Re: QMX practice mode suggestions
Hello Chelin, in digital modes it works in USB, I only do CW and my question is if I should change the mode to CW-R like I do on the K2, Ft817, Xiegu X6100 etc? Luis LU4HK - L73H
El vie, 20 sept 2024 a la(s) 9:36?a.m., Bob Parr via (parr= [email protected]) escribió: So it is just a way to allow the radio to function only without transmitting?? I see why that would be helpful for CW, but not so much for digital modes.
?
Bob
KG5GTE
|
Re: QMX practice mode suggestions
So it is just a way to allow the radio to function only without transmitting?? I see why that would be helpful for CW, but not so much for digital modes.
?
Bob
KG5GTE
|
Hello everyone !! I'm Luis LU4HK, and I have a question with my QMX 40-20.
When I use the 80-60 and 40 meter bands, I must change the configuration to CW-R or the mode is recognized by default.
72 Luis FF78lg
|
Re: QMX (not-plus) power issue
On Thu, Sep 19, 2024 at 10:22 PM, Michael - WD0OM wrote:
with what look to be calibration screws under the needle display.
Those are usually mechanical meter zeroing adjustment screws, for zero setting, not calibration.
73, Don N2VGU
|
Re: Solder iron tip recommendations
There is no one-size-fits-all answer, indeed, I have used 2 or 3 different irons/tips on a single board, depending upon the PCB involved.? Smaller pins/components with tighter spacing need a smaller, perhaps conical tip, whereas a larger, ground pin or TO-220 part may need a larger chisel type at a higher temperature.? You may need yet a third to solder large power conductors or RF connectors.?
I have 3 soldering stations and many different tips on my assembly bench and I have had them all in play on a single project.
?
One thing which will help is the application of background heat to the board; it will make soldering much easier and is actually less stressful to chip components as the board and components cool and contract.? Even putting it onto a 100°C hot plate helps immensely.
?
73, Don N2VGU
|
Ultimate3S has started crashing during transmission.
We have a Ultimate3S running at the club and has been running with no problems for over a year. For some reason it will start it's transmission sequence and at the end of the first transmission it appears to crash and not finish. Firmware is still running after the crash and will attempt the transmission sequence again at the next half hour mark but will fail. It's configured to TX from 10m down to 80m (10, 15, 20, 40, 80 starting on the half hour. Some will start the sequence and fail part way through and occasionally it will complete and carry on for several hours then fail.
nothing has changed and is not running excessively hot.
Any help, suggestions would be greatly appreciated.?
|
Re: QMX+ V2 - I've killed it
Check to see if the metal edge of the left encoder is touching the top of the barrel socket on the main board. Hans suggested covering that with tape to prevent that possibility.
--
73, Dan - W2DLC
|
Re: QMX (not-plus) power issue
Some helpful numbers to post would be the voltage you built your QMX for, and what is the overall input current draw in receive mode of your QMX??
?
For a 12v QMX you should see around 90 mA or so of current when it's on and idle (not transmitting).?
?
If it's substantially more than 90mA then your power meter is likely correct, and one of the output power transistors is likely blown/defective.... As a first diagnostic guess.?
--
73
de Roy - KI0ER
Littleton, Colorado USA
|
Re: Thinking about a project, receiver module + VFO / sig gen
On 19/09/2024 21:01, Eric Hansen, KB1VUN via groups.io wrote: As a bonus, I though it might be fun to see if I could make a VHF (FM broadcast, NOAA, 2m ham) receiver.? That's the reason for asking about the wider tuning range. Eric, I certainly can't help with coding:-) The Softrock/QRP Labs RXs are limited by the hardware which, I think, will not go much above 60-70MHz. So to use them at VHF you would need a mixer or tuner chip in front. An example here 73 Alan G4ZFQ
|
Re: qmx+ SCHEMATIC QUESTION hELP UNDERSTANDING
I have the New PCB with the power supplies on the main board. I will inspect everything again.
?Steve where didyou make connection for the D103 ??
?I am thinking , mine on top of the PCB? IC101 output to a nearby VDD JP106 hole.
?
I am unclear if that is correct,? ain't done it yet.
Lee,
?AA7HC
?
?
|
Re: QMX+ V2 - I've killed it
Thanks again all. I can’t connect to my PC at all. No signs of shorts to the case internally but I can’t rule that out as the cause.?
I’ll order replacements for Q3 and Q5 and see how that goes. Wonder if it’s worth ordering some other components that might also need replacement. Hm… which ones?
I had to replace the 5V board on another QMX recently due to a scratchy 12V supply - the bad connection there was on the external PSU, and the simple board swap fixed it. Not quite so easy with the SMPSUs being integrated into the main board with V2. In that case I was able to connect to the terminal and see that the 5V board was dead.?
