Re: QMX+ build: so close, and yet....
The SWR bridge winding will look like a short at DC, this is normal.
73, Don N2VGU
|
Re: QMX+ build: so close, and yet....
Answering the question from way earlier about whether receiving was working, though, the answer appears to be yes. Granted I'm still just on the dummy load, but I put in headphones and tuned around, and definitely seem to hear signals.
So exactly that much is right?
On Thu, Sep 26, 2024, at 17:20, Michael - WD0OM wrote:
OK, at this point, I'm stumped again.
I have touched up joints all along the BNC-side of the board, all the way down to the infamous BS170s, along with the trifilar which looked very iffy.
It all still seems to be behaving about the same -- which is to say, not right.
Picking 20m this time as a specific target, when I hit T:
BIAS SMPS current goes red, 61.3 mA, duty cycle is 0%
Transmitter voltage bounces between 10.3 (which its fine with) and 10.4 (which goes red)
Power is 0.0W
SWR, as I said earlier, bounces all over the place.
Supply, 3.3V SMPS, and 5V SMPS all are green and nominal where they belong: 12.3V, 3.3V, 5V, duty cycles all green.
What's the next thing to look at?
Thank you all!
Michael WD0OM
|
QDX High-Band 15m Low Power
On my second QDX build, this one the high-band model, I'm getting consistent 5w (+/- .2w) for all bands except on 15, which is at 1.5w.? The LPF curve in terminal looks good with the peak close to centered on the band.? I have updated firmware, restarted, and same behavior.
Rechecked LPF toroid winding counts, looked over solder joints for anything out of place, etc.? L12 (tapped inductor) winding counts checked (is there a 15m-specific tap that might have a cold solder joint?).? T2 (trifilar toroid) continuity rechecked.
Any thoughts on where to focus the search?
?
thx!
?
Dave
WI9Q
|
Re: QMX+ build: so close, and yet....
OK, at this point, I'm stumped again.
I have touched up joints all along the BNC-side of the board, all the way down to the infamous BS170s, along with the trifilar which looked very iffy.
It all still seems to be behaving about the same -- which is to say, not right.
Picking 20m this time as a specific target, when I hit T:
BIAS SMPS current goes red, 61.3 mA, duty cycle is 0%
Transmitter voltage bounces between 10.3 (which its fine with) and 10.4 (which goes red)
Power is 0.0W
SWR, as I said earlier, bounces all over the place.
Supply, 3.3V SMPS, and 5V SMPS all are green and nominal where they belong: 12.3V, 3.3V, 5V, duty cycles all green.
What's the next thing to look at?
Thank you all!
Michael WD0OM
|
Re: Still no output on QMX
| ? |
QMX Diagnostic Results Idle |
| ? |
? |
? |
? |
? |
? |
? |
? |
? |
| ? |
Bench Supply 9V |
? |
Diagnostic Screen |
| ? |
? |
? |
? |
? |
? |
? |
? |
? |
| Band |
Voltage |
Current? |
SWR |
Voltage |
PA 3V3 |
PA 5V |
SWR |
Bias SMPS |
| ? |
? |
? |
? |
? |
? |
? |
? |
? |
| 60M |
9V |
0.112 |
1:1 |
.3V |
3.34 |
5 |
? |
Off |
| 40M |
9V |
0.112 |
1:1 |
.3V |
3.34 |
5 |
? |
Off |
| 30M |
9V |
0.112 |
1:1 |
.3V |
3.34 |
5 |
? |
Off |
| 20M |
9V |
0.112 |
1:1 |
.3V |
3.34 |
5 |
? |
Off |
| 17M |
9V |
0.112 |
1:1 |
.3V |
3.34 |
5 |
? |
Off |
| 15M |
9V |
0.112 |
1:1 |
.3V |
3.34 |
5 |
? |
Off |
| ? |
? |
? |
? |
? |
? |
? |
? |
? |
| ? |
? |
? |
? |
? |
? |
? |
? |
? |
| ? |
QMX Diagnostic Results "P" |
| ? |
? |
? |
? |
? |
? |
