Mike. Probably all you need to do is calibrate the reference oscillator frequency. The 27 MHz crystal reference is defaulted to 27,004,000 and needs to be adjusted. This is menu item 8.5. If that reference is indeed at the default value try changing it to 27,000,349 and see if that gets you closer. Good luck
Ron
Hi all,
?Today I went to activate k-1168 and the vfo said 14,050,50. RBN clocked me on the pita page at 14,052,40.? I checked RIT and it was set to 0.000.
I don't have a taco but did tune without issue and in the past have had no probs contacting people in the past.??
Any thoughts on what to check?? Do I need to return?
TIA,
Mike/KF5RUO
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Re: QMX won't power off and odd voltages on Q103
Thank you so much for your interest in my problem (s).
I think I have more than one problem. The unit won't shut down by pressing left encoder. I have checked and rejected the encoder connections to the board and have made sure they are not electrically touching the encoder body. With probes connected to pins 2&4 of the six pin header and pressing the left encoder, I get a buzz on my multimeter (continuity). ?I reflowed the 6 pin header on control board and now they is a mess of burnt roisin. I can measure continuity from the pins on control board to the main PCB connections on the bottom. I most definitely have an issue. I am not sure which pins are which on the female header on the main PCB so I could short them temporarily in hopes of getting the unit to shut down. If I can, then I my shut down problem is on the control board.
On to voltages on the PS boards.
If I set my bench supply to 8v, 225ma, I get the following. (When on, voltage drops to 5.25 and 223ma)
? ? ? ? ? ? ? ? ? ? ? ? ?ENCODER OFF ? ? ? ? ? ? ?ENCODER ON
5v board
Q103 Gate ? ? ? ? ? ? ? ? 7.92 ? ? ? ? ? ? ? ? ? ? ? ? ? ? 0.0?
Q103 Source ? ? ? ? ? ? ?7.69 ? ? ? ? ? ? ? ? ? ? ? ? ? ?5.1
Q105 Gate ? ? ? ? ? ? ? ? ?7.92 ? ? ? ? ? ? ? ? ? ? ? ? ? ?0.0
Q105 Source ? ? ? ? ? ? ?7.69 ? ? ? ? ? ? ? ? ? ? ? ? ? ? 5.14
3 v board
IC 101 G ? ? ? ? ? ? ? ? ? ? 0.0 ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? 0.0
IC 101 S ? ? ? ? ? ? ? ? ? ? ?4.7 ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? 3.2
Measuring the headers of the 5v board:
OFF
1=7.93 (leftmost) ? ? 2=0.0 ? ?3=8.0 ? ? ?4=0
ON
1=5.25 ? ? ? ? ? ? ? ? ? ?2=1.26 ? ?3=5.28 ? ?4=2.375
3v board:
OFF
1=0 ?(leftmost) ? 2=0 ? ? ? 3=0
ON
1=0 ? ? ? ? ? ? ? ? ? ? 2=5.08 ?3=5.1
D103 ? 2.426 when unit on instead of -3.3V ?as you suggested.
Grounding the 78M33 (middle pin) turns the unit off
I am confused and do not know what should be my next step. I keep doing the same thing over and over and getting the same results which is the definition of insanity. I hate to give up, but I am stumped.
Thanks for your thoughts
Phil
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What size is this SMD 47μh choke?
--
73
Karl
KI4ZUQ
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Re: Power supply recommendation wanted
All my co-workers were issued 1740 or 1741A scopes. I was working
on higher frequency stuff, so I lucked out with a 275Mhz 1726A
scope..with the LED display riding on top. Loved that scope, and
was able to keep it after I left HP/Agilent...but time marches on,
and scopes got smaller. Sold it for a much smaller Tektronix scope
a few years ago!
....Dave
On 8/31/23 6:47 PM, Denny WY2A via
groups.io wrote:
toggle quoted message
Show quoted text
Dave, I was checking the auction site, and you weren’t kidding.
Quite a range and some ambitious pricing. I’ll keep looking.?
…and I’ll keep your contact information for the time I build up
the courage to repair the power supply of my HP 1741A scope.?
Denny
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Hi all,
?Today I went to activate k-1168 and the vfo said 14,050,50. RBN clocked me on the pita page at 14,052,40.? I checked RIT and it was set to 0.000.
I don't have a taco but did tune without issue and in the past have had no probs contacting people in the past.??
Any thoughts on what to check?? Do I need to return?
TIA,
Mike/KF5RUO
|
Re: After the first firmware, it is no longer possible to switch on.
Did you check the 16 soldered pins on the USB-C connector for GOOD soldering ? The GCT USB4085 part has very short pins for a 62mil PC board so they may not be soldered to the via barrel to make good contact with the various layers used. The result is an "iffy connection" which you don't want for USB-C use.?
73 Kees K5BCQ
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Re: Power supply recommendation wanted
Dave, I was checking the auction site, and you weren’t kidding. Quite a range and some ambitious pricing. I’ll keep looking.?
…and I’ll keep your contact information for the time I build up the courage to repair the power supply of my HP 1741A scope.?
Denny
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Re: #qmx QMX and waste heat from the finals
#qmx
Here I am obsessing about putting thermal compound on the outside of package, when duh, of course the leads are going to be the lowest resistance path for heat out of there.
That leaves the question of where the heat goes once it's in the ground plane. Maybe most of it gets conducted to the enclosure, and out the shielding of your antenna cable, via the BNC?
I've got some silicone thermal pad, thick enough to fill the gap between the bottom of the PCB and the enclosure, I wonder how effective that would be at pulling heat out to the enclosure too.
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Re: After the first firmware, it is no longer possible to switch on.
A reset is mentioned on page 67 of the instructions. That worked. I copied the firmware file again and I can now start the QMX again and again.
Only I cannot do anything else. The push buttons and encoders do not work properly. The right encoder can be turned and shows 1-12 in the second line. That's all you can do. Does anyone here have any ideas?
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Dear group,
While convalescing with all the ills I have acquired since July 4th, I decided to dig into my kit pile and spend the time building the neat kits that I had bought. ? While working on a QDX Rev 3, I was building along and noticed that L11 looked funny. ? It was broken in half. ? I may have done it or some shipper may have.? I am not concerned with "who killed John". ? I just need a part. L11 is a SMD 47uh choke. ? I thought I had a "hanger queen" QDX but I think someone else got it when they need a part.
So I need an SMD 47uh choke for my QDX.?? Does anyone have a stock of them that would part with one or two??? I will pay postage etc. as required.
and if you bought them I will pay for two.? I just need the part and don't think that DigiKey? would be happy for a order and the postage would not be pretty.
Thanks for the time and I hope I can come up with one of these so I can get my QDX running.?? Address is good in QRZ .
73 Dave WA5DJJ
SUPER GRABBER
?WEBSITE:
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Re: After the first firmware, it is no longer possible to switch on.
Maybe set the current limit to say 250ma.
Roger
8P6RX
Get
On 31 Aug 2023, at 17:21, Marcel < dm3fam@...> wrote:
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
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Re: QMX - smoke - another C107/Q108 failure
On Thu, Aug 31, 2023 at 04:00 PM, SM5EIE /Gunnar wrote:
Simple, yet powerful
I feel like this should be the slogan of the entire QMX project
I will modify my QMX accordingly.
You must be more confident in your dead-bug construction skills than me
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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
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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?
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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
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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.
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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
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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' ...
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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
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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.
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Ronald Taylor
Karl
Barb WB2CBA