Steve MW0KST
|
Re: QMX+ Filter Cascading Question
Thanks Stan.? Actually those first two sentences are the lightbulb on how to use the filters!? Much appreciated.
?
N4TTU - TL
|
Re: qmx+ SCHEMATIC QUESTION hELP UNDERSTANDING
Stan - good point. A physical connection between +12V and VDD could blow up D103. A couple components that are just a bit too close is all it would take to set up a failure mode when the main board is flexed a bit.
My QMX+ is still waiting to be built. I did fix a QMX+ for my good friend Rich N3III a week ago. The problem with his radio was traced to a missing D103. Looked like it was ripped from the board, along with its pads. Fortunately that was easy to fix, and his QMX+ is working super-well now.
73, Steve, N3SB?
toggle quoted message
Show quoted text
-------- Original message -------- From: Stan Dye <standye@...> Date: 9/19/24 10:44 PM (GMT-05:00) Subject: Re: [QRPLabs] qmx+ SCHEMATIC QUESTION hELP UNDERSTANDING
A momentary short from the 12V bus to VDD could blow up D103.? Is there something mechanically close that could come together and short these two? Maybe pins contacting the chassis? I don't have QMX+, I got QMXmini, so I can't directly check.
Lee;
Wow - that 3.6 Volt Zener should not have seen an overstress condition sitting on the 3.3 Volt VDD bus - unless the switching regulator did something it shouldn't have.
Looking forward to hearing about the result you obtain when the D109 is replaced.
73; Steve, N3SB?
-------- Original message -------- Date: 9/19/24 8:54 PM (GMT-05:00) Subject: Re: [QRPLabs] qmx+ SCHEMATIC QUESTION hELP UNDERSTANDING
Steve,
?Thanks for the info.? I checked the ground to vcc and showed 330 ohms.? found D109 Zener Diode exploded.on one end. I did get a voltage reading of 2.1 volts. on it though.
?I removed D109? and the ground is gone.
?Mouser Parts on order.?
?I will update this when I get the part.
?Thanks for the help.
?Lee
AA7HC
|
Re: qmx+ SCHEMATIC QUESTION hELP UNDERSTANDING
Get new p/s boards! I tried repairing them and there ended up being additional issues. I don't think it's worth risking damage to the main boards with repaired p/s boards.
?
Check your Vdd and Vcc resistances (with p/s's removed) to make sure you didn't damage the main board.?
--
73, Dan? NM3A
|
Re: qmx+ SCHEMATIC QUESTION hELP UNDERSTANDING
A momentary short from the 12V bus to VDD could blow up D103.? Is there something mechanically close that could come together and short these two? Maybe pins contacting the chassis? I don't have QMX+, I got QMXmini, so I can't directly check.
Lee;
Wow - that 3.6 Volt Zener should not have seen an overstress condition sitting on the 3.3 Volt VDD bus - unless the switching regulator did something it shouldn't have.
Looking forward to hearing about the result you obtain when the D109 is replaced.
73; Steve, N3SB?
-------- Original message -------- Date: 9/19/24 8:54 PM (GMT-05:00) Subject: Re: [QRPLabs] qmx+ SCHEMATIC QUESTION hELP UNDERSTANDING
Steve,
?Thanks for the info.? I checked the ground to vcc and showed 330 ohms.? found D109 Zener Diode exploded.on one end. I did get a voltage reading of 2.1 volts. on it though.
?I removed D109? and the ground is gone.
?Mouser Parts on order.?
?I will update this when I get the part.
?Thanks for the help.
?Lee
AA7HC
|
Re: QMX+ V2 - I've killed it
Since you both heard a 'crackle':
I think about the only thing that could crackle with movement of the QCX in receive mode is a mostly direct short between the input 12V and ground.? This could come from the board flexing a bit and something on the board contacting the chassis (or similar mechanical movement).? I would first visually inspect very carefully with board in chassis to see what could possibly touch where it is not supposed to. Current flow for such a short would go mainly through Q105 and Q103, possibly frying one or both of them.? It would be reasonably easy to check the +12V rail at one of the power jumper blocks, or better at the input and output of Q105 when you try to power on.? If you see a good 12V at all of those spots, the problem is elsewhere - but from what you are saying, it's likely in that area of the circuit.
|
Re: qmx+ SCHEMATIC QUESTION hELP UNDERSTANDING
Lee;
Wow - that 3.6 Volt Zener should not have seen an overstress condition sitting on the 3.3 Volt VDD bus - unless the switching regulator did something it shouldn't have.
Looking forward to hearing about the result you obtain when the D109 is replaced.
73; Steve, N3SB?
toggle quoted message
Show quoted text
-------- Original message -------- From: harleyleenuke <vfrank59@...> Date: 9/19/24 8:54 PM (GMT-05:00) Subject: Re: [QRPLabs] qmx+ SCHEMATIC QUESTION hELP UNDERSTANDING
Steve,
?Thanks for the info.? I checked the ground to vcc and showed 330 ohms.? found D109 Zener Diode exploded.on one end. I did get a voltage reading of 2.1 volts. on it though.
