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Re: Suspected faulty rotary encoder QMX Rev 2 80-20m kit build
Hi Bruce
Thanks for your assistance. I have measured the voltage and I can't get the expected voltage while the buttons are pressed. The only correct voltage I get is with no buttons pressed. However, I have already measured the grounding between connectors, buttons, and encoders and I have a continuity. To what grounding do you refer exactly? I have carefully soldered all components applying a lot of heat as recommended. Anyway, I can't get the indicated voltage if I push the buttons. It seems very hard to identify the problem. Best 73 de I1MDQ Nino |
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Re: Suspected faulty rotary encoder QMX Rev 2 80-20m kit build
Nino,
Sorry that it still doesn't work properly. My suggestion is to find someone else (local ham - in your local club, maybe) to look at it. A fresh approach may turn something up. Good luck! -- 73, Dan? NM3A There are moments when everything turns out right .... Don't let them alarm you; they pass.? -Jules Renard |
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Re: Harmonics of QMX high band on 30M
#qmx
About an inch of attenuation. I pick up the signal with a loop close to the dummy load. I said I was a newbie ;)? Not very scientific!
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Re: Harmonics of QMX high band on 30M
#qmx
How much attenuation between the TX and the TinySA??
Looks like TinySA input overload. -- Allison ------------------ Post online only,? direct email will go to a bit bucket. |
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Harmonics of QMX high band on 30M
#qmx
Hi all, I have measured the harmonics of my QMX high band where I have sacrificed 11M for 30M. As I'm a newbie on tinySA I want to ask the experts (you) if the screenshots I'm linking to below are reasonable and in the ballpark.
Screenshots from tinySA -> tinySA-App v 1.1.20.1 QMX hig band rev 2 @ 12V |
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Re: Qcx Mini as a 6 Meter CW Beacon
John,? that is great news.? POTA is super popular.? I have been in touch with? Allen for some of his activations.? Recently I ran into him running a frequency in the CWops CWTs and doing very well. It is a great feeling for me to see you and others I have met in CWA enjoying? amateur radio and especially CW operation. Kudos to you on helping out you club with the QCX build.? I expect you will find a fine willingness to help among the QRP Labs groups.io. Happy New Year! de Charles K5KXJ
On Monday, January 8, 2024 at 12:23:32 PM CST, John Olsavicky <kc3pby@...> wrote:
Well Hello, Charles, I didn't expect to hear from one of my advisers from CWA. I hope you are well. I've been hunting pota activators and often make contact with Allen from our class. CW has become a daily activity since I started hunting Parks on the Air. It's so much fun once you just dive in and start sending on the air. This is my second QCX Mini kit and I'm hoping I'm up to getting it to transmit a nice clean signal on 6 meters. I bought this one to provide my radio club with a replacement for an ancient rig that's been operating as a 6-meter beacon for many years. I'm hoping someone in this group can give me some insight into adapting this great little radio for 6 meters. My first kit was for 20 meters and I finished it after this past Christmas. I was very impressed with the engineering of the build. Hans did a beautiful job fitting so much into a very small package. I took my time and enjoyed every minute of its construction.? |
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Re: QDX finals modification, imbalanced heating
I didn't get to the reinstall yesterday?but should have it done this week, hopefully surgery will?be a success! I did receive the TO-92 hat heatsinks; they arrived quickly. They're not so great, but I will plan to put them on the new finals with some thermal glue. There's plenty of room for everything to fit inside the case, just have to be careful the heatsinks don't slip down and short anything. I'll try to get some careful heating measurements before and after adding them. It would be good to also try removing the middle heatsink to get more careful before/after measurements, but I may not mess with that in the end as just getting this QDX back into a working state?feels like my priority. Thanks again! On Mon, Jan 8, 2024 at 11:00?AM Tony Scaminaci <tonyscam@...> wrote:
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Re: QDX finals modification, imbalanced heating
Hi Peter, Restoration of balanced signals into IC5 pretty much confirms it was damaged to some degree. Put ?in a new chip and check for balanced signals at both the inputs and outputs of IC5 before you add the new finals. Have you received the transistor caps? It¡¯ll be interesting to see how much they reduce the PA temperatures. JZ¡¯s analysis of package and lead frame heat removal seems to justify adding these caps. Question: with the caps installed, will it still fit inside the closed case? Tony - AC9QY On Sun, Jan 7, 2024 at 1:45?AM Peter Li <chinasaurli@...> wrote: I removed IC5 pretty carefully, but apparently I still put too much heat into the finals as they appeared to be drawing too much current again. I removed them and no longer see imbalance at the input to IC5 at least. I'll do some further tests and if everything looks okay I'll try putting a new IC5 and fresh set of TN0110 on tomorrow. This board has been through a lot :|. |
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Re: Qcx Mini as a 6 Meter CW Beacon
Hi Giuseppe,
It is great to hear of your success using the QCX Mini on 6 meters. I would like to know if you have any advice or comments about how you were able to wind the toroids and what other modifications you made. Did you run into anything that would be helpful for me to know as I try to duplicate what you have done? |
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Re: QMX- High Power Output at 12 Volts?
¿ªÔÆÌåÓýMike,Any screenshot of Drain waveform yet, it would be most interesting. Also output on dummy load.? 73 Ross On 8 Jan 2024, at 14:54, ok4rm <radio.miskovice@...> wrote:
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Re: Next QMX Firmware Version - What to Expect?
