After the first firmware, it is no longer possible to switch on.
Hello all.
Today I finished assembling the QMX and DC on. 11.2V and max 130mA. Pressed the left rotary control and saw a consumption of approx. 117 mA. USB connected and recognised by the PC. Unpacked the firmware file and copied it to the QMX. 40m shown on the display. Unplugged everything. Then I only applied DC and tried to switch it on. Since then nothing works. Pressing the left control knob no longer does anything. Does anyone have an idea what this could be? Have I done something wrong with the firmware?
Thanks in advance.
73 Marcel DM3FAM
|
Re: QMX - smoke - another C107/Q108 failure
Stephan, I like your solution!?
Simple, yet powerful.?
I will modify my QMX accordingly.?
This should go into revision 2.
73 de SM5EIE /Gunnar?
|
Hans has promised that QMX will support AGC as a firmware upgrade, but its not available yet.
I've now used my QMX quite a few times on air for CW contacts and it still catches me out when a strong signal suddenly appears! I won't be using headphones until there is eitehr AGC or some audio level limiting implemented - for now using an external powered speaker with its own analog (i.e. quick to adjust) volume control works to get me on the air without hearing damage.
The QMX does have excellent dynamic range, but without AGC that is then reflected in a wide range of possible audio levels, so I would advise caution but that shouldn't stop you enjoying the radio.
Jon G4IVV
|
Re: QMX Shipped, panic stage
#qmx
I'm not sure I see negativity.
I see people reporting problems, people
with concerns about the design. But everything done in a rational,
intelligent, adult way.? People prepared to listen to other's
opinions, discuss their differences, and if necessary agree
amicably to differ.
Practically unique on the internet.
Thanks to everyone, particularly Hans.
Chris, G5CTH
On 31/08/2023 19:44, Stephan Ahonen
KE0WVA wrote:
toggle quoted message
Show quoted text
As someone who is responsible for many of the negative messages -
People who are having no trouble with their radio are out there
making contacts with it rather than logging into a forum and
talking about it. I bought my kit on the strength of a
recommendation from a friend who has never posted here. He's
having a great time with his kit and I can't wait to get mine on
the air with his, and when that happens I'll be too busy operating
to post here too. Any forum is going to contain a
disproportionately high number of people having problems, because
those are the people who are going to have the spare time to go
post in the forums about it.
Even though I feel some design decisions could have been made
differently, the reason I even feel the desire to express that
here is because I believe it is a fundamentally good, and
worthwhile, product with one or two things that can be improved,
rather than a lost cause. I'm sorry to have contributed to any
perception otherwise.
|
For a previous QCX, that is still unassembled, I ordered the optional AGC module with it.
An older QCX that I have, does show a need for it...a strong signal WILL make 'ya jump!!
So, I'm wondering if the newer QMX has AGC already incorporated in the design...or what
I might expect?
N E 1 ??
Dave KD2E
|
Re: Power supply recommendation wanted
Little trivia note....
HP paid the same company for dreaming up "Agilent" that
Bell labs paid to dream up "Lucent"?? Comparing the two, not surprising!!
There are many items, like an expensive 3468 DVM, where you might find the exact same
item with either HP, Agilent, OR Keysight on the front!!
But of the two power supplies I had mentioned previously, one is either HP or Agilent, and the
other is just HP....neither would be Keysight.
....Dave? KD2E
toggle quoted message
Show quoted text
On 8/31/23 12:42 PM, Jim W2JC wrote: On 31 Aug 2023 at 8:56, Shirley Dulcey KE1L wrote:
Keysight is now the company that's most like the
original Hewlett-Packard who picks these oddball spinoff company names?
imo, HP THREW AWAY their entire fabulous
brand name and market confidence when they
rebranded to 'Agilent' ...
|
Re: QMX - smoke - another C107/Q108 failure
On Wed, Aug 30, 2023 at 08:09 PM, Paul - AI7JR wrote:
I'm curious about what you propose, but that link doesn't show anything. :-(
Paul -- AI7JR
On 8/30/23 18:17, Stephan Ahonen KE0WVA wrote:
>In the end, it has to be acknowledged that you can never please all the people all the time, and have to try and strike a balance somewhere. Which is often very difficult indeed.
I suppose you know your target market better than I do, and it's presumptuous of me to think otherwise, I apologize.
>I think with my firmware changes I was able to very substantially mitigate that vulnerability but the risk is still there if extreme voltage fluctuations suddenly take place.
I think I remember reading somewhere that the control loop operates at a frequency of 1 khz?
