Re: QMX+ build: so close, and yet....
I seldom use the approach of pulling on a thread. ?Hi hi. ?My approach is to fix what is obviously wrong. ?Then go to the next thing that is obviously wrong. ?In the end all gets fixed. ?And I try very hard to understand why something was wrong. ?
for example, here in this thread I saw a message that the bias current is 60ma. ?It should be 30ma +/- a little bit. ?I would tackle that first. ?An easy to diagnose circuit.
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after that if I still have 0 output, I would trace from the drivers, through the finals and through the lpf circuits to see where this big Tx signal disappears.
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--
73
Jeff Moore
W1NC
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Re: QMX mid band build - Continuity between A and B points
I'd be tempted to try two things.
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1) With T501 still removed, bend the wire ends down as if they were soldered into the PCB and make the continuity checks for the primary and secondaries again. Look closely at the ends near the binocular core edges to see if the insulation got cleared away a little too far up the legs and are possibly touching the core, or between the primaries and secondaries.?
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2) Rewind T501 being sure to follow the winding instructions exactly.?
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Greg
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Re: #QMX Loaded FW 27, Now Dead?
#qmx
On Thu, Sep 12, 2024 at 05:03 AM, Todd Howell wrote:
I'm getting some weird data:
Voltage: 13.2v (input is still 11.4v)
5V SMPS: Status: Error
? ? ? ? ? ? ? ? ? Voltage: 4.6v (I was measuring 5.84v)
?
It seems satisfied with the 3.3v SMPS, although it's saying 3.57v where I was measuring 3.28v.
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Hello Todd,
where did you measure VDD = 3.28 V? What is the status of the SMPS 3V3, "SMPS" or "analog" (or so) (see Diagnostics screen)?
Could you show please a screen shot from terminal - Diagnostics?
Please check VDD and VCC at the pin header of the SMPS (see here). Is the display backlight on (VCC is available to the mainboard).
?
73 Ludwig
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Re: QMX RF Filter Sweep (80m) Fails The First Time the Test Is Executed
Hi
This is a known firnware issue. I'm not yet sure what the cause is. The workaround for now is stepping up a band then down again.?
73 Hans G0UPL
Yes I have experienced exactly what your describing.?
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Re: QMX+ build: so close, and yet....
Michael,
Be careful pulling on threads¡. When I do that everything becomes unraveled. ?Have a great time exploring. The outcome will be fun and Jeff and others are standing by to help further. Be the REASON someone smiles today.
Dave K8WPE
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On Sep 26, 2024, at 8:50?AM, Michael - WD0OM <wd0om@...> wrote:
? Jeff,
I have no doubts at all about that last part. Anything not working here is on me and my relative noviceness! The kit is great and the instructions (mostly) very clear!
T501 And L502 make sense as starting points. Thank you. Just needed a thread to start pulling on.
Michael WD0OM
On Thu, Sep 26, 2024, at 05:45, Jeffrey W Moore via groups.io wrote:
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
?
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Re: QMX RF Filter Sweep (80m) Fails The First Time the Test Is Executed
Yes I have experienced exactly what your describing.?
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Re: QMX+ build: so close, and yet....
Michael
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If you hear? noise in the headphones, that's good. The fact the link is fitted is good. But connect an aerial to check the RX is actually hearing things.
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Your Description of SWR bouncing around is indicative of the same problem I had. If you have a scope check there is a CLK 2 signal.
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What current is drawn when you press T in the diagnostics screen. With my fault (No CLK2)I was seeing very high current 1.2 to 1.5A across the bands.
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73
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Ian G4GIR
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----- Original Message -----
From: Michael - WD0OM via groups.io < wd0om@...>
Sent: 27/09/2024 04:46:05
Subject: Re: [QRPLabs] QMX+ build: so close, and yet....
Brian,
T507 is certainly a possible culprit, as is T501. In my case, it sort of just feels like all the would-be transmit power is falling into a hole, which inclines me more to think T501. I have a feeling that I might also wind up having to desolder and rework one or both to get to good at this point.
On the upside, I have some of the 0.33 wire left, and my shipment (a v2) was early enough that they were mistakenly throwing in some 0.60 still as well. OTOH, I imagine 0.33 isn't that hard or expensive to obtain if it comes down to that level of rework.
Actually: when you reworked T507, did you reuse your existing wire, just straightening it out first?
Thanks for sharing your experience. I don't know if it's the same problem at all, but it's certainly an angle to look at!
Michael WD0OM
On Thu, Sep 26, 2024, at 18:02, Brian wrote:
I'm not qualified to give advice (but I will anyway).? #1 is thank you to everyone here helping and posting.? It allowed me to get my QMX+ working!