On Mon, Jan 8, 2024 at 12:53 AM, Hans Summers wrote:
If I had a date, I'd already have the firmware ready, and I'd already have released it...Pretty much what I tell my customers.? I'm an aircraft mechanic as a day job.? Someone says, "my airplane won't start, when will it be ready?" and all I can tell them is, "I'll let you know when it is done."? It is unsatisfactory but really, you don't know until you know. Happy New Year! Joshua |
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Re: Qcx Mini as a 6 Meter CW Beacon
Well Hello, Charles,
I didn't expect to hear from one of my advisers from CWA. I hope you are well. I've been hunting pota activators and often make contact with Allen from our class. CW has become a daily activity since I started hunting Parks on the Air. It's so much fun once you just dive in and start sending on the air. This is my second QCX Mini kit and I'm hoping I'm up to getting it to transmit a nice clean signal on 6 meters. I bought this one to provide my radio club with a replacement for an ancient rig that's been operating as a 6-meter beacon for many years. I'm hoping someone in this group can give me some insight into adapting this great little radio for 6 meters. My first kit was for 20 meters and I finished it after this past Christmas. I was very impressed with the engineering of the build. Hans did a beautiful job fitting so much into a very small package. I took my time and enjoyed every minute of its construction.? |
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Re: Suspected faulty rotary encoder QMX Rev 2 80-20m kit build
Nino,
if you measure the voltage on the control board connector, at the point S on below to ground on one of the connectors,?you should see: No buttons pressed 3.3v
left button? pressed 2.0v
right button pressed 2.5v
right encoder pressed 2.8v
?
Connector, from top
o o o o
o S o o
?
If you don't get these voltages you likely have a grounding connection problem.
These buttons get their ground through the inner ground layer and need a fair amount of
heat and solder to be completed.
?
Let us know what you see.
Good luck,?
73
Bruce, KG8IW
?
?
?
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Re: Suspected faulty rotary encoder QMX Rev 2 80-20m kit build
Hi Daniel
Thanks for your information but I can't still find the fault. I have very carefully checked all connections of the control board and performed an accurate continuity test and all is fine. Continuity between control board parts and connector outside pins is OK. For now, I can only suspect something wrong with the main board (maybe some faulty part) because I can't think of any other possible issue. The right encoder button and the right tactile button when pushed don't activate the right firmware function and both cause the need to cycle the power because the shut-down function becomes inactive. I have built successfully many kits including QCX ,QCX plus, and others even more complicated but I'm now really at a dead end. It is a pity because all tests went well, and TX power and RX are within an acceptable range meeting the required expectations but this problem makes the QMX almost useless for the moment. Best 73 de I1MDQ Nino |
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Re: Next QMX Firmware Version - What to Expect?
Hans, thanks for the update / reply. Certainly understood about the long hours - I can hardly imagine what your daily routine must be like!
?The CW glitches aren't much of a bother to me, as I use a bug most often and on the rare occasion that I go with a keyer it is via my WinKeyer USB. As to the AGC issue, I find that keeping one of the headphone pads off of my ear provides most of the protection I need. A particularly loud station is unpleasant, but certainly not deafening with this method. Low band QMX working well, 1/3 of the way done assembling my high band unit and taking my time. :-) -- Jim / K7TXA Eagle, ID SKCC 10447C BUG 301 |
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Re: Qcx Mini as a 6 Meter CW Beacon
John. Great to hear you are doing a QRP Labs project, and I hope you have great success with the 6m beacon. I have just finished a QMX Rev1 kit and go it on the air late last week.? These kits are remarkable designs and fun to build.?? Wishing you success, Charles K5KXJ
On Monday, January 8, 2024 at 05:58:49 AM CST, John Olsavicky <kc3pby@...> wrote:
I just ordered a QCX Mini kit and plan to experiment with it to get it to transmit a 6-meter beacon in the US. Has anyone had success doing this with the QCX kits?
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Re: QMX- High Power Output at 12 Volts?
Hello, I have a similar experience (kit dispatched on 7th December from QRP Labs). Probably the lot of BS170's delivered in the end of 2023 happens to have lower threshold voltage.?
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The output depends on antenna SWR and maybe th frequency. From fully charged LiPo battery (12.6) the ouput on most bands seems to be 6+ watts into dummy load. With real antenna it varies depending on SWR and perhaps other factors - at some bands it is 4-5 watts, at 7 MHz it is roughly 6 W ("measured" by SWR meter and the built-in diagnstics). Perhaps in a future version of firmware there will be possibility to adjust bias voltage to limit output to 5W max. From the dB perspective +1 W makes no difference, excess heat was not observed, but I would be happy to keep the output power within the recommended limits. Anyway, if any of the BS170's blows, I have plenty of them in my spare parts box, so in principle this is no big deal. 73 Jindra On Sun, Jan 7, 2024 at 09:09 PM, John Z wrote:
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Re: Next QMX Firmware Version - What to Expect?
I really welcome the prioritisation on the keying glitches and AGC Hans, as the former means I tend not to use my QMX currently.
I know you will resolve them, and from my point of view I will then have a rig I can trust to use the way I wish (mainly Iambic at 20wpm +). Looking forward to future iterations as they become available.? Best 72 Daimon. G4USI |
Joshua KJ7LVZ
Bill, N4QA/QRP
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