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Re: To socket or not to socket, that is the question!
I got brave and ran the Calibration routine on one of my QMX+ rigs. Sure enough, afterwards my RF output was about half of what it was before. It was a simple matter of clipping out the four BS170s, clipping the leads on four new ones to just a few mm, and "dead bug" soldering them over the place where the original four resided. No need to try removing the old leads going through that board; no need for sockets. This approach works fine for the BS170s and most other components on the board that need replacing. Plus, it's a lot easier on the board itself than heating it up enough to pull old leads.
--
Jim / K7TXA Eagle, ID SKCC 10447T BUG 301 |
Re: Failed software upgrade-help!
I see in your later post on another thread that you found the solution.?
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For others who may see this:
If your qmx fails to respond after copying the firmware into the QMX folder, just wait a few seconds,? then unplug the power cord from QMX, plug it back in, press the power-on button, and it will wake up with the new firmware.?
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This is a known issue, which happens on some qmx/qmx+ builds sometimes for unknown reasons.? It is not new to the ssb firmware.
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Also, do not delete any content from the qmx folder prior to updating. |
Failed software upgrade-help!
Well I have done it again.
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My QMX mounted. I deleted the old firmware and copied the new SSB version.
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I did notice there was another file that started with e.
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I emptied the trash and checked the contents of the mounted QMX volume. It was empty. I started to recopy the firmware and the QMX unmounted.
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It will not mount, nor will the unit turn on.
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What have I done and how can I fix it?
Jim |
Mini Microphones for QMX SSB
Hi everyone. With the release of the SSB firmware out of beta, I thought I would make my offer to source K6ARKs wonderful little microphones, which can be found here: , one more time.
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Adam (K6ARK) made a super fantastic little miniature mic case, and they work with the QMX quite nicely.
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I print the cases in PLA, and have the following colors available: ?
Black, White, Grey, Navy Blue, Orange, Light Green, Red, Gold, Purple, Sand Stone, Light Blue Stone, Turquoise stone, and Marble Stone (The stone colors look like marble or granite - little flecks of darker color in them - The marble one winds up looking like bleached bone).?
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The kit includes:
3D Printed case in PLA
3.5mm jack
Electret Mic Element
Microswitch for PTT
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For each mic, $10 for kit, $15 fully assembled and tested. This price includes shipping in the US. I am happy to make you more than one, some people want one for home and one for the go bag, that's great.
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You will need to provide your own AUX cable (3.5mm male to male) to go between the mic and the radio. I have had several ask what cord I am using, So I have included this link to one I am using and that I test all my assembled mics with; it seems to work quite well: https://a.co/d/36GDDXf (This is a shortened, non-affiliated link to Amazon.com page for the cable I use)
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If you are interested, send me a private email, and I will send you payment details. My email address is good on QRZ.
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Hi Hans,
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Yes, I see all those options.
But I remember you saying that all the graphs are now available on the LCD.
And that led me to believe that the SWR sweep would also be available.
On page 70, the name of the function is different from the menu ("SWR measurement" vs "Tune SWR") which further confused me.
Also, in section 8.6 on page 3 all the tests are broken out whereas in section 5.19 on page 2 the tests are not broken out.
So a quick search of the table of contents for the available tests led me to believe that SWR sweep must be available from the front panel (due to my assumption that the list of tests in 5.19 were the same as the list of tests in 8.6).
Now I know.? : )
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73, Mike KK7ER
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My BS170s failed in my QMX+. ?There was no power output showing on my Power Meter, the QMX display contrast had changed, the QMX case was getting warm, and the battery voltage icon on my QMX display was flashing. My supply was 12v limited to 2 amps.
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Here are my steps to diagnose and repair my QMX+. I will add pictures, I hope groups.io will keep them.
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1) Power off and remove the supply and all connections. Remove the case top, bottom, and rear, and remove the washer and screw holding the BS170s to the PC board.
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2) Connect a dummy load and power supply.
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3) Power up and quickly check the temperature of Q503, Q504, Q505, and Q506 with your finger and if you have one, a digital infrared thermometer gun. I checked the temperature with my finger first, and two of the BS170s were too hot to touch and two were room temperature. The two hot BS170s measured 94F and the other two measured 78F.