? |
? |
? |
| ? |
Bench Supply 9V |
? |
Diagnostic Screen |
| ? |
? |
? |
? |
? |
? |
? |
? |
? |
| Band |
Voltage |
Current? |
SWR |
Voltage |
Bias SMPS |
Power |
SWR |
Bias SMPS |
| ? |
? |
? |
? |
? |
? |
? |
? |
? |
| 60M |
9V |
0.127 |
1:1 |
.3V |
30.3 |
? |
? |
On |
| 40M |
9V |
0.129 |
1:1 |
.3V |
30.4 |
? |
? |
On |
| 30M |
9V |
0.13 |
1:1 |
.3V |
30.4 |
? |
? |
On |
| 20M |
9V |
0.132 |
1:1 |
.3V |
30.4 |
? |
? |
On |
| 17M |
9V |
0.133 |
1:1 |
.3V |
30.4 |
? |
? |
On |
| 15M |
9V |
0.134 |
1:1 |
.3V |
30.4 |
? |
? |
On |
| ? |
? |
? |
? |
? |
? |
? |
? |
? |
| ? |
? |
? |
? |
? |
? |
? |
? |
? |
| ? |
QMX Diagnostic Results "T" |
| ? |
? |
? |
? |
? |
? |
? |
? |
? |
| ? |
Bench Supply 9V |
? |
Diagnostic Screen |
| ? |
? |
? |
? |
? |
? |
? |
? |
? |
| Band |
Voltage |
Current? |
SWR |
Voltage |
Bias SMPS |
Power |
SWR |
Bias SMPS |
| ? |
? |
? |
? |
? |
? |
? |
? |
? |
| 60M |
9V |
0.92 |
1:1 |
7.2 |
30.5 |
<.5 W |
2.53 |
On |
| 40M |
9V |
0.803 |
1:1 |
7.3 |
30.5 |
<.5 W |
2.7 |
On |
| 30M |
9V |
0.942 |
1:1 |
7.2 |
30.5 |
<.5 W |
2.67 |
On |
| 20M |
9V |
0.84 |
1:1 |
7.4 |
30.5 |
9.6 W |
2.66 |
On |
| 17M |
9V |
0.872 |
1:1 |
7.4 |
30.5 |
8.6 W |
2.62 |
On |
| 15M |
9V |
1.001 |
1:1 |
7.1 |
30.5 |
5.2 W |
2.54 |
On |
?
?
I brought the Display back by shorting out the "Force Firmware Update" pins
|
Re: QMX+ build: so close, and yet....
Sorry, misspoke -- it was not T501 I touched up, it was the Trifilar.
On Thu, Sep 26, 2024, at 16:50, Michael Scott Shappe wrote:
I also just touched up T501's joints. No real help.
Transmit diagnostics still show 0W, and 10-ish V (which I think is low). SWR bounces around between 1 and 5 but never constant.
On Thu, Sep 26, 2024, at 16:47, Michael - WD0OM wrote:
Yeah, I'd noticed those were iffy, too. I touched them up. No real help, there. Same results when I powered back on and ran the diag.
On Thu, Sep 26, 2024, at 16:41, Roger Hill wrote:
Get
On 26 Sept 2024, at 17:40, Roger Hill < rhill@...> wrote: The joint top right in your pic is not soldered well, and the one top left, 2 down, also looks suspicious.
73
Roger
Get BlueMail for Android
On 26 Sept 2024, at 17:15, Michael - WD0OM < wd0om@...> wrote: Here is the area in question, zoomed in from my phone camera.?
On Thu, Sep 26, 2024, at 16:07, Michael - WD0OM wrote:
OK, so: the jumper wire looks good. So far, most of my other joints also look good.
The BNC connector itself though, I get continuity between the four ground pins, and the fifth middle pin which I assume is the signal pin. I'm pretty sure I should not have continuity there!
There are no obvious bridges, so I may have to actually try to rework the whole part. I'm open to suggestions :-D
Meanwhile, I will keep looking for other areas of the board touchups might be needed!
On Thu, Sep 26, 2024, at 11:05, Michael - WD0OM wrote:
I'm pretty sure I did add that jumper....but that doesn't mean it's right :-D I will check it!
On Thu, Sep 26, 2024, at 10:37, Greg McCain via groups.io wrote:
I think Ian was asking about the jumper wire on the main PCB that has to be installed to get the RF signals in and out of the BNC connector.
It's described in the assembly manual on the same page as the 'Wind and install transformer T501' instructions.?
|
Re: QMX+ build: so close, and yet....
I also just touched up T501's joints. No real help.