?I removed D109? and the ground is gone.
?Mouser Parts on order.?
?I will update this when I get the part.
?Thanks for the help.
?Lee
AA7HC
|
Re: QMX (not-plus) power issue
By the way, I will accept the possibility that the meter might need calibration! It's literally brand new, out of the box, and it's a cross-needle type with what look to be calibration screws under the needle display. If we think we can trust the diagnostic's idea of what the power output is (even if it's not what it should be on a given band), I will use that as my standard to calibrate and eliminate one mystery!
On Thu, Sep 19, 2024, at 21:19, Michael - WD0OM wrote:
A couple of weeks ago, I think, I brought up an issue I'd seen with my QMX low-band (20-80), where I was only getting about 1.2W out on 20 meters.
Today, I decided to run some tests using a new power meter and dummy load, and also to see if maybe I'd set a setting wrong.
The results were a little surprising, and probably point to some hardware fault, and not a setting problem. To double-check that theory, I did a factory reset and a firmware upgrade, and received the same results.
I have both narrated video of the power meter, and screen recordings of the terminal app, that I can edit together if they would be useful. I had been thinking of terms of posting a YouTube video about "fixing it" but then, of course, I was not able to fix it!
(That said, I may at some point do a YouTube video guided tour of the Terminal App!)
What I'm seeing when I hit the 'T' key in the Diagnostics screen:
Input voltage looks steady at 11.7
SMPS 3.3V shows 3.3V, 5V shows 5V, Bias SMPS shows 30mA as does PIN Bias
For all of these -- and this may be the hint -- the transmitter voltage shows 10.2 transmitting, 0.6 idle
80m: Diagnostics show 4.7W, power meter shows 2.0
60m: Diagnostics show 5W, power meter shows 3
40m: Diagnostics show 4.3W, power meter shows 2.5
30m: Diagnostics show 2.5W, power meter shows 1.25
20m: Diagnostics show 1.2-1.3W, power meter shows 0.5
Where is the most likely place to look for both the shortfall relative to the meter, and the shortfall relative to general expectations of 5W as opposed to 1.2?
Thanks!
Michael WD0OM
|
QMX (not-plus) power issue
A couple of weeks ago, I think, I brought up an issue I'd seen with my QMX low-band (20-80), where I was only getting about 1.2W out on 20 meters.
Today, I decided to run some tests using a new power meter and dummy load, and also to see if maybe I'd set a setting wrong.
The results were a little surprising, and probably point to some hardware fault, and not a setting problem. To double-check that theory, I did a factory reset and a firmware upgrade, and received the same results.
I have both narrated video of the power meter, and screen recordings of the terminal app, that I can edit together if they would be useful. I had been thinking of terms of posting a YouTube video about "fixing it" but then, of course, I was not able to fix it!
(That said, I may at some point do a YouTube video guided tour of the Terminal App!)
What I'm seeing when I hit the 'T' key in the Diagnostics screen:
Input voltage looks steady at 11.7
SMPS 3.3V shows 3.3V, 5V shows 5V, Bias SMPS shows 30mA as does PIN Bias
For all of these -- and this may be the hint -- the transmitter voltage shows 10.2 transmitting, 0.6 idle
80m: Diagnostics show 4.7W, power meter shows 2.0
60m: Diagnostics show 5W, power meter shows 3
40m: Diagnostics show 4.3W, power meter shows 2.5
30m: Diagnostics show 2.5W, power meter shows 1.25 20m: Diagnostics show 1.2-1.3W, power meter shows 0.5
Where is the most likely place to look for both the shortfall relative to the meter, and the shortfall relative to general expectations of 5W as opposed to 1.2?
Thanks!
Michael WD0OM
|
Re: Winding toroids with a chopstick?
This subject seemed exhaustive.? After reading all the points made, I've almost decided on three best practices to use for winding a toroid: - Wind a larger toroid with a small vise.
- Wind a small toroid on a chopstick held in a small vise.
- Wind with a small polished plastic crochet hook when it's decided to use a crochet hook.
- Follow directions about winding multi-filar coils, coils with taps or binocular forms.
- Always stop to consider which direction to wind onto the toroid so as to orient it onto a circuit board, match solder points and the planned vision.
- And, never underestimate other's imaginations!
I am impressed with your skills.
On Tuesday, September 17th, 2024 at 19:53, Karl via groups.io <karlshumaker@...> wrote:
Great idea! I used crochet hooks on the QMX+ toroids and they wound fast anf tight.
--
73
Karl
KI4ZUQ
|
Donald S Brant Jr
Dave, G8PGO
Daniel Conklin
Tom Lewis - N4TTU