Re: Another QDX went up in smoke
What can you tell us about your antenna SWR?? We assume you weren't connected to a dummy load since you were receiving and then transmitting.
Your small power adapter had very low current sourcing rating, so it was probably sagging voltage considerably.? If true, that means you were remaining lucky -- only because of your limited power input.
PA3CRZ >> I did not raise the voltage.
With the more robust power adapter you presumably reached at-or-near full voltage, and maybe overvoltage ... and then not so lucky.
Hopefully the only smoked parts were the final amplifier transistors.? Those are a relatively easy fix.
Don't damage your board trying to get parts out.? Start here with "Mr SolderFix":
This guy has very helpful videos on board repair.? Very reassuring, "you can do this" tutorials.? Worth your time to watch even if you don't learn anything new.
If you need to replace your final amplifier transistors, change them all.?They're cheap.? Cut those BS170s out with your diagonal cutters first.? Then you can remove the lead remnants one at a time, flux, soldering iron, tweezers.? If you have to remove any other multi-pin parts, like ICs, use desoldering alloy or a heat gun or the techniques in Mr SolderFix's video above.? Personally I favor desoldering alloy.? If an IC has a heat sink pad underneath, soldered to the board, the only way to remove it is with a heat gun.? But I don't think QDX has any parts like that.
Beware overvoltage on those plug-in power adapters.? You cannot trust them!? If you don't have a voltage-regulated, current-limiting power supply to do your initial testing with, buy a buck converter or a buck/boost converter and set it to a lower voltage than your rig's specified max input voltage.? It is very much worth it to treat your new radio gently.? 5 to 6 volts is a good place to start on a 9 volt max input transceiver.
Turn your power supply on first so it stabilizes, then connect your radio to turn it on.? Three people above have already mentioned that.? A lot of radios have been toasted by turning the power supply on with the radio already connected.? This is not a problem if you're running on batteries (with voltage less than the rig's max input voltage), but it can be a problem with many electronic power supplies.
Don't try for maximum output power.? Be happy with a watt or two less.? Lower the input voltage.
Don't use an automatic antenna tuner/matcher.? You will fry your finals, sooner or later.? I promise.
Good luck with your new rig!
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Re: Another QDX went up in smoke
I always first plugs my power supply in the AC socket then after one minute plugs it in my QDX, expecting that any power on spikes are a matter of the past.
73?
Pierre?
FK8IH
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Re: QDX won't load firmware...?
Page 6 of the operating manual:
I *think* it's supposed to start with the first block and then
proceed to one of the latter blocks. That it doesn't start with
the quick flash sounds like a problem. Trying to find signs of
life: Can you tell if one of the receive bandpass filters is
selected. If they're all off, it sounds like something has crashed
(which I think you suspect!)
Does it make any difference if the USB is/is not connected at
power-on? If not connected at power on (assuming no flashing), if
you plug into the windows machine, are the correct devices
created? (Implies the MPU isn't totally berserk...) Are clocks
being generated, are they at the correct frequencies?
Again, grasping at straws to see where things go astray. Wonder
if there's some way to use DFU to read what's been programmed, and
compare that to what it's supposed to be. :-(
Paul
On 7/22/23 09:19, Leigh KG7WED wrote:
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On Fri, Jul 21, 2023 at 04:30 PM, Paul - AI7JR wrote:
Rereading this thread, I too wonder what's going on:
- I suspect that until you successfully load the QDX image,
the terminal won't be available (e.g., it's part of the QDX
image.)
- If the (audio & com) devices are coming up, something
must be working...
What happens if you try to talk to it with, say, flrig? Is
there a way you can prove it's actually dead or alive? Would
fldig or wsjt-x tell you if the audio stream was dead or
alive? (Does the CAT test and PTT test work or not?)
Thank you. To your first point, I now think it is loading
firmware OK. It goes into bootloader mode, appears on the
desktop as a flash drive, and I can drag and drop the QDX image
into it. Then it appears to be happy with what it received,
because it reboots itself once it finishes reading in the
firmware.
About talking to it with other apps besides the terminal mode, I
posted a screenshot above from JS8Call, showing the hamlib error
that it throws. WSJT-X shows a similar error, since they both
use hamlib for rig control. I don't have flrig set up on this
system, so I haven't tried that.