Transmit diagnostics still show 0W, and 10-ish V (which I think is low). SWR bounces around between 1 and 5 but never constant.
On Thu, Sep 26, 2024, at 16:47, Michael - WD0OM wrote:
Yeah, I'd noticed those were iffy, too. I touched them up. No real help, there. Same results when I powered back on and ran the diag.
On Thu, Sep 26, 2024, at 16:41, Roger Hill wrote:
Get
On 26 Sept 2024, at 17:40, Roger Hill < rhill@...> wrote: The joint top right in your pic is not soldered well, and the one top left, 2 down, also looks suspicious.
73
Roger
Get BlueMail for Android
On 26 Sept 2024, at 17:15, Michael - WD0OM < wd0om@...> wrote: Here is the area in question, zoomed in from my phone camera.?
On Thu, Sep 26, 2024, at 16:07, Michael - WD0OM wrote:
OK, so: the jumper wire looks good. So far, most of my other joints also look good.
The BNC connector itself though, I get continuity between the four ground pins, and the fifth middle pin which I assume is the signal pin. I'm pretty sure I should not have continuity there!
There are no obvious bridges, so I may have to actually try to rework the whole part. I'm open to suggestions :-D
Meanwhile, I will keep looking for other areas of the board touchups might be needed!
On Thu, Sep 26, 2024, at 11:05, Michael - WD0OM wrote:
I'm pretty sure I did add that jumper....but that doesn't mean it's right :-D I will check it!
On Thu, Sep 26, 2024, at 10:37, Greg McCain via groups.io wrote:
I think Ian was asking about the jumper wire on the main PCB that has to be installed to get the RF signals in and out of the BNC connector.
It's described in the assembly manual on the same page as the 'Wind and install transformer T501' instructions.?
|
Re: QMX+ build: so close, and yet....
Yeah, I'd noticed those were iffy, too. I touched them up. No real help, there. Same results when I powered back on and ran the diag.
On Thu, Sep 26, 2024, at 16:41, Roger Hill wrote:
Get
On 26 Sept 2024, at 17:40, Roger Hill < rhill@...> wrote: The joint top right in your pic is not soldered well, and the one top left, 2 down, also looks suspicious.
73
Roger
Get BlueMail for Android
On 26 Sept 2024, at 17:15, Michael - WD0OM < wd0om@...> wrote: Here is the area in question, zoomed in from my phone camera.?
On Thu, Sep 26, 2024, at 16:07, Michael - WD0OM wrote:
OK, so: the jumper wire looks good. So far, most of my other joints also look good.
The BNC connector itself though, I get continuity between the four ground pins, and the fifth middle pin which I assume is the signal pin. I'm pretty sure I should not have continuity there!
There are no obvious bridges, so I may have to actually try to rework the whole part. I'm open to suggestions :-D
Meanwhile, I will keep looking for other areas of the board touchups might be needed!
On Thu, Sep 26, 2024, at 11:05, Michael - WD0OM wrote:
I'm pretty sure I did add that jumper....but that doesn't mean it's right :-D I will check it!
On Thu, Sep 26, 2024, at 10:37, Greg McCain via groups.io wrote:
I think Ian was asking about the jumper wire on the main PCB that has to be installed to get the RF signals in and out of the BNC connector.
It's described in the assembly manual on the same page as the 'Wind and install transformer T501' instructions.?
|
Re: QMX+ build: so close, and yet....
Sorry, 3 down.
Roger
Get
On 26 Sept 2024, at 17:40, Roger Hill < rhill@...> wrote:
The joint top right in your pic is not soldered well, and the one top left, 2 down, also looks suspicious.
73
Roger
8P6RX
Get BlueMail for Android
On 26 Sept 2024, at 17:15, Michael - WD0OM < wd0om@...> wrote:
Here is the area in question, zoomed in from my phone camera.?
On Thu, Sep 26, 2024, at 16:07, Michael - WD0OM wrote:
OK, so: the jumper wire looks good. So far, most of my other joints also look good.
The BNC connector itself though, I get continuity between the four ground pins, and the fifth middle pin which I assume is the signal pin. I'm pretty sure I should not have continuity there!
There are no obvious bridges, so I may have to actually try to rework the whole part. I'm open to suggestions :-D
Meanwhile, I will keep looking for other areas of the board touchups might be needed!
On Thu, Sep 26, 2024, at 11:05, Michael - WD0OM wrote:
I'm pretty sure I did add that jumper....but that doesn't mean it's right :-D I will check it!