?
My first bug was minor- display was blank.? There was a poor solder joint inside the "pin sandwich" display/front board.? I was able to find it with a bright flashlight.
?
The last bug (RX worked great, menus, etc) was (maybe?) similar to yours.? Failing TX due to high SWR into a dummy load- pretty quick too. Different from your experience though- it always TX'ed for a brief time before failing.? I have P/S set to 12V / 250ma to avoid cooking anything, but it still tripped SWR protection on all bands. I fussed and fiddled with T507 and finally threw in the towel.? I removed it and built it over again, being MORE careful to separate the 10-loops from the one-loops.? After that- transmit worked, but I saw the "battery symbol" on the LCD flickering.? YES, I then had to turn the current limit on the P/S up from 250 ma. I haven't even got to the terminal diagnostics, so there may be more tweaks, but at least it is putting power out on all bands now.
?
-KN?N
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QMX RF Filter Sweep (80m) Fails The First Time the Test Is Executed
I'm running 1_00_027 firmware on a Rev. 1 QMX that I recently assembled. Everything seems to be working very well, except I have this strange problem with the RF Filter Sweep Test. When I first run the test from the terminal menu, the first sweep of 80m with "Image:? -2.0" or a similar low magnitude value. There is no refresh key (R) available in this test but if I switch to another band with a press of the "-" or "+" key and then switch back to 80m, the 80m result is normal and all subsequent iterations of the test on all bands produce normal results. If I exit the RF Filter Sweep test, it will fail the first sweep again, if it is re-run.. I can quickly press + followed by - (or - followed by +) in rapid succession when the first sweep starts and then the 80m test passes without waiting for the other sweep to complete.
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Also, except for the first weird sweep, 80m produces "Image: -22.2", which is of significantly lower magnitude that all the other bands but I guess this is common.
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Has anyone here seen this behavior? Is it a bug in the test or a bug in my board? I can post screen captures, if necessary.
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Thanks for all replies!
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Cal -- AD8Q
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Re: QMX mid band build - Continuity between A and B points
Hello Stan,
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After T501 removal:
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- No cont between any of the A and B points in the PCB (same letter or between letters)
- T501 exhibits no cont between P and S
- T501 all P have cont to each other
- T501 all S have cont to each other
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So what¡¯s next? Put T501 in again and pray? What am I missing?
?
Thanks for your help!
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Re: QDX High-Band 15m Low Power
How sure are you of your measurement tool? I had similar low power show up for 15m QDX on an ATU-100 (modded for qrp).
I thought QDX died, as it showed only .2w But when I connected it to an oscilloscope I got the actual power reading of about 5w.
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Re: #putty QMX terminal operations
#putty
With my QMX build I often have to turn the QMX on AFTER plugging the cable into the computer.? Then in windows under device manager it will show up as a new COM port.? Something in the USB initialization isn't happening without a power-cycle on the QMX.
On Thu, Sep 26, 2024 at 9:51?PM Don DeGregori via <ddegreg1= [email protected]> wrote: Using Linux Mint 19.3. Installed puTTY and connected to QMX port. The manual shows
using /dev/tty/ACM0. I tried ACM1instead, Neither work.
Then went to Windows 11 machine and installed puTTY there.
It wanted to pick Com1 and Device Manger at USB heading pulled down
indicating an error. What to do?
?
Don
?
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Re: QMX and FT8CN audio issue - strange issue
Mine works fine leaving the thresholds at their normal default values.? I had to set the FT8CN audio to max, and the Android output volume to near max. (Samsung Galaxy)
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Re: QMX+ build: so close, and yet....
Brian,
T507 is certainly a possible culprit, as is T501. In my case, it sort of just feels like all the would-be transmit power is falling into a hole, which inclines me more to think T501. I have a feeling that I might also wind up having to desolder and rework one or both to get to good at this point.
On the upside, I have some of the 0.33 wire left, and my shipment (a v2) was early enough that they were mistakenly throwing in some 0.60 still as well. OTOH, I imagine 0.33 isn't that hard or expensive to obtain if it comes down to that level of rework.
Actually: when you reworked T507, did you reuse your existing wire, just straightening it out first?
Thanks for sharing your experience. I don't know if it's the same problem at all, but it's certainly an angle to look at!
Michael WD0OM
On Thu, Sep 26, 2024, at 18:02, Brian wrote:
I'm not qualified to give advice (but I will anyway).? #1 is thank you to everyone here helping and posting.? It allowed me to get my QMX+ working!
