Exploring the QRP Labs QMX - Review and Walkthrough

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Күн бұрын

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@nohill4climber Ай бұрын

Great review Joe. I am a QRP-Labs junkie and qrp rig junkie in general. I've built all of the QMX rigs so far. I've never understood why so many people get hung up on the 12 volt limit. I operate all of mine from battery only using either Lipo, 18650s or even lead acid on the bench. 3 cell Lipo or 18650s full charge is approximately 12.3 to 12.6 volts. Those few tenths over 12 fall off very quickly, and on a reasonably resonant antenna do no harm anyway. Also, stopping the charge at 12 volts will not harm those batteries. I don't own a buck/boost converter. Being a SOTA activator I don't want to carry any more gear than necessary. If a person only operates from a 13.8 bench supply I can see the reasoning for conversion, but I simply use my batteries even at home. I hope that helps someone decide on voltage. I also own an MTR 3B, and the older 4B (gray case). They mostly stay on the shelf since I started building QRP Labs stuff. I do take the 3B on a couple of summits a year. They are great radios, but with limited bands and features for the price. Again, very nice review! Ken, w4kac

@JoeN2DI Ай бұрын

Thank you Ken! I hope it didn’t come off as discouraging to perspective QMX owners. It’s kind of a trivial thing. I just wanted to point it out because I’ve seen a few folks think that there was something wrong with their rigs. 73.

@nohill4climber Ай бұрын

Not discouraging at all Joe. I guess I read the QRP Labs group too religiously. Just seems a lot of folks have trouble dealing with the 12 volt thing when there are a number of ways to do it. I’d have more trouble with 9 volts myself! Thanks for your content. I’m a subscriber as of this morning. Ken

@votisb 27 күн бұрын

Great video. I love the QMX and the QMX+. I've built 2 QMX and a QMX+ and am just in the process of building a QMX mid band. A quick note on the power protection. You can turn this off completely or adjust the over-voltage at which it kicks in. You can also turn off SWR protection or again, set the SWR at which it kicks in. Personally, whilst I'm very happy running it off a 3s lipo which is 12.6v fully charged I'm a little more cautious with a 12v lifepo4 or lead acid battery as these are 13.6v + which is right on the edge of what the rig will take. I have run them at these kind of voltages but only with a resonant antenna and using CW. I'd not risk FT8 or a poorly tuned antenna.

@JoeN2DI 27 күн бұрын

Thank you! I normally run mine with a 3s lipo pack that I home brewed for my KX2 but I just started using a power delivery power bank that I found on amazon for $20. That's actaully what I have the QMX propped up on in my latest video.

@DaDitDa Ай бұрын

According to QRPlab specs, a QMX built for 12 volt operation will function from 6 to 12 volts -- with reduced output power at lower voltages.

@JoeN2DI Ай бұрын

Ahh yeah, you're absolutely right. I said + or - 1 volt when I meant +1 volt. Thank you for pointing that out.

@janiceemery2008 Ай бұрын

Excellent break down Joe of the QMX and the comparison. Now, I have to consider both but, I think you are right the QMX is probably the winner. Thank you again Joe for the review.

@JoeN2DI Ай бұрын

My pleasure.

@N4AAJ Ай бұрын

Gear acquisition syndrome, LOL! I suffer from it as well, Joe :) Great walk through and review. Thanks for sharing, and thanks for the POTA QSOs. 73 es cu on the air!

@ai5dd Ай бұрын

I own a MTR4B (Mountain Topper), I have built two QCX-Minis, I have a pre-built QMX High Band and I am currently building a QMX mid-band ( main board complete, just the LCD control board left to build) I highly recommend the QRP-Labs QMX. I activated POTA mostly with this rig and a Chameleon MPAS Lite or Tactical Delta Loop and I get very good results. This rig is outstanding. 72 de AI5DD. Subscribed. In my most recent video I'm using this rig in my Jeep in the rain. P.S. I don't use the CW decoders. :)

@JoeN2DI Ай бұрын

The Salty Ham! I love your channel! Yeah the QMX is my favorite now. BTW - I can't use decoders. My brain turns off when the decoder turns on.

@msgaltman3075 Ай бұрын

Thank Joe. I had no idea you could view the actual SWR in the Harware Test menu! Does the SWR test trigger the protection if you tune wrong? If you understand the rather complex instruction on using the filter functions, I for one would like to see a video on that. I just don't get it. Aside from the various filter parameters in the setup, is there a quick way to vary the filter with while operating without diving into the menu?

@JoeN2DI Ай бұрын

Yes, the protection will kick in if you go too far out of whack with the tuning but if you set the output power to 50% or 60% it is usually low enough to not trigger the protection. I’ve figured out the filter stuff after a bit of head scratching and it comes down to what CW pitch you use. You need to enable and select filters that center on whatever CW pitch you selected. I’ll try to crank out a video for you because sometimes seeing it makes it easier to understand. As far as selecting the filter, it seems the only way to select it is to go into the menu. Hope that helps.

@msgaltman3075 Ай бұрын

Thanks for super-fast reply and good info. Looking forward to the filter video

@JoeN2DI 28 күн бұрын

Ok you are all set. I just published a video on seting up the CW filters for the QRP Labs QMX. Enjoy!

@rclewen Ай бұрын

Nice overview Joe! I am on the list for a prebuilt mid band QMX and hope to get it before the end of the year 😀 I currently have a 20M QCX Mini and love it! N7BBQ

@JoeN2DI Ай бұрын

Thank you! The mid band one is the way to go. I wish it was available when I ordered mine.

@JohnTrefethen Ай бұрын

Thanks for another concise video, Joe. My kit is en route this week. I am looking forward to building my first radio. Before I do, I was planning to go the 9v route. Can you explain the benefits of the 9 vs. 12v configuration? Can one still achieve 5w output with 9v input? Thanks in advance, N7JTT

@JoeN2DI Ай бұрын

Hi John, you can get 5 watts of output from either 9v or 12v of input. The only difference is that the radio will be drawing more current at 9v. I guess it comes down to what batteries you have available. Most of my power sources are closer to 12v than 9v so I opted for 12v. I just use a buck/boost converter. I’ve linked it in the description. I attached some short wires to it with powerpole connectors and just put it between the battery and the rig.