On Thu, Sep 26, 2024, at 10:37, Greg McCain via groups.io wrote:
I think Ian was asking about the jumper wire on the main PCB that has to be installed to get the RF signals in and out of the BNC connector.
It's described in the assembly manual on the same page as the 'Wind and install transformer T501' instructions.?
|
Re: QMX+ build: so close, and yet....
The joint top right in your pic is not soldered well, and the one top left, 2 down, also looks suspicious.
73
Roger
8P6RX
Get BlueMail for Android
On 26 Sept 2024, at 17:15, Michael - WD0OM < wd0om@...> wrote:
Here is the area in question, zoomed in from my phone camera.?
On Thu, Sep 26, 2024, at 16:07, Michael - WD0OM wrote:
OK, so: the jumper wire looks good. So far, most of my other joints also look good.
The BNC connector itself though, I get continuity between the four ground pins, and the fifth middle pin which I assume is the signal pin. I'm pretty sure I should not have continuity there!
There are no obvious bridges, so I may have to actually try to rework the whole part. I'm open to suggestions :-D
Meanwhile, I will keep looking for other areas of the board touchups might be needed!
On Thu, Sep 26, 2024, at 11:05, Michael - WD0OM wrote:
I'm pretty sure I did add that jumper....but that doesn't mean it's right :-D I will check it!
On Thu, Sep 26, 2024, at 10:37, Greg McCain via groups.io wrote:
I think Ian was asking about the jumper wire on the main PCB that has to be installed to get the RF signals in and out of the BNC connector.
It's described in the assembly manual on the same page as the 'Wind and install transformer T501' instructions.?
|
Re: QMX+ build: so close, and yet....
This question comes up from time to time.? The measured short across the center pin of the BNC to ground is normal due to one of the windings of T507 going across the BNC output to ground.? Of course, you could also have a short from the BNC hot side to a ground pin of the SMA footprint but your soldering looks OK here.
-Steve K1RF
------ Original Message ------
Date 9/26/2024 5:15:14 PM
Subject Re: [QRPLabs] QMX+ build: so close, and yet....
Here is the area in question, zoomed in from my phone camera.?
On Thu, Sep 26, 2024, at 16:07, Michael - WD0OM wrote:
OK, so: the jumper wire looks good. So far, most of my other joints also look good.
The BNC connector itself though, I get continuity between the four ground pins, and the fifth middle pin which I assume is the signal pin. I'm pretty sure I should not have continuity there!
There are no obvious bridges, so I may have to actually try to rework the whole part. I'm open to suggestions :-D
Meanwhile, I will keep looking for other areas of the board touchups might be needed!
On Thu, Sep 26, 2024, at 11:05, Michael - WD0OM wrote:
I'm pretty sure I did add that jumper....but that doesn't mean it's right :-D I will check it!
On Thu, Sep 26, 2024, at 10:37, Greg McCain via groups.io wrote:
I think Ian was asking about the jumper wire on the main PCB that has to be installed to get the RF signals in and out of the BNC connector.
It's described in the assembly manual on the same page as the 'Wind and install transformer T501' instructions.?
|
Re: QMX+ build: so close, and yet....
OK, so that's a red herring. Good to know, I guess!
Next up then I guess is to look more closely at the T507 itself.
On Thu, Sep 26, 2024, at 16:18, ZL1SGS wrote:
Don't worry about the DC continuity across the BNC - there's a DC path through T507 (I think thats the one), but ok at RF.
|
Re: QMX+ build: so close, and yet....
Don't worry about the DC continuity across the BNC - there's a DC path through T507 (I think thats the one), but ok at RF.
|
Re: QMX+ build: so close, and yet....
Here is the area in question, zoomed in from my phone camera.?
On Thu, Sep 26, 2024, at 16:07, Michael - WD0OM wrote:
OK, so: the jumper wire looks good. So far, most of my other joints also look good.
The BNC connector itself though, I get continuity between the four ground pins, and the fifth middle pin which I assume is the signal pin. I'm pretty sure I should not have continuity there!
There are no obvious bridges, so I may have to actually try to rework the whole part. I'm open to suggestions :-D
Meanwhile, I will keep looking for other areas of the board touchups might be needed!
