OK, folks.? This is going to be the most stupid thing you've heard all day.? Maybe all week.? Or maybe in your lifetime.? Bear with me.? I have some 'splaining to do.? This will be a long read.? And I need some advice.?

I found a great little inexpensive plastic enclosure that the QCX fits nicely in.? That will be the subject of a future post, however.?

Once I had the QCX CCA mounted in the enclosure, I found that the tab of the 7805 regulator was too tall and the enclosure lid would not fit.? I removed the regulator from the CCA and looked at the leads.? They are thicker near the body of the regulator, necking down into a smaller diameter about 3/16 inch away from the body.? I took an emery board and carefully filed the leads down so that they were a uniform thickness all the way along their length.? This allowed the regulator to slip into place flush with the CCA, which gave me enough headroom to close the lid on my enclosure.? Neato!? Just what I was hoping for!? So I soldered the regulator into place on the CCA...? BACKWARDS.? Yep.? I actually did this.? And I didn't notice it.? Now, I'm no noob.? This ain't my first rodeo.? I'm a Senior RF/Microwave Test Engineer with 38 years of experience at a major aerospace company and I've been a ham for over 40 years.? I was a bit distracted due to non-radio related matters.? Still, this kind of thing just doesn't happen to me.? I'm usually very, very thorough!? Well, as I said, I didn't notice the mistake.? I powered up the QCX.? The display lit up for an instant, then the 1 A fuse in my power lead failed (note to everyone -- ALWAYS use a fuse in your power lead because you never know when something unexpected will occur).? I started looking for a cause, and I almost immediately noticed the incorrectly installed regulator.? DUH!!!? I removed it again.? Unfortunately, the plated-through vias pulled out of the board.? Damn!? I looked over the board and it looked like it should still work, so I went ahead and soldered the regulator back into place, correctly this time, and powered up the QCX again.? The display lit up.? I had audio in the headset.? I hit the key, and I had full transmit power.? The VFO was right on frequency.? The CW note sounded clean in my K3's receiver.? I was overjoyed!? That is, until I realized that I didn't hear any signals coming in on the QCX.? I switched the antenna over to the K3, and the pan scope showed strong signals all across the band.? The QCX wasn't hearing any of them.? I switched K3 into my dummy load, dialed the K3's transmitter down to 0.1 Watts, and hit the key.? The QCX did not hear the K3's signal.? CRAP!? I set up the QCX to allow me to run through the alignment checks again.? It ain't hearing itself.? No 700 Hz tone.? No received signal at all.? I get good audio, and it has the characteristic sound of the 200 Hz filter.? Everything seems to be functioning correctly.? But the receiver is not hearing a bloody thing.? What the devil did I kill?? I can't believe this!? I was sooooo close to being all finished with this project, and now it's broken!?

Anyone have a suggestion as to where to look for the failure?? This one has me stumped.?

73/72,
Dean K5DH? --? very depressed!
20m QCX msn 612

Actually, I am thinking this can be resolved in firmware:
If you are running is straight key mode (Menu 4.1 Keyer mode: Straight), then the QCX must just ignore the ring or "Dah" input...
Only when you enable other keyer modes does it use the ring input for dah.

74, Nick VK4PLN

I added a mono jack on mine or you can use a stereo to mono adapter to use a straight key or external keyer. A mono plug inserted creates a short.

?

I recently built a 1-watter QRP kit that uses a "smart jack" - it automatically places the keyer in straight key mode when a mono plug is inserted. Something like that would be nice with the QCX.

Steve, N4IAG

?

Hi Robin.
I have experienced this with other setups as well. A mono plug in a stereo socket will cause the ring and ground of the socket to short, thus keying a "dah".

Its simple to a stereo plug...

Cheers.

I have built #585 and the receive section is working along with the display and the sub menu items. The rig aligned as per the manual. The keyer and side tone are working.

?

However, the transmitter is not working. CLK0 and CLK1 are displaying quadrature wave forms. But here is no CLK2 output. I isolated IC1-pin 6 and still no output. So I decided to strip out IC1 and its associated components and substitute an Adafruit 5351 breakout board (didn’t realize that QRP Labs also has a similar breakout board). I changed the 27mHz crystal from the QCX to the Adafruit board in place of the 25mHz SMD Adafruit crystal.

?

CLK0 and CLK1 are operative but still no CLK2. I disconnected pin 6 again and still no output. Since the same condition appeared in both approaches I’m suspecting IC3 may be faulty. I do have a second Adafruit board and could try the same procedure to see if an unconnected CLK2 pin would have an output.

?

Any suggestions ?

?

73, Dave NE5DL

Shirley KE1L wrote...

Most of the toroids are easy...