Again, the serial connection was working before, for
the first few days I ran the QDX. And then, without me changing
anything on the computer side, it stopped working.
The main hardware clue I'm chasing down at this point is that,
in "normal" mode, the front panel LED just lights up steady the
whole time. It is not doing the "Quick flashing
(flickering) for first 5 seconds after power up" that
it's supposed to (again, it?was doing that flashing
before).
I have asked Hans in my support ticket what this non-flashing
LED behavior might indicate, but I haven't gotten a response.
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Re: #qdx firmware 1_10 release
#qdx
Hans,
Did you solve the "Japanese bands" bug found in Hi-Bands QDX?
73?
Pierre?
FK8IH
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QMX CW Stutter noted : Firmware Version 1_00_005
Alas....the CW stuttering is "back"... With the Battery indicator turned on, and worse when both the Battery and S-Meter indicators turned on.
(CW decoder is enabled for both xmit. and rcv., if that helps troubleshoot this.)
es vy 73 de "baab" w9ya
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Re: #qmx low power output
#qmx
Some thoughts:
(Hopefully you are not measuring these high frequencies with a DVM,? It can be done Using a diode to rectify the AC)
Since the input current appears about right I would look for an open between T501 and the antenna.
Since there is low power on all bands I don't think it is likely the band pass inductors but I would still check with an ohm meter.
Double check the winding going through the SWR transformer T507? C to C (maybe B to B)
If the PIN diodes D8-D13 were in backward it could probably case the issue.?
I would tack a wire onto the output side of T501 and see if? it has significant HF signal.??
I haven't built mine yet, it has just been shipped, but I have built QDXs and QCXs?
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Re: Another QDX went up in smoke
That¡¯d do it.? I have a good, regulated supply, but when set to 5 VDC (for my U3) the voltage will spike on turn-on.? Took me a while to figure out why I was toasting microprocessors.? ? Mike WM4B ?
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From: [email protected] < [email protected]> On Behalf Of KK4ITX John via groups.io Sent: Saturday, July 22, 2023 5:43 PM To: [email protected]Subject: Re: [QRPLabs] Another QDX went up in smoke ? I MHO, unless you have a genuine regulated power supply, ALL QRP rigs should be run from battery power only and even then the voltage should be very close to the specs of the rig without using buck converters unless a dedicated one. Possibly your PS initially puts out excessive voltage? KK4ITX? ?Each mistake is a learning opportunity.?
On Jul 22, 2023, at 12:25 PM, Paul Christensen <w9ac@...> wrote:
? Hans, ? Is the +9V/1A supply regulated?? How much voltage do you measure from it? ? Paul, W9AC ? ? Yesterday, I ran my QDX for the first time off a 9V / 160 mA power adapter. You know, one of those things similar for charging your phone.
It was receiving properly, and I was even able to make some QSO's.
Today, I decided to use the same kind of power adapter, but this time a 9V / 1A version.
The QDX started out normally by flashing the led rapidly, then the led went off and smoke came from the QDX.
What in Earth may have happened here ?
I did not raise the voltage. The only thing that was new was that the adapter can supply more amps.
Any help would be appreciated.
Tnx,
73 Hans
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Re: Here's what QSOs look like from the W4MAI ( SK 2006 ) Memorial Sun room monitoring station.
Hi ya Willie ! eQSL Archives *AND* Outbox !
As you may see, some of my QSO partners have seen their eQSLs and responded in kind.
No question at all about output power. OHR WM-2? ? "TELL NO LIE!"
Only band where power out is in doubt is Top Band...original QDXs like mine..."NO DESIGNED" for 160m.
Comprender ?
72,
Bill, N4QA
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Re: Here's what QSOs look like from the W4MAI ( SK 2006 ) Memorial Sun room monitoring station.
There¡¯s some question about the <ahem> accuracy of those power readings, but that¡¯s a whole ¡®nother thread (which can be found in the archives).
