Building The QRP Labs QCX Mini CW Morse Code Radio. 

Much welcome George :-)

Right! I've been wanting to get one of those.. No idea why I've delayed..

Ok thanks. My hearing isn't that great anymore I fear..

Thanks!

Also yes! I built two K1s and one K2 :-)

Wow, good lesson about early adoption here..

All right thanks, I will be reposting soon :-)

Thanks. Portable, antenna size is usually not a problem..

I have a video on it ;-)

Yep I know.. It only changed three bars on the same number.

@@RadioPrepper Ok, only changing three bars on the same number is not right. the original batch had some bad op amps, that variety of op amp had all different manufacture dates stamped on them making me think the board house got a good deal on a bag of seconds that mostly worked ok but had several duds in the bag. My recollection is that it produced similar symptoms at least some of the time. I think Hans switched board houses and now he tests every board before he ships it. So if it’s from the first batch that could be the problem. Replacing the bad op amp fixed it but you had to diagnose which one was bad or replace all the op amps of that variety. Rarely you get a surface mount part where the solder joint is marginal and might fail. So it might have gotten through hans’ test, failed later and probably still looks ok. Not it might not look ok, so microscopic like inspection of all the op amp pins might produce a suspect. That would be a long shot but might be cured by reheating the joint if you could figure out where the problem is. If you ask on the list, someone who had this problem will probably remember the details and be able to help you, if that’s what is going on. The op amp variety in question is a low power consumption one with very good performance but that performance is really critical only in one location and the rest can be replaced with a cheaper variety with little change in overall performance. From around January of 2021: “I'm happy to say that my 20m QCX-mini now has a receiver with balanced/ quadrature I&Q! It turned out to be IC7 and once I managed to replace it all was well. FWIW it turned out all I needed to do really was use my finger to fault find. Holding a small metal probe to the inputs of each op amp in the audio chain in turn, working back from IC9, I soon found that I didn't hear any hum from the input to IC7B.”

Thank you for your time. It is the latest batch though...

Hi, my first two worked fine, I need to get back to it!

Depends if you operate portable or not... In the field antenna length is no problem.. That said I am a big fan of 30m :-) Upper bands are not opened as often. 30m has no contests too :-)

No. Keep politics out of the hobby, please.

Great. I did not have those problems but it was a tight fit..

If you don't have a CW rig already, I recommend getting a QCX, paddle, straight key, and a resonant antenna WHILE you're learning CW. Getting on the air is IMHO the best way to learn CW. Ten to fifteen WPM is a great goal, but you don't have to be at that proficiency level to get on the air. By getting on the air sooner, you'll benefit by: a) being able to decode real CW code which is sometimes far from the perfect code sent by training programs, b) learn how to operate your radio for when you are ready to get on the air, and c) begin making QSO's as soon as possible, d) using the decoder in the QCX in practice mode to help see if the code you're sending is legible. SKCC is a great "slow code" group to get started with, and three exchanges are very simple and forgiving. Anyways, good luck in your CW adventure!

I would highly suggest not learning below 15wpm no matter how hard it is.

LICW great club.

@@kn6eze Thank you for the tips. All make sense. I've done 2 CW QSOs so far in the spirit of learning by doing. 73!

@@RadioPrepper OK. Thx for the advice.

Happy New Year!

It's really easy once you understand how the wires go..

There are a few of us will build these kits for you for some nominal price - sometimes less that QRP-Labs' factory assemble adder. I do it for subscribers to the groups.io forum. It would be no trouble to do a partial build: wind, install and continuity-check the inductors, then send it back to the owner to complete the rest, if they so chose.

Merci! Je voulais faire là mod du voltmètre mais n'était pas certain des contacts à souder. J'aimerais une photo du dessous du circuit imprimé avec la mod..

Why? Did the teacher want you to precut the leads? Curious.. thanks.

@@52Warlock This is rather about putting tension into solder joints when you cut leads after soldering. There is theory that such stressed joints would be more prone for further degradation ie oxidation, cracks, etc. Heard this many times.

@@52Warlock yes precut the leads, as not to stress the solder which could lead to issues in the future...

@@kamilsp7fll spot on that was what was drummed into us, especially with regards to mil spec applications.

I never did that but I guess for some sensitive applications it makes sense.

Weird. My 30m did not do that..

There's a RU-vid video out there where the guy had the problem with audio clicks...he showed the fix for it, but I'm sorry I just can't remember the RU-vidrs name/channel. But the fix is out there .

There is no stop on the pots, so hard to say..

@Radio Prepper you have to go back and forth tweeking each one in turn going around again and again until you cannot get them all any better.

@Radio Prepper if you get really lost, power down and use an ohmeter to set each pot at the middle of its range and start over. Also as you get near one end of the indicator, the range or scale for that indicator changes, up or down depending on which way you are heading, and this can confuse you if you are too focused on just the bars and don’t notice.

Thanks guys, I will try again.

@@RadioPrepper No physical stops, but those pots are approximatly 25 turns end to end. At the ends, in a quiet room, you can hear clicks as you turn. If I get confused as to where I am I just turn till I hear the clicks and then turn back 12 turns. That's close enough to the middle to start over.

Interesting, I had no issue..

@@RadioPrepper Yes Hans said that was the first he had ever heard of that. I sent him a pic of my Kx2 with it connected to and the QCX with the connection halfway from lock. He suggested removing the washer from behind the nut. That did it but I couldn’t figure out why mine was a problem. And that’s on both the 20 and 40m transceivers.

I see this with the more recent kits. The last four I've built I had to leave the lock washer out. I think the supplied nut is thicker. Don't know for sure because all my previous mini's are sold. Build/sell, repeat. :)

@@fireflaze Oh. Well good that makes me feel better. I thought it was the BNC connectors I was using. I kinda thought that it had to be either the nut or washer was thicker but Hans said that he hadn’t heard of any problems like that before. But you’re proof that something must have changed. Thanks for the info.

@@fireflaze Hi Mike :-)

You are not the only one asking, so yes!

@@RadioPrepper Thank You Gil :)

Keep me posted..

I haven't gotten back to it yet, but I need to.. Suspicion is on T1..

I talked to Hans about that, as I'd love a 2m ssb radio. Apparently the matter isn't trivial and he doesn't have the time. Hopefully someone will make one...

Not yes, I need to get back to it!

You can use three 18650 cells in serie. Use a half-wave end-fed antenna...

Hi, I think I did, but honestly I don't remember..

@@RadioPrepper OK Gil TU and may God bless you.

@@RadioPrepper Hello Gil, it is me again Ken N7KO. Just to give you an update on my question about placing a jumper to activate battery level. I ended up just removing two screws on each end panel that holds the back, Then as you know the back lifts off. This will expose enough pcb to pashion a jumper and carefully placing it in the two holes 12v+ and DVM then solder in place, tight spot but worked. Here is a short video of working on the 40 meter QCX. When I removed the back I noticed the pcb board had a bow in it, and up on inspection I noticed the bolt holding the transistors down was to long, so I ended up removing four screws and removed the board then ground off about 3/32 of the bolt. The othe two radios were fine so all I had to do was to remove the back and solder in a jumper. ru-vid.com/video/%D0%B2%D0%B8%D0%B4%D0%B5%D0%BE-1QnRtCYI3Wk.html Oh the 40 meter was assembled at the factory.

No.

Oops, did I say that? Nah ;-)

Made me laugh too...🤣

Yup, that also made me laugh a lot 😀

I have not tried the sw3b, but it does seem interesting with three bands.. There is also the uSDX..

But more current.. I am waiting for the QSX too..

Probably the light..