Thanks for the encouragement. I started with the
80M QCX. I hear those ones are easier to wind - hi!
I think I'll wind the toroids for the 40M version
first (half way done) before going back and finishing
off the first one.

--
73 Keith VE7GDH

Dave G3WUN wrote...

I don't know if you are happy with SMD construction
but I feel it is fine even as a first SMD project.

It started some months ago when I viewed a view videos
that made hot air tools & SMDs to be not quite as difficult
to use as most of us think they are. I went looking for
an SMD kit (I've never made circuit boards... well, not
successfully) and I found the BITX-40. However, all the
SMD parts are already mounted on the board. I have one
and I'm about to do a few mods to it.

It was on the BITX support list that I heard about the
QCX. I had probably been to the QRP Labs site before, but
hadn't ordered anything prior to the QCX. I don't have
one on the air yet (enclosure, toroids) but I'm getting
close. It would be "full circle" to actually put an SMD
kit together. So far, I've only worked on some practice
kits (varying degrees of success... tiny parts were very
difficult, larger parts easy, smallish ICs (actually just
one so far) a zillion times times easier than I thought
it would be. The 80M and 40M QCXs have been fun to work
on and they will force me to brush up on my very rusty CW.
Afterwards, I will be on the look-out for something using
SMDs. The Proficio SDR transceiver looks interesting.
Thanks for your comments on the MultusSDR kits.

--
73 Keith VE7GDH

Come to think of it...this is QRP Labs and about the U3S kit.Lets remember what QRP is ...
QRP operation is not 20,30.40.50+ watts like QSO modes are usually abused.When I say abused I mean 30+ watts on 20/30m or any other band that will work fine @ 1 watt.After all,what fun is it any other way? May as well make a phone call and get the same thrill of it.I know I can setup FT8 right now,pump in 30 watts and make QSO`s all day long on 20/30m...but I find that boring and too easy.I can do the same thing with PSK63...just add power :)
My point is simple.Using the "QRP" Labs for an FT8 beacon will never interfere with QSO`s since it is such low power.Those of us using the QRP kits have no real choice but to move where the receiving stations are.Again,JT9/JT65 and all the rest are abandoned soon as a new mode comes out.What good is running a QRP beacon if there are no receiving stations to spot it? All I have to do is look on PSKREPORTER and run through the modes to see who is actually there.So far,looking grim except for FT8.Sort of forces QRP enthusiasts to also migrate to where the most population is right?
Not sure about anyone else,but finding spots from a 20mw signal feels pretty good.
However...why not more operators utilized 2/6/10/70cm bands and drop 50 watts into that? Sounds much more challenging in my opinion and achievement.
MSK144 was doing really well for some time...but now looks it too has dimmed out.
Just my opinion and nothing more.
Jim

Hi Keith,

There are about 30 SMD devices including two 8-lead ICs (not as close a lead pitch as the FST3253 as used in QRP Rx ).? R's and C's are 0805 , with four SMD can-type electrolytics.? The PCB board is quite large so components aren't packed too closely.? All components are clearly packed and labelled.

Obviously I don't know if you are happy with SMD construction but I feel it is fine even as a first SMD project.

Hope that helps.

Regards

Dave

G3WUN

'Test equipment is good'

Dave G3WUN wrote...

I built the mWattmeter II (kit) from MultusSDR :

Just curious... are the the MultusSDR kits just the
circuit boards and parts... i.e. you get to solder all
of the SMD part on the circuit board? TIA

--
73 Keith VE7GDH

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Most of the toroids are easy. The only challenging one is T1; it takes
a bit of work to get all the wires in the right holes.

Vernon VE1VDM wrote...

My kit should be here in a day or two so will be
printing it off soon...

I didn't print any of the manuals. I just opened them up
on a tablet (iPad) and used it while working on the QCX etc.
I'm about half way through the second one, but haven't wound
the toroids for the first one yet. Procrastination? Fear?
I'll decide tomorrow.

--
73 Keith VE7GDH

But how intrusive would an FT8 beacon be with such low power? Everytimne a new mode comes out,all rush to it while other modes are left for dead.
See JT9 activity or Opera...slowly going away.
I find JT65 horribly intrusive on 30m...these guys do not care where they are QSO`ing. Directly over WSPR in most cases.
RTTY even worse.
The shocking part is I hear JT65 with no antenna connected...how much power do you need?
I sometimes wonder if most users even acknowledge activity on the waterfall before transmitting?
WSJT-X at least prevents TX out of frequency...too much junk software spreading around out there in my opinion.
Jim

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Good idea John, I have a few trimmers in the junk box that will do the job and it might give an idea how much extra inductance is required so I can calculate the number of turns required Thanks Robin G4DNP