73, Willie N1JBJ
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On Jul 22, 2023, at 5:29 PM, KK4ITX John via groups.io <jleahy00@...> wrote:
Since he¡¯s running a limping QDX on flea power
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Re: Another QDX went up in smoke
I MHO, unless you have a genuine regulated power supply, ALL QRP rigs should be run from battery power only and even then the voltage should be very close to the specs of the rig without using buck converters unless a dedicated one.
Possibly your PS initially puts out excessive voltage?
John? KK4ITX? ?Each mistake is a learning opportunity.?
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On Jul 22, 2023, at 12:25 PM, Paul Christensen <w9ac@...> wrote:
? Hans, ? Is the +9V/1A supply regulated?? How much voltage do you measure from it? ? Paul, W9AC ? ? Yesterday, I ran my QDX for the first time off a 9V / 160 mA power adapter. You know, one of those things similar for charging your phone.
It was receiving properly, and I was even able to make some QSO's.
Today, I decided to use the same kind of power adapter, but this time a 9V / 1A version.
The QDX started out normally by flashing the led rapidly, then the led went off and smoke came from the QDX.
What in Earth may have happened here ?
I did not raise the voltage. The only thing that was new was that the adapter can supply more amps.
Any help would be appreciated.
Tnx,
73 Hans
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Re: Here's what QSOs look like from the W4MAI ( SK 2006 ) Memorial Sun room monitoring station.
I could live with that if he'd just keep it on the same thread so he could be muted.
Mike WM4B?
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Re: Here's what QSOs look like from the W4MAI ( SK 2006 ) Memorial Sun room monitoring station.
What actually might be worth the effort is to document the QSOs on a map with mileage rings and colored dots indicating the power used.
Since he¡¯s running a limping QDX on flea power it¡¯s probably of interest to various ops? ?At least it shows that using flea power is both fun and practical.
I could do without the extra bandwidth though, but there is a story to be told.
John KK4ITX?
?Each mistake is a learning opportunity.?
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On Jul 22, 2023, at 1:48 PM, Mike Besemer - WM4B <mwbesemer@...> wrote:
? True unfortunately.? ?If one must toot one's own horn, so be it, but I'd rather not be forced to listen to his music.
Mike WM4B?
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Re: #qdx firmware 1_10 release
#qdx
On 22/07/2023 19:02, Hans Summers wrote: any clarification to the operating instructions if there is any part where Windows-specific information is needed. Hans, There is not much difference. Having tried WSJT-X on a Raspberry Pi I reckon selecting the correct audio was more difficult than Windows, one setup showed the QDX, another did not.There were lots of choices, none obvious but try them until the signal bar comes alive. Some have looked for the dev/tty in Windows instead of a COM port but that's about all. Most other problems are unfamiliarity with the OS, and that counts for both systems. 73 Alan G4ZFQ
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Re: QMX C218 Replacment Part from Digikey?
Clansd
I cannot readily tell if you damaged the physical capacitor or its surface only.?
I have one than one device with a surface mount capacitor replaced with a leaded one, just clip the leads very short. The designer does mention it's uncertain whether you will notice this part missing, if it really is damaged.?
I confess to collecting lots of parts, but few are surface mount. I am curious of Gwen's wisdom on the identity of purchasing these sample kits, who sells such things?? Yes I know in the past some suppliers would give them to experimenting engineers generally in their plant or at a conference. But any wisdom to help experimenters across the globe find parts is worth sharing.?
Curt wb8yyy?
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Re: QMX C218 Replacment Part from Digikey?
Nothing like a little CDA-CALEO (Catastrophic DisAssembly - Component Attempting Low Earth Orbit) to lend excitement to ones day. I have had a MRF237 whiz by my ear like a comet; amazing what happens when you forget to heatsink your finals and go key down for too long (Heathkit HW-9, which I still own).
73 de Lee KX4TT
?
On Saturday, July 22, 2023 at 04:22:33 PM EDT, Gwen Patton <ardrhi@...> wrote:
Catastrophic disassembly is an infrequent but extant difficulty I've run into a few times. Once is happenstance, twice is coincidence, three times is enemy action...so I keep spares of any part I purchase.
-=-=-=-=-=-=-=-=- 73, Gwen, NG3P _.
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Re: QMX C218 Replacment Part from Digikey?
