Re: QDX v3 - T203 Xfrmr PCB holes too Small for 0.6mm Wire
Hi Jerry
I have a rev 3 and did not have that problem. Did you tin the
ends first---I seem to recall that this is mentioned in the
assembly manual, to tin them after they have been pushed through.
If so, maybe try wiping the wire when the solder is melted, see
if you can get the diameter down a bit.
73
Roger
8P6RX
On 26/07/2023 16:37, jsternmd wrote:
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I checked the PCB T203 thru-holes with a 0.6mm PCB drill bit and
it was tight but passable.? I only had a 0.7mm PBC bit (does
anyone make a 0.65 PCB bit?) and using a pin vise I slowly started
to enlarge but quickly stopped as I saw the pad was beginning to
lift up.? I guess a high speed drill could do the job with less
risk to damaging the pad but now it seems I will have to rewind
the toroid with 0.50 mm enameled and hope for the best.??
jerry
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Re: QDX v3 - T203 Xfrmr PCB holes too Small for 0.6mm Wire
I checked the PCB T203 thru-holes with a 0.6mm PCB drill bit and it was tight but passable.? I only had a 0.7mm PBC bit (does anyone make a 0.65 PCB bit?) and using a pin vise I slowly started to enlarge but quickly stopped as I saw the pad was beginning to lift up.? I guess a high speed drill could do the job with less risk to damaging the pad but now it seems I will have to rewind the toroid with 0.50 mm enameled and hope for the best.??
jerry
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QDX v3 - T203 Xfrmr PCB holes too Small for 0.6mm Wire
I bought my v3 top band QDX in 2022 but just got around to assembly this week.? I wound T203 with supplied 0.6mm enameled wire only to find it's too large for the T203 PCB holes? - even with the enamel completely removed.? The wire measures 0.64-0.65 in my digital micrometer.? I could take a PCB drill bit and enlarge the holes but then it may lose continuity between top and bottom traces if I destroy the hole solder fill with a drill bit.? I can get some 0.5mm enameled but I assume it will change the desired transformer characteristics.
Any advice appreciated.
Jerry
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FREE template for paper logbook pages
Visit the AF4K Crystals website for access to a FREE template for paper logbook pages. ?
http://af4k-crystals.com/ ?
Thanks...
73?? Steve? WD8DAS
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Re: QMX USB socket not soldered?
#qmx
I just completed mine, but I did have to re-solder the USB connector.
I loaded the firmware, and it booted up as a radio. (Hurrah!)
As I was running the hardware tests from Putty, however, the connection dropped and Windows pinged to tell me that the device wasn't recognised.
Applying gentle pressure to the USB connector made it come and go...
I went over all the USB solder connections with a hot fine tip iron and added a little solder to each.
Now it works fine.
All the filter plots look good, and I'm getting between 4 and 5 watts out on all bands with 12V supply.
73
Adrian
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Re: QMX: Processor not booting / row of bricks
Hi Simon,
Looks great. I'm puzzled though, I still have the C403 installed and my sweeps look much like yours. The shape is only slightly different. Your initial sweeps looked like what you get without a dummy load attached. I'm just trying to confirm that it was really the C403 that fixed things, before I consider removing it from mine. Below are my sweeps.
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...And the solution is: I still had capacitor C403 in the circuit (might be an idea to add that to the sensitivity mod). After removing C403, the sweeps look great:
<20m take2.png><40m take2.png>
(The only mystery now remains the power board...)
73!
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Re: QCX Birthday - 20,000 sales coming up!
I assume that "James Harmuth, USA", will receive a kit with appropriate gold commemorative markings on the case to confirm the milestone? ?
Brock VA7AV?
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QDX at QRPpp this morning
Tnx QSO, AA5AT.
72,
Bill, N4QA
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Re: Here's what QSOs look like from the W4MAI ( SK 2006 ) Memorial Sun room monitoring station.
I just love it when the entire QSO is displayed on the combination Malachite Malahit having a ~ 14-inch whip and Dell i3 PC !
72,
Bill, N4QA
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Main microprocessor failure
#qmx
Hans,
Where can I find a replacement microcontroller for the QMX? Mine has a dead short internally.
S/N 331 has been functioning nominally now without issues (except for those noted BPF and CW issues). I usually operate it from fused 8 volts and always good impedance match so no strains. Was working properly when I shut it down in the afternoon. Following morning I placed it on the test bench prior to testing CW keying. Applied 8 volts from the bench supply, current limited to 800 ma. When I pressed the left encoder switch to power it on the current jumped to 600 ma. for about half a second and then dropped. Nothing else happened.
Disassembly and test revealed VDD shorted to ground with less than 3 ohms. Using a Siglent SDM3045x DMM (which has 2W resistance resolution to .01 ohm) I carefully traced the low resistance to the microprocessor VDD inputs. It was quite tedious without Gerber files to be able to trace those "underground" tracks.
Under the microscope I carefully unsoldered each VDD pin, raising it above the pad, until I raised pin 19 (VDD2) which cleared the VDD bus. All of the VDD pins except for VDDA seem to be shorted to ground.
I am unable to determine a cause. Everything is in place and solid (I am a very careful builder. Slow but careful) and nothing has been intermittent. I wouldn't think that it could have been over-voltaged since D109 is in place (but I have not removed it for test). Nothing was attached at the time of failure except the power and a dummy load. Power was supplied by a Siglent SPD3303x-e which I have found to be very reliable. The DMM is very gentle, and applies only 0.65 volts to the probes and I have never experienced a problem caused by it.