?
My first bug was minor- display was blank.? There was a poor solder joint inside the "pin sandwich" display/front board.? I was able to find it with a bright flashlight.
?
The last bug (RX worked great, menus, etc) was (maybe?) similar to yours.? Failing TX due to high SWR into a dummy load- pretty quick too. Different from your experience though- it always TX'ed for a brief time before failing.? I have P/S set to 12V / 250ma to avoid cooking anything, but it still tripped SWR protection on all bands. I fussed and fiddled with T507 and finally threw in the towel.? I removed it and built it over again, being MORE careful to separate the 10-loops from the one-loops.? After that- transmit worked, but I saw the "battery symbol" on the LCD flickering.? YES, I then had to turn the current limit on the P/S up from 250 ma. I haven't even got to the terminal diagnostics, so there may be more tweaks, but at least it is putting power out on all bands now.
?
-KN?N
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Re: QMX+ build: so close, and yet....
I'm not qualified to give advice (but I will anyway).? #1 is thank you to everyone here helping and posting.? It allowed me to get my QMX+ working!
?
My first bug was minor- display was blank.? There was a poor solder joint inside the "pin sandwich" display/front board.? I was able to find it with a bright flashlight.
?
The last bug (RX worked great, menus, etc) was (maybe?) similar to yours.? Failing TX due to high SWR into a dummy load- pretty quick too. Different from your experience though- it always TX'ed for a brief time before failing.? I have P/S set to 12V / 250ma to avoid cooking anything, but it still tripped SWR protection on all bands. I fussed and fiddled with T507 and finally threw in the towel.? I removed it and built it over again, being MORE careful to separate the 10-loops from the one-loops.? After that- transmit worked, but I saw the "battery symbol" on the LCD flickering.? YES, I then had to turn the current limit on the P/S up from 250 ma. I haven't even got to the terminal diagnostics, so there may be more tweaks, but at least it is putting power out on all bands now.
?
-KN?N
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Antenna connectors for LightAPRS-W (+WSPR) 2.0 tracker
I just received a ?LightAPRS-W (+WSPR) 2.0 tracker and it looks like the board was designed for sma jacks to be soldered?
for the antenna connections.? Is this correct?? Any suggestions for the right sma connector to use?? I was thinking of something
like this:
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Alternatively, BNC connectors would be ok for my application.? Is there a BNC jack that would work?
?
Thanks.
?
Chris
W6COV
?
?
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Re: Question about bands for "50W Amp for QCX-series"
Hi Stan,
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I too appreciate QRPLabs so much.
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I think this kit amplifier can be built for, at least, up to 10m bands, but several modifications would be in order, to obtain good results on and above 15m.
When I first built it for 10m just changing the LPF capacitor values, the power output was only 4W, and T2 and T3 became untouchably hot.
After modifications, many of which are based upon valuable guidance from Alison, KB1GMX, in this group, I am getting up to 35W with QCX, 28W with QMX+, on 10m.
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I believe it can be built for 6m, also, but have not tried it, yet.
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73, Aki, JO4MTH
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Re: #QMX Loaded FW 27, Now Dead?
#qmx
I finally got some electrolytic caps and soldered 100uF to the 12v input. It helped somewhat with the triangle wave I'd been seeing but it still isn't coming fully alive. I got in with Putty and 5v is still unhappy. All of the buttons and encoders register, so that's good.
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This is what I was seeing before adding the cap:
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Re: Still no output on QMX
<On the face of it the RF power readings are unrealistic>
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What are you saying Don? Let me post a screen shot on 20M. I only provided one on 60M because I couldn't change bands on the unit while plugged into the computer. I only just realized I could change bands inside the puddy app.
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Re: QMX mid band build - Continuity between A and B points
A short between A & B means that either a) somehow the primary and secondary wires of T501 are shorted together, or b) there was a short on the board before you put T501 in.? Most likely a) but check both.
A short between primary & secondary is easy to accidentally do if you scrape too much of the lacquer off the ends of the wires.? Also, sometimes the core itself has some sharp edges just inside the holes on either end - these can scrape the insulation off the wires as you pull them through the core, potentially causing shorts.? You can use a craft knife or a small conical grinding stone from a Dremel tool to carefully 'sand' those edges of the core to make them smooth, so they don't scrape the wires.
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Re: QMX mid band build - Continuity between A and B points
Remove T501 and check again. If there is no continuity, you most likely have a short between the windings of T501 or it may be incorrectly made.
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Al, K2ZN
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David Wilcox K8WPE
Vojislav [YU4HAK]
James
Al Scanandoah