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I powered my QMX down after about 20 seconds, because I did not want it getting too hot. After a cool down period, I powered it back up to make other measurements. The temperatures of Q507 and IC503 ?were close to ambient. I measured the voltages on Q503, Q505, Q507, Q513, and Q515 to be as follows:
Q503 and Q505
Source 2.35v
Gate 0v
Drain 0v
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Q507
Source 2.44v
Gate3.3v
Drain 5.9v
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Q513
Base 0.4v
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Q515
Base 3.25v
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4) Because of its high temperature and obvious high current draw and after powereing off and disconnecting the power supply I cut just the Source lead of Q503 and Q505. I powered up and measured the voltages on Q507. No devices got hot.
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Q507
Drain 11.3v
Source 11.3v
Gate 6.7v
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5) I powered back down and remove the PS. I then cut all the leads on Q503 and Q505 to remove those Mosfets. I cleaned the board with Q-tips and denatured alchohol. To remove the leads from the circuit board I held the lead on the front side with needle nose pliers and heated the back side with my 140W weller gun. When it became loose, I pulled the lead out thru the front. While heating from the back side I sucked the solder out of 4 of the 6 holes with a solder sucker. The remaining two holes were connected to the ground plane and I didn¡¯t try to clean them out. ?
6) While heating the one hole not cleaned out from the back side, I started a new BS170 into Q503 and Q505. I continued heating while lowering it down to a proper height. I then folded it over, checked the fit, and soldered all three leads of each Mosfet. I affixed all 4 Mosfets to the PC board with the screw, washer, and nut.
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7) I soldered and trimmed the leads on the backside, and inspected them. After connecting back the PS and dummy load and powering on, Q503, Q505 and Q507 measured as follows.
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Q503 and Q505
Drain 0v
Source 11.3v
Gate 0v
Q507 Drain 11.3v
Source 11.3v
Gate 6.7v
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I measured the power output to be 3 watts on 20m. I also ran the PA test which was as expected.
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8) I reinstalled the QMX in its case, connected the dummy load and PS, and ran the SSB calibration, which completed successfully.
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Hope this helps!
NQ5P
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? |
Hi Mike It's called "Tune SWR" and it still has the same functionality as in 1_01_027 - which is not a graphic SWR sweep. On my hardware tests menu on 1_02_000, I just checked, i see: AF filter sweep RF filter sweep Image sweep Tune SWR LPF sweep PA mod. test Test ADC I/Q SSB Calibration Microphone test Diagnostics GPS Viewer Do you not see all these?? 73 Hans G0UPL On Tue, May 6, 2025 at 6:01?PM Mike KK7ER via <groupio=[email protected]> wrote:
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Re: Why I think QMX Calibration Kills PA
Hello all Many people, myself included, have run the QMX calibration procedure multiple times without damage to their BS170 transistors. I was developing the QMX firmware for 9 months, including?the calibration procedure which I ran literally hundreds of times while developing it. Some unexplained failures have indeed been reported too. During the last 9 months I lost one set of BS170s due to a coding mistake where the '5351 output got parked low, not oscillating, at the same time?as the TX enable signal to the logic gate driver was high. I lost another set of BS170s (and the Tx/Rx switch) when I was away on family vacation during a large?storm, which also destroyed?our office internet router and one of the network ports of my PC. Other than that, my BS170s run without any damage or degradation. My QMX+ is still a Rev 1 QMX+, with the plug-in SMPS modules. I did fry one SMPS module once during these 9 months due to sloppy work, a 'scope probe slipped and shorted something. A component being observed to run with some datasheet spec violation is NOT proof that the violation is causing or contributing to failure! If an unknown failure occurs at an unknown (low) probability, it is also not proof to attribute it to an observable violation.? However, that said, I agree that if there is no envelope shaping on the calibration transmissions, this is an unnecessary situation. It is not necessary to take such risks. It is always better, all things being equal, to respect datasheet specifications. There is no reason why I should not be able to shape the RF envelope nicely as occurs during CW keying. So let us not panic. But I will investigate this with high priority and apply envelope shaping as soon as possible. If I can, I will do it before I leave for US on Monday (for FDIM/Hamvention) but time is very tight now.?? 73 Hans G0UPL On Tue, May 6, 2025 at 4:53?PM mux_folder2001 via <canthony15=[email protected]> wrote:
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Re: Feature Request List?
