Re: QMX+ PA Voltage marginally low
Thank you for the verification, Hans.
I will look forward to the calibration function when time allows.
73 Trevor G6PSZ
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Re: QMX+ build: so close, and yet....
Hi Michael,
?
that’s great that it is alive. ?Congratulations on that part.
?
look at all of your soldered joints under magnification and a bright light. ?Look especially at T501, the output transformer. ?If you didn’t scrape the enamel off the wire and solder those well it would exhibit this problem. ?The same for L502. ?Remember that the rig will work correctly if all parts are in the right place and soldered well. ?It’s rare that a part is defective.?
good luck
?
--
73
Jeff Moore
W1NC
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Re: Pwr output dramaticly decrease with higher Freq. from 6 W to 0W, for 160 to 20Mc
Hi Don, mni tnx for your answer. Yes I also think the driver SN74ACT08D is under suspicion and I will replace it
73, Guido HB9BQB
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Re: Pwr output dramaticly decrease with higher Freq. from 6 W to 0W, for 160 to 20Mc
Hi Greg, mni tnx for you answer. Yes I also think the driver SN74ACT08D is under suspicion and I will replace it
73, Guido HB9BQB
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Re: Low power output from new QMX
mine is close,
2,5w on 20m;
1,8w on 17m;
?
My SWR is higher
?
73 Luis
CU2IJ
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Re: Using .33mm/AWG#28 for everything in the QMX+?
On Sat, Aug 31, 2024 at 03:37 PM, Joe Lokaj wrote:
See /g/QRPLabs/message/128803 . I plan to do the same when I get to that step of building my QMX+ to avoid one of the challenges I had building my QDX-M.? 73 Joe KA1ZNA
?
Yes, the only exeption I remember are the single turn coils in the T507. Eveything else seams to be in .33mm wire.
?
Good luck,
Luis
CU2IJ
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Re: Still no output on QMX
Yes, I just rechecked my dummy load to be sur and, it measures 50.1 Ohms.
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Re: Still no output on QMX
Looks that way but if you look at the screenshots, you can see I'm using a 9V supply.
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Re: #QMX IC402 issue in combination with 50W PA?
#qmx
Hi Stan,
?
thanks for your comment.
I do have a newer revision with D516 already installed as SMD.
?
?
KR
?
Dirk
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Re: Broken STM32 pin to LCD
Thank you so much for the tweak; I really appreciate it!
I'm curious, what would/could be added that would require the 8-bit mode?
I have some ideas I wanted to try but I consider them "stretch goals" and so so far out that I don't want to put them on paper (or electronic equivalent) until I am way past much higher priority things and until I have experimented a lot and know what's possible; so perhaps nothing may ever come that requires 8-bit mode, perhaps it may, I don't know yet.?
The other thing is speed, it takes twice as many write operations to transfer the data in 4-bit mode compared to 8-bit mode. Right now there is nothing that requires higher speed but the 8-bit write mode does make things faster overall and something may benefit from that in future.?
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Re: QMX+ PA Voltage marginally low
Hello Trevor
Marginally low PA voltage is not considered a problem. It's acceptable. There's device to device variation. In the future?I will include in the firmware a calibration function that can measure and adjust for device variations in the PA modulator.? On Wed, Sep 25, 2024 at 6:16?PM Trevor Shackleton via <trevorshackleton= [email protected]> wrote:
Hello,
I have built up my QMX plus purchased at the Telford rally and have a question to check.
Using a PuTTY terminal to access Hardware tests, Diagnostics, under transmitter; the Voltage (on the PA) is borderline low. This is consistent across all bands.
The build is for a nominal 12V operation.?
Example for 40m operating into a dummy load. The PA voltage reads jumps between 9.7 Red and 9.8 Green, while the input voltage is read as 11.6V or 11.7V. Should I be concerned about this or is about 2V drop over the modulator considered acceptable.