I am not sure of the nomenclature of the chip since it is covered by a waxy coating. Your FDIM presentation mentioned a STM32F446VET6. Could this be it? Is it ordered with any special programming?
I may delay further work until a year has passed. It has been a time consuming project up until now and I should probably wait until the dust settles before devoting much more effort. Other projects are calling.
73, Don
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QDX Terminal Emulator - problem editing values
In terminal emulator mode on a serial port, I am unable to edit certain numeric fields using delete or backspace. Specifically audio gain value under band configuration menu that is default to 54.
QDX HB Rev 5 with v1_10 firmware. Running MobaXterm on Windows 10 PRO.?
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Re: QCX Birthday - 20,000 sales coming up!
Hans,
20,000 !! QCX series ordered (to date). Outstanding piece of work to you and your crew.?
73 Kees K5BCQ
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Re: QMX unboxing and a couple of surprises
Mine arrived today - box was damaged a bit by customs/courier. All content in tact. Boards solid in one piece and no missing/broken elements (at least didn't found them at initial inspection).
BTW it was record delivery time :
- Collection 4 days (including Sunday)
- Grezimir to Dublin 19h (yes 19hours !!!- still cant believe as last time was about a week)
- Customs/local TNT depot? 1.5 day
Thank you Hans - looks they finally taking it seriously (at least outside of Ireland :D )
73 de Robert EI9ILB
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Re: QMX unboxing and a couple of surprises
2nd QMX arrived Monday. My PCBs were split too. Package did not look as if it was damaged. Have not checked out the rest of the contents.?
--
73, Dan? NM3A
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Re: 50W amplifier - 13.8V power supply
I have one of these $20.00 Amazon converters and it has wandering noise spikes that blot out strong shortwave signals as the spikes wander by slowly, usually down freq. Now, was gifted a switching supply from MFJ that is electrically silent but has noisy cooling fans!
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Re: 50W amplifier - 13.8V power supply
John,
How does the ripple look during large current draw when the TX is key'd up?
Unfortunately, I do not have a working o'scope, so I can't speak for what the output looks like during use :-( Regards, Charles Johnson KF4AYT
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Re: QMX C218 Replacment Part from Digikey?
I just did a quick search on Amazon and found these ...
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Re: QMX unboxing and a couple of surprises
Hans,
Thanks for your prompt reply. I¡¯d already ordered some 47nF capacitors so I¡¯ll probably fit them, but it¡¯s nice to know that they aren¡¯t critical.
73
John
G4YTJ
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Re: QMX unboxing and a couple of surprises
Hello John
The first thing I did was to check off all components against the parts list. There were two knobs in a separate bag and another two in the main packaging, so I¡¯m two knobs up! The knobs all appear to be the same size.
Bonus for you! Kick for my colleagues...??
I then removed the PCBs from their anti static bag and immediately photographed them. The LCD board was broken off from the main board - I¡¯m not sure if that¡¯s to fit them in the bag or whether it got damaged in transit.
That's not how we pack them, we pack them in one piece. Not broken apart. So this must be a transit thing. Nevertheless it's the first time I have heard of this so I think it's not common, and in any case the first thing you are going to do is break the boards apart so it should not matter.??
Looking at the photos I saw that C205 and C210 had broken off the main board. Coincidentally one of them appeared in one of the other photos, and I found them both on the tray.
C210 is a 100nF decoupling capacitor and might not be critical, but C205 (47nF) is on the processor reset line and might be essential.
Neither of these capacitors are critical. I believe the 47nF on the reset line is only required during Flash programming of the bootloader. Once done, it is not a requirement. The other decoupling capacitor as you say, is a prudence (follow all datasheet recommendations on capacitors everywhere) but it should still work without it.?? I¡¯m quite happy to resolder the capacitors but neither of them check out with their correct value (my DVM has a capacitance range, I checked some through hole capacitors to confirm that it was working).
I wouldn't worry about that either. I don't use expensive precision capacitors for the capacitor positions where it is not critical. The expensive capacitors go in the LPFs and BPFs.?? My suspicion is that the capacitors got knocked off by the LCD board in transit, which is why they were in the packaging.
I suspect you are right? Hans, if the boards are supposed to be separated, can I suggest something like a piece of card slipped between the two to prevent the capacitors from being knocked off?
The PCBs aren't supposed to be in two parts...? If I order some replacement capacitors, I¡¯m thinking of substituting 47nF for C210 so I¡¯ve only got to order a couple of the same value.
I would just use the supplied ones. Or not bother...?? Any comments/suggestions gratefully received.
?I'm sorry to hear about the mishaps but I think these are non-critical things, that won't affect anything about the build outcome - so I'd just proceed regardless...
73 Hans G0UPL
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Re: QCX Birthday - 20,000 sales coming up!
Here is a 2017 tooling up for the 2023 es 2024 solar eclips
Check out my QRZ page
...Copied from bowels of this old tablet ...
...(2017dec31 ... QCX 80, 40, 20 ... sn 1166, 7, 8 ...arrived 2017nov25)
HAPPY BIRTHDAY es many MANY more
72 73
John
N3AAZ
FM19 on DELMARVA Peninsula
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Adrian G4AZS
Don, ND6T
Scott Tillotson
EI9ILB
Karl