If this is the case then the software physically cannot respond quickly enough. According to SPICE, if input voltage steps from 6 to 12 volts, with a 330u series inductor and 470u output capacitor, 1 ms is enough time for the output voltage of the 5v regulator to rise from 5v to 11v before the CPU even has an opportunity to figure out that something is wrong.
to the power supply circuit would help. At a cost of three extra parts (including a series resistor on the PWM_5V line, not pictured), a voltage excursion now immediately shuts down PWM, much faster than the CPU can react. Total BOM cost of $.10 or so?
Paul,
This is what link shows:
73
Barb WB2CBA
|
Re: QMX - smoke - another C107/Q108 failure
On Wed, Aug 30, 2023 at 10:09 PM, Paul - AI7JR wrote:
I'm curious about what you propose, but that link doesn't show anything. :-(
Damn. I'm on my phone right now and about to get on a flight so this will have to do - * Change value of D108 to 5V * Disconnect Anode of D108 from ground, instead connect to the base of an NPN transistor * Connect NPN emitter to ground, connect collector to PWM_5V * Add a resistor from NPN base to emitter (value tbd, likely 1k) * Add a resistor in series from PWM_5V to to microcontroller (also value tbd, likely 1k or less) * Repeat for 3V3 rail Now, whenever the 5V rail exceeds 5.6 volts (zener voltage + NPN Vbe), the NPN turns on, pulling PWM_5V low until the fault clears.
|
Re: Power supply recommendation wanted
I have the same "Korad" supply. It's been going strong for several years now. The supply limits voltage across its output transistor by switching between several taps on its supply transformer using a relay. I have had to replace that relay one time, I believe an inductive spike killed it. But it has otherwise been performing fine. I've used it for everything from powering electronics to electroplating and anodizing.
|
Re: QMX Shipped, panic stage
#qmx
As far as assembly goes - Yes, it is a challenging build. It's by far the densest PCB I have ever populated. You will need to be extremely diligent about avoiding solder bridges. Keep solder wick handy. Inspect all of your joints with a microscope or loupe. Many pads sink into a massive thermally conductive ground plane and you will need a hot, powerful iron with plenty of thermal mass to make good joints in them. Know how to identify a cold solder joint. The enamel on the thinner magnet wire used for filter toroids burns off just fine but the thicker magnet wire used for power magnetics will need to be sanded off. The assembly manual recommends installing through-hole caps/diodes/inductors before toroids, but I think I'm going to do the opposite with my second build attempt, I'll report how it goes. I think the density of that area will make it easier to put the big things in first, then work the smaller things in around them.
Optional steps not mentioned in the manual:
Add thermal paste between BS170 output transistors and the ground plane underneath.
Some builders of the previous generation QDX put a flyback diode across the equivalent of L502 in that product.
If you set a current limit on your power supply the first time you power up your QMX, don't forget to turn the current limit off before you transmit. :)
|
Re: QMX Shipped, panic stage
#qmx
Billy,
There is bias in the list.? People that have problems make noise those that succeed can't be bothered.
So you see the disaster stories even if its a low percentage of the actual builds..
Do you self a favor, read the assembly manual before you get it. read it carefully?
and understand the assembly procedure.
--
Allison
------------------
Post online only, please no email.
|
Re: QMX Shipped, panic stage
#qmx
As someone who is responsible for many of the negative messages -
People who are having no trouble with their radio are out there making contacts with it rather than logging into a forum and talking about it. I bought my kit on the strength of a recommendation from a friend who has never posted here. He's having a great time with his kit and I can't wait to get mine on the air with his, and when that happens I'll be too busy operating to post here too. Any forum is going to contain a disproportionately high number of people having problems, because those are the people who are going to have the spare time to go post in the forums about it.
Even though I feel some design decisions could have been made differently, the reason I even feel the desire to express that here is because I believe it is a fundamentally good, and worthwhile, product with one or two things that can be improved, rather than a lost cause. I'm sorry to have contributed to any perception otherwise.
|
SSB instead of CW in the logbook
When operating the QMX, I noticed that with CW, the CAT control sets the SSB mode in the logbook and automatically enters 59 instead of 599 in the report. That's not good if you want to take part in a CW contest with the QMX. There are incorrect entries. ? 73 Reinhard DL3AS ?
|
Re: QMX Shipped, panic stage
#qmx
Billy, Just as additional reassurance, I built mine carefully, following the assembly manual literally. Mine powered up and worked fine the first time. I love this radio.
-- 73 Michael N6QP Up in Thin R
-- 73 Michael N6QP Up in Thin R
|
Re: QMX Shipped, panic stage
#qmx
I'll add that past the Q103/Q104 short, I directly contributed to
the eventual failure of my QMX.