Best regards Trevor G6PSZ
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Re: Production seems to have slowed significantly
Hi Ian, all
> Why such a slow down?
According to my records for the last 6 months, there has not been a significant slow-down. Remember September isn't over yet. September production was certainly?lower than July/August.
Reminder, the waiting list is updated daily here:?
The table below shows September up until 25-Sep-2024 so it is an incomplete month. The table shows the number of new assembled kit orders, and number of orders shipped. Note that this is the number of orders, not the number of kits (some orders are for more than one assembled radio, so the number of assembled radios per month is higher than what is indicated here).?
Month? ? ? ?New? ?Shipped -----? ? ? ?---? ? ? ?--- March? ? ? ?170? ? ? ?252 April? ? ? ?153? ? ? ?210 May? ? ? ? ?236? ? ? ?154 June? ? ? ? 185? ? ? ?177 July? ? ? ? 157? ? ? ?286 August? ? ? 140? ? ? ?250 September? ? 93? ? ? ?124
Of course there is some month to month variation, there are a lot of factors involved. Factors include (but are not limited to):? - We have 11 full-time employees here (plus XYL and myself). All of our team are capable of building transceivers. Several of them are specialized to certain tasks: Shipping, Testing/calibrating, Flashing bootloaders and testing boards, Fixing issues (technician). If for some reason their specialized tasks are complete for the day then they default back to building kits.?
- Of course from time to time someone leaves, someone joins, it takes time for them to get up to speed etc.?
- In April, May, June a lot of resources were diverted to kitting efforts in preparation for Dayton and Friedrichshafen hamfests. It takes a lot of time and effort to pack a thousand QMX for example, all the little parts have to be sorted and carefully counted out, checked to try to make sure there are no errors, etc.
- In July and August we had several extra summer intern employees on and off, apparently collected from around the neighbourhood, uni or college students etc. in their summer holidays. Sometimes I'd look out of my glass office and I'd?be like, who the F - there's some new teenager, I could sort of half recognize from having seen around the area some years ago when they were smaller and back in the days when I actually occasionally got out of the lab and saw the light of day. Hi hi. Anyway all good work experience for them and they need money.?
- July/August/September are also a time each year when order volume noticeably decreases, and this also frees up resources from kitting/packing/FedEx-DHL'ing?to build radios instead.??
- In May/June there was a burst of new orders for the QMX+ (which was launched at Dayton in mid May) and it definitely takes more time to build one of those than it takes to build earlier kits like QDX. As we are now shipping kits that were ordered on 21-May-2024, this is very soon after the QMX+ launch and at that time people were mainly ordering QMX+.
- Another reason production is a little lower in September is that several employees chose to take annual leave holidays around this time; and we also had two employees who were each away for one week due to sickness.?
Generally it's hard to size a team; one cannot hire and fire on a whim; there are of course human factors, also legal ones (labor law), financial, time to train people, blah blah. So there's always going to be some ebb and flow in the waiting list size and production rate.?
I'm also attaching the chart of waiting list length since we started producing Assembled radios as well as kits, which was November 2018. At the end of last year we peaked at 906 waiting orders for assembled radios. Right now the waiting list is 542 orders, which is the lowest it's been in 16 months, since before the QMX launch at Dayton last year in May 2023.
73 Hans G0UPL
Between August and Sept I moved up about 200 spots, and this month I'm currently trending to be closer to ~100 for the same period. At first it looked like I was going to get it by Halloween, now it's inching closer to mid December(Way too cold to go out and POTA in Canada).
Why such a slow down?
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Number sent.?
i think your build looks great. From what i saw yesterday i figure you’ll be able to tweak better results than me. Your Bpf should also be squeezable. If you look at mine the windings are very close. The peak for 80 40 and 60 is shared so right now on yours forty gets the cake and 60 is a little down (not much) ?80 is a compromise. If you like where mine is you could simply start by squeezing turns on your Bpf ?inductor and r re sweeping. Also keep in mind your use. 40 is a work horse. 60m one you use a lot??? Etc. but I think you wound ?the most configurable way where I took a chance and wound mine the way I did so it would stay consistent. It’s not moving around. Chat more on the phone. I have to get back to sleep.?