* I would love to have a waterfall, while working SSB. That would require a second soundcard, I guess
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* I do second the NMEA-Output. That would reduce the number of antennas in my configuration.
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* It would be great to have some kind of API. BASIC has been in discussion, surely easier said than done. We have CAT - that already does cover a good part of that feature? |
FYI: Yesterday I updated a QMX rev1 (first release unit) from 1_00_017 to 1_02_000.? It was a "textbook" process--used terminal for all control, so put into flash drive mode; copied image; powered down, and started up just fine.? Did a factory reset, and then did the full calibration, using a BarbAWatt meter with its 10W dummy load.? Quit a lengthy process!? Fun to watch the power meter :)? ?Anyhow, it seems just fine.? No SSB testing yet--building a mic is on the agenda next.??
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Great work, Hans!!?
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73,
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Mark N8MH? |
CW Practice / Rag Chew
¿ªÔÆÌåÓýOn May 06 I had a CW practice / rag chew session on
20 and 30 meters. I worked three stations:
Conditions were not great with lots of QSB. SSN =
108, SFI = 159, A = 29, K = 3. I was using my Elecraft K3 at
100 watts with my 100 foot sloped doublet. I started out on
20 meters but switched to 30 hoping for better conditions.
They were a little better but not much.
My next CW practice session will be May 07 at 18:00 EDT / 22:00 UTC on 30 meters. Anyone and everyone is welcome. This practice is intended for operators who are new to CW or they need some practice. IT DOES NOT MATTER HOW POOR YOUR CW IS. Mistakes are OK. Poor fists are OK. Slow speed is OK. Really slow speed is OK. This practice is meant for you to improve your CW. I will do my best to adjust to your skill level. Operate at any power level. If several stations show up, I will operate as a round-table control station. I will do it as a round-table so everyone gets a chance to transmit. Please listen to my directions. Details: Date - May 07 2025
Time - 18:00 EDT / 22:00 UTC Band - 30 meters How to find me - I will find a clear frequency and call CQ. Go to the Reverse Beacon Network and search for my call sign AB8DF. That will tell you what frequency I am on. Tune
your station to that frequency and if you hear me give
me a call. If there is a QSO in progress, please wait
for a break in the action. Then send your callsign. If I
hear you, I will invite you to join the QSO and start a
round-table QSO.
Reply to this email if you have questions. IT DOES NOT MATTER HOW POOR CW IS Ed AB8DF |
Re: Why I think QMX Calibration Kills PA
¿ªÔÆÌåÓý
Hi Chuck,
I did measurements with the standard scope ground but also with ? inch leads soldered to the transistor and attached to the probe. The probe ground causes some high speed ringing but the fat part of the pulse is basically the same.
If it offers any reassurance, I spent my career in the high speed logic business. Many hours looking at nanosecond edges and I am very familiar with the effects that are produced by the scope probe ground leads. I am convinced that the bulk of the large pulse
is real. As to its cause, it is only speculative. I did some measurements in QDX that convinced me that the issue there was due to the inductor. But I have not repeated those experiments with QMX. So, there could be more here than meets the eye, or not.
73,
Tony
AD0VC
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From: [email protected] <[email protected]> on behalf of Chuck Harris via groups.io <cfharris@...>
Sent: Tuesday, May 6, 2025 6:54 AM To: [email protected] <[email protected]> Subject: Re: [QRPLabs] Why I think QMX Calibration Kills PA ?
Out of curiosity, how are you connecting the probe's ground?
Even at a low frequency like 1.8MHz, more than 1 inch of probe grounding wire will make a signal ring like that. -Chuck Harris, WA3UQV On Mon, 05 May 2025 11:40:18 -0700 "mux_folder2001 via groups.io" <canthony15@...> wrote: > I just hooked my scope up to the drain of one of the? PA transistors > in my QMX+ and kicked off a 160M Phase cal (O button). I am seeing > 120 volt spikes during the cal. > > Here is a link to a screen shot from my scope: > > 160PhaseCalGlitch.jpg ( > > ) > > This is going to fry some BS170s? for sure. > > Tony > ADoVC > > > > > |
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