When I fixed the short, the hot air gun dislodged a couple of
other parts, leaving my QMX turning on, but "strangely". While
fixing that "strangely", something else happened that might have
taken out the CPU (maybe an errant clipping stuck to the mother
board.)
That problem has to be classed as my error, not a
problem with the design!
As Hans says, "You can do it!" Proceed with requisite care!
73, Paul -- AI7JR
On 8/31/23 07:14, Hans Summers wrote:
toggle quoted message
Show quoted text
Hello Billy
1) You're reading the wrong messages. There have also been
several nice reports of success stories.?
2) You also need to remember that all mailing lists have an
inherent negative?bias, in so far as people are far more
likely to post about a problem they are looking?for help
solving, than they are when everything is fine. And rightly
so, since?with 7,541 members here on this group, if everyone
posted something when they were successful, and the fact we
shipped an average 800+?orders per month in the last 6 months,
many of which contain multiple kits, we'd soon be overloaded
with emails. So keep the misery posts in perspective.?
3) Bear in mind the only known issue is that the Q103/Q104
transistors on the 5V SMPS board are a little close together
and due to manufacturing tolerances, a proportion of boards
have unfortunately got a solder bridge between the two drains;
HOWEVER, we are already testing all shipped boards for this
fault and correcting it pre-shipment if we find it.?
4) Watch my "52-tips" video?
while waiting for your QMX to arrive.?
5) If you take care and observe all the precautions
mentioned, there is a VERY high probability of success.
Remember, component and manufacturing failures are rare. It's
largely in your hands!
6) You're a Texan. Texan's can deal with anything.?
On Thu, Aug 31, 2023 at
4:48?PM N5SE < bwmoore@...>
wrote:
Hans,
Received message my QMX shipped today. Thought I would be
excited. But instead, I am reaching panic stage. With all the
misery I have read in the last week, I figure my chance of
ever getting it to work is somewhat less than zero. Guess I am
looking for a little assurance.
-- Billy (N5SE)
N5SE
Billy Wayne Moore
7066 Shady Knoll Ln
Willis, TX 77318-6324
Phone: 936-537-2975???
|
Re: QMX Shipped, panic stage
#qmx
Billy,
stay brave...
... take your time and you will get it done...
I am one of those who? - read the manual twice - took my time to build - did it step by step and everything went well!
No surprise with Hans excellent Manual and additional hints from this Forum...
There are to many reports about Problems, but you probably know: "A bad message is told/forwarded 7 time more offen as a good one"
(Hopefully understandable as i am not a native english speaker)
Take your time and enjoy the build...
73 Alex, DK4FT?
Billy,
You can do this!? Just be careful during assembly to 1) remove all the enamel from the toroid wires before soldering, 2) check the continuity between VCC, VDD, and +12 against ground prior to first power up, and 3) use a current limited supply until you're up to full voltage (9 or 12 volts).? Also, be careful when trimming wires on the bottom of the board.? I accidentally nicked C526 when trimming enameled wires from T507, and had to find and replace this capacitor.?
Enjoy this build, and take your time.
73,
Walt - KK4DF?
|
Re: QMX Shipped, panic stage
#qmx
Billy,
as well as watching Hans' video, maybe look for the pinned comment that lists all the tips and what time they appear on the video.
I plan to have this list handy when I start my build.
73, Steve.
|
Re: QMX Shipped, panic stage
#qmx
On 31 Aug 2023 at 6:48, N5SE wrote: Guess I am looking for a little assurance. -- Well, you had at least two VERY HAPPY builders reporting in the emails today ... don't be so negative !! Follow the instructions carefully and either use a ZM-2 or equivalent manual tuner to tune the antenna before going full power and many, many people have had good results ... remember, a chat group like this draws more calls for HELP than praise for success. Jim w2jc
|
Re: Power supply recommendation wanted
On 31 Aug 2023 at 8:56, Shirley Dulcey KE1L wrote: Keysight is now the company that's most like the
original Hewlett-Packard who picks these oddball spinoff company names? imo, HP THREW AWAY their entire fabulous brand name and market confidence when they rebranded to 'Agilent' ...
|
Re: QMX Shipped, panic stage
#qmx
Billy,
You can do this!? Just be careful during assembly to 1) remove all the enamel from the toroid wires before soldering, 2) check the continuity between VCC, VDD, and +12 against ground prior to first power up, and 3) use a current limited supply until you're up to full voltage (9 or 12 volts).? Also, be careful when trimming wires on the bottom of the board.? I accidentally nicked C526 when trimming enameled wires from T507, and had to find and replace this capacitor.?
Enjoy this build, and take your time.
73,
Walt - KK4DF?
|
Barb WB2CBA
Reinhard Gr?nz
Michael N6QP
Paul - AI7JR
GM0HUU Steve