see the position of the adjustment knobs and with my home QTH antennas if the SWR is off with the latest settings I know something is not right with my antenna. ?In portable use that idea doesn¡¯t ?work. Every set up will need some adjustment. With an automatic matcher one can even leave the antenna matcher in the dummy load position (or wrong antenna) and think your antenna is just fine. ?Some make contacts in error in that position and prove what QRP can do.?

Summary: Use a manual tuner with the beautiful and wonderful QRP Labs radios and play radio. ?Learn to use even a cheap nanoVNA for the simple SWR evaluation. ?They are low cost and tell you so much, especially when cutting the wire for a new antenna. ?It¡¯s use should be part of the Extra Class license exam. So many Extras are intimidated by that simple device. Once a new ham learns that his eyes light up and he knows he has learned something important.?

Dave K8WPE

PS ?Now I understand¡­¡­ He who dies with the most toys has probably forgotten much what he has and why¡­¡­. So true!





On Feb 17, 2025, at 3:32?PM, Tarmo K via groups.io <lennuki@...> wrote:

?QMX+ does not work with ATU-100. QMX+ goes into alarm during automatic setup. ATU-100 with reduced transmission power will not tune automatically.

QDX and ATU-100 work together.





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