Whenever I need to do a replacement like this, I look for a sample book that contains that component, then buy the sample book. The reasons were pretty straightforward in my thinking -- I get multiples of the affected part, sometimes up to 50x of them in a short piece of component reel tape. That part is usually accompanied by other components of the same type, in various values, again, in significant quantities?for a hobbyist's needs. And the price is usually manageable, considering I'd probably pay the same amount on a sample book of a specific size and range of SMD capacitors from Amazon on Prime as I would buying one component from Digikey or Mouser when you consider the inflated price of qty 1 AND the inordinate?shipping costs for such a small order. I really wish those providers would just pop a couple of SMD caps in an envelope, even a padded one, and drop it in the mail. That'd be cheaper than the insanely inflated shipping charge they assess, no matter how small the order.
Over time, I've got about a third of a drawer in my rolling toolchest?full of sample books. I also have small bags of components that were part of a shipment from Digikey or Mouser, as I tend to buy 10-20x of a part if they're available. The price is sometimes less per part that way, and I have spares on deck in case I flub something or something untoward causes the component to fail. Catastrophic disassembly is an infrequent but extant difficulty I've run into a few times. Once is happenstance, twice is coincidence, three times is enemy action...so I keep spares of any part I purchase.
But the sample book solution is one I didn't know about at first. It was only later that I learned the things existed, and they can be found for very reasonable prices. Amazon and Ebay have been decent sources in the past.
-=-=-=-=-=-=-=-=- 73, Gwen, NG3P
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Re: #qmx low power output
#qmx
Three dioptre reading glasses on top of whatever you already use
can help.
Don't expect anything more that 18 inches away to be in focus.
Chris, G5CTH
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Re: #qdx firmware 1_10 release
#qdx
What I've found with Windows is that as long as you don't change
the position a USB port is connected - the USB port, including
hubs, active extensions, then it's ID doesn't change.? And if you
have a FTDI USB to serial interface once it's been pluggen in and
assigned a COM id that doesn't change.
It's also possible to give an audio port a name, so my IC-7300
USB ports can be identified.? Don't expect that to be portable.
But fundamentally, as long as you connect using the same
connections things don't change.
Chris, G5CTH
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Re: #qmx low power output
#qmx
1V RMS in 50 ohms is 20 milliwatts, so low indeed! Take a look at the RF Power measurement section of the QCX manual (section 5.5 in my manual). There are some hints there that may help. Since you are drawing full DC current during transmit, it suggests you have?an open circuit somewhere beyond the PA section, most likely in the low pass filter. Double check the toroid soldering and make sure all the enamel has been scraped / burned off and you have continuity.
GL, hope that helps.
Brian n1bs
On Sat, Jul 22, 2023 at 1:24?PM Mark Volstad - AI4BJ < mvolstad@...> wrote: Rx on my QMX appears to be working correctly, but I have low/no power output on Tx on all bands. On 20/30 output is approx 1 Vrms into a dummy load; on 40/60/80 it's barely 100 mV rms. On ALL bands, current draw is around 1.25 A during Tx. My QMX is wired for 12V, and that is what I am testing with. During Rx, current drops to roughly 150 mA.
?
I'm running the latest firmware (005) and have performed a factory reset. Troubleshooting suggestions? (I have a scope.)?
?
Mark? AI4BJ
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Re: Software for Hobby RF Design?
Re: the many crystals? ? ??
When the dinosaurs were young and I worked in VHF/UHF mobile radio, problems in the new-fangled diode switching of the TX/RX channel crystals would often result in confusion by the user being on more than one channel.? Worth remembering any time an oscillator generates a square wave it is a signal with many harmonic frequencies.? It doesn't care.? Nor does an audio amplifier reproducing a song.? ?
For closely related frequencies it is certainly possible for a single impulse to 'ring' several crystals?each at their own frequency ( Dare I mention tubular bells)? and the active circuit element will be pleased to amplify them all? , and then again the oscillator may just be dithering between the different frequencies and different crystal activity points if we could look closely enough.
So very possible but not immediately useful.
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Pierre - FK8IH
Paul - AI7JR
Mike Besemer - WM4B
KK4ITX John
Lee
Gwen Patton
Bruce Akhurst