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Re: Still no output on QMX
The high-band powers look like you wound the transformer for 9V but are running with 12V.
Hi Ludwig, I have some output numbers for you.
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60M-<.5W
40M-<.5W
30M-<.2W
20M-9.9W
17M-8.4W
15M-5.5W
?
Do you have an idea why there's very little output om 60M-30M and too much on 20M & 17M?
?
Also the swr on the diagnostic screen is higher than what my SWR/Power meter says. Like I mentioned before, my dummy load measures 49.7 OHMS.?
After the QMX gets warm, I can no longer power it down unless I unplug it. Do I also have a power supply problem?
?
Sorry for being such a pain.
James
KA9TII
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QMX+ build: so close, and yet....
First, the good news: IT'S ALIVE.
It accepts power, it does not catch fire, and all the controls work and pass diagnostics.
The bad news: it does not pass transmit diagnostics, and all the different sweeps are wrong.
Attached is a (mercifully short) recording of the diagnostics screen including transmission into a dummy load.?
The most obvious problem is: wattage is 0!?
I'm using a buck-boost that's got the voltage at 12 (this is a 12-volt build). Idle draw is 0.115A. Draw when attempting to transmit during the diagnostic is 0.255, which seems low.
Obviously, some kind of rework will be necessary. What's my most likely culprit to start with?
Thank you all!
Michael WD0OM
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Re: Still no output on QMX
Hi Ludwig, I have some output numbers for you.
?
60M-<.5W
40M-<.5W
30M-<.2W
20M-9.9W
17M-8.4W
15M-5.5W
?
Do you have an idea why there's very little output om 60M-30M and too much on 20M & 17M?
?
Also the swr on the diagnostic screen is higher than what my SWR/Power meter says. Like I mentioned before, my dummy load measures 49.7 OHMS.?
After the QMX gets warm, I can no longer power it down unless I unplug it. Do I also have a power supply problem?
?
Sorry for being such a pain.
James
KA9TII
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Re: Still no output on QMX
did you have a good dummy load attached when you pressed T to turn on transmit?? The SWR of 2.8 is much higher than it should be.? With a 50ohm dummy load it should be 1.1 or so.
UpDate---Display is now working.?
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Re: Still no output on QMX
UpDate---Display is now working.?
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Re: Pwr output dramaticly decrease with higher Freq. from 6 W to 0W, for 160 to 20Mc
Hi Guido
I can only offer my findings for the same power output problem.? I found the driver IC in my QMX+, the 74ACT08D did not have sufficient output at the higher frequencies.? I found this with the oscilloscope but had to remove the BS170's in case they were loading the driver at the higher frequencies.? It proved that the voltage out of the driver decreased with increasing frequency.? I replaced the driver and the QMX+ operated correctly.
I hope this helps.
Regards
Greg
ZL4GW
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Re: QMX crashes on RF filter sweep (and other anomalies)
Hi John
I've got a little further with the fault finding.? Reverting to the earlier firmware made no difference.
With the good QMX+ I enabled IQ mode and ran Audacity.? After working out how to set it up I got the correct wave forms.? However on connecting the newer QMX+ I have a very different waveform which leads me to believing that the PCM1804 is faulty!!? It is sheer bad luck that both my QMX+'s had the same faulty IC. I should have ordered 2 of them from Digikey originally.
I can confirm that what you described with your hardware tests are exactly the same as mine.?
The transmitter works properly and there is output on all bands. The cw sidetone works.
So now I need to replace IC407.
I hope you have better success with yours.
Regards
Greg
ZL4GW
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James
Dirk