On Thu, Sep 26, 2024, at 11:05, Michael - WD0OM wrote:
I'm pretty sure I did add that jumper....but that doesn't mean it's right :-D I will check it!
On Thu, Sep 26, 2024, at 10:37, Greg McCain via groups.io wrote:
I think Ian was asking about the jumper wire on the main PCB that has to be installed to get the RF signals in and out of the BNC connector.
It's described in the assembly manual on the same page as the 'Wind and install transformer T501' instructions.?
|
Re: QMX+ build: so close, and yet....
OK, so: the jumper wire looks good. So far, most of my other joints also look good.
The BNC connector itself though, I get continuity between the four ground pins, and the fifth middle pin which I assume is the signal pin. I'm pretty sure I should not have continuity there!
There are no obvious bridges, so I may have to actually try to rework the whole part. I'm open to suggestions :-D
Meanwhile, I will keep looking for other areas of the board touchups might be needed!
On Thu, Sep 26, 2024, at 11:05, Michael - WD0OM wrote:
I'm pretty sure I did add that jumper....but that doesn't mean it's right :-D I will check it!
On Thu, Sep 26, 2024, at 10:37, Greg McCain via groups.io wrote:
I think Ian was asking about the jumper wire on the main PCB that has to be installed to get the RF signals in and out of the BNC connector.
It's described in the assembly manual on the same page as the 'Wind and install transformer T501' instructions.?
|
Re: QMX mid band build - Continuity between A and B points
Excellent advice. Though, QRP Guys is closed until early December. I built one of their SWR/Power Meters. Great kit. I'm going to order a 2nd one when they open back up for sure.?
I also bought and built a QRPometer from NM0S. Google NM0S QRPometer and find his Tindie site to order. Uses ax resistive bridge so the XCVR never sees more than? 2:1 SWR.?
|
You may remove parts from VDD rail one by one until the fault is gone or check the VDD rail using a good ohm meter with milli ohm resolution.
?
?
I will leave that for weekend task, until then i am looking at overpriced ikebana on my desk.
|
Re: QMX mid band build - Continuity between A and B points
If you do make another order from qrp-labs.com,
?
In addition to a few extra bs170 and toroids, buy the
$8.50?
50-ohm 20W QRP HF Dummy Load
very inexpensive and very useful.
?
If you like building kits consider:
$40
?
Hans has a video on how to tweak the toroid coils for maximum power.
He uses a scope,? but if you do not have a scope the? above device will read out watts.
It does not matter if it is accurate.? It only matters in determining if? collapsing winding? ?is better than spreading winding.
The above device can be used for that measurement.
?
If you are into qrp from remote sites the following
kit tuner was nice:
$45
?
?
stan ag5vh
?
?
?
|
Re: QMX mid band build - Continuity between A and B points
Wind toroids using the chopstick method others have recommended.
?
Only wind toroids over carpet floors.? Inevitably, you and everyone else will drop them.
They are ceramic and will shatter if you drop them on a tile floor.? Hans buys them in? the thousands, you will not find replacements easily.
If you have a reason to make an extra order from qrp-labs.com buy some extra from the spar parts section.
?
Those 47uh axial are more delicate then similar sized resistors -bend leads without applying pressure to body.
?
Everybody including me have been fixated with heat dissipation of the bs170.? Don't bother with extra heat sinks.
Some of the problems with? damaging the bs170 was from very early software versions.? Newer software versions
have high SWR protection.? Just do not disable the SWR protection.? ?The heat is dissipated thru the leads and not the plastic.
?
Some of the assembly has to be done in the exact order.? Solder has both an electrical, and mechanical purpose.
If you solder before everything is aligned? it will not end well.? I am referring to the connectors on the two power boards,?
and the connectors that extend thru the optional case.? ?
?
You have one chance to bend the leads of the encoder in the correct direction- which is probably opposite of what you would think.
I think I just soldered scrap wire to make the connection?
?
?
stan ag5vh
|
Re: Question about bands for "50W Amp for QCX-series"
Hans has posted design info somewhere on its max useful frequency. It's limited by the inexpensive power transistors.?
?
It's also a class C design, not suitable for SSB.?
?
Note also the low pass filters need larger toroids and wire than the qrp filters qrp-labs sells. A few folk have built theirs to use external low pass filters, or even cascading a second external one.?
?
Curt
?
|
Donald S Brant Jr
James
ZL1SGS
Ivica - YU1QRP