Keyboard Shortcuts
ctrl + shift + ? :
Show all keyboard shortcuts
ctrl + g :
Navigate to a group
ctrl + shift + f :
Find
ctrl + / :
Quick actions
esc to dismiss
Likes
- QRPLabs
- Messages
Search
Re: ProgRock2 programming??
Two comments here:
?
- Yes, the ProgRock2 (nor the original) have coupling capacitors on their outputs.? If you aren't sure if you need one, add one!? Don't go overboard with the capacitance - perhaps a value that will provide an Xc (reactance) equal to or greater than 1/3 of the expected load impedance at the lowest frequency.?
?
- Even though they are "rated" for "12 volts" don't even think about running one at that voltage:? I'd avoid going above 10.0 volts.? Either put a voltage regulator there (anything from 5 to 10 volts is fine - there's no point in more than 5) or if you do have a fairly stable 10-12 volts, a 47-68 ohm, 1/2 watt resistor in series with each (expect 40-60mA consumption - do the math) to limit the voltage.? I "discovered" that even when running from 12.0 volts (from a 7812) that the ProgRock ran very hot - and two of them failed in quick succession, hence the warning.? 5.0-9.0 volts is more or less the sweet spot.
?
73,
?
Clint, KA7OEI
? |
Re: Qmx plus rev 2 not powering up
Hi Ludwig
I have ordered the correct Mosfets should arrive tomorrow, I will measure the LIN_REG_EN and then solder the mosfets, just to confirm the LIN_REG_EN should be 12V when the button is pressed in hardware version QMX+ if QMX (No +) with different revisions might have only 6V, correct?
?
73 Azgael |
Re: Low current BIAS SMPS
Or actually not! It looks as if the transistor had been in place and fallen off. When this did happen cannot be said. It even would have been possible to pass a function test.? I’m happy that it was possible to fix it easily. This even makes building the kit more fun. The next days I will run further tests to see what I might have done wrong. But I really love the stacked design and the great debugging utility. It’s a great piece of tec! Love it! |
Re: ProgRock2 programming??
I didn't add one. How does it work without some DC going to pad 6 of the unit? It seems the unit would need the pad 6 to be connected to a voltage source. Tom
On Wednesday, April 2, 2025 at 09:16:32 AM CDT, Alan G4ZFQ via groups.io <alan4alan@...> wrote:
On 02/04/2025 13:54, Tom Smith via groups.io wrote: > I plugged it into the equipment and it seemed to work for a few minutes then stopped. I’m not sure why but I’ll set up another unit for another frequency and see if it does the same thing. It may be something in the equipment oscillator circuitry killing the PR2 (maybe a voltage issue) Tom, I think I'm right in saying there are no isolation capacitors on the Progrock's outputs. I hope you added one. Any voltage on the equipment's crystal socket could damage the 5351. 73 Alan G4ZFQ |
Re: Debugging BS170-related issues
toggle quoted message
Show quoted text
From: [email protected] <[email protected]> on behalf of Steve N2IC via groups.io <n2icarrl@...>
Sent: Wednesday, April 2, 2025 8:17 AM To: [email protected] <[email protected]> Subject: Re: [QRPLabs] Debugging BS170-related issues ?
This is probably a stupid question with an obvious answer, but I don't want to screw it up....
?
Received replacement parts from Digikey. Removed old IC503 without incident (first time using ChipQuik).
?
The replacement 74ACT08SC-ND does not have the standard pin 1 dot I have come to expect on an IC. It does have a solid, white bar. Can I assume that is the pin 1 dot ?
?
Thanks and 73,
Steve, N2IC
|
Re: Low current BIAS SMPS
Reminds me that an automated comparison of board images taken after assembly should be able to catch this sort of fault before it gets shipped thousands of miles around the world.? You can even see the dimples in the solder paste where the transistor didn't stick. -- 73 -- rec -- ad5dz -- On Tue, Apr 1, 2025 at 3:51?PM Stan Dye via <standye=[email protected]> wrote:
|
Re: Debugging BS170-related issues
This is probably a stupid question with an obvious answer, but I don't want to screw it up....
?
Received replacement parts from Digikey. Removed old IC503 without incident (first time using ChipQuik).
?
The replacement 74ACT08SC-ND does not have the standard pin 1 dot I have come to expect on an IC. It does have a solid, white bar. Can I assume that is the pin 1 dot ?
?
Thanks and 73,
Steve, N2IC |
Re: ProgRock2 programming??
On 02/04/2025 13:54, Tom Smith via groups.io wrote:
I plugged it into the equipment and it seemed to work for a few minutes then stopped. I’m not sure why but I’ll set up another unit for another frequency and see if it does the same thing. It may be something in the equipment oscillator circuitry killing the PR2 (maybe a voltage issue)Tom, I think I'm right in saying there are no isolation capacitors on the Progrock's outputs. I hope you added one. Any voltage on the equipment's crystal socket could damage the 5351. 73 Alan G4ZFQ |
Re: ProgRock2 programming??
Hi Alan,
toggle quoted message
Show quoted text
Well, I thought I had the ProgRock2 programmed for the 6.6khz frequency, installed it with the two pins of a HC6 crystal base with a backside ground terminal soldered to the holder base. I plugged it into the equipment and it seemed to work for a few minutes then stopped. I’m not sure why but I’ll set up another unit for another frequency and see if it does the same thing. It may be something in the equipment oscillator circuitry killing the PR2 (maybe a voltage issue), so I’ll check that and see. It seems strange that the unit would work for a minute or two before dying. Thanks again for your help! Tom N5AMA On Mar 31, 2025, at 8:56?AM, Alan G4ZFQ via groups.io <alan4alan@...> wrote: |
Re: QMX + Backlight dimming
Hi All.? I have a similar goal-? screen is way too bright.? It does not seem to be the issue of pin 3 hitting the inductor on the power board.? So with r306, there are two solder pads on either side of the resistor.? Safe to assume that those pads are to receive a non-SMD resistor? Of course i have to yank the SMD one off the board, but then i just use the two pads for the non-SMD replacement, correct?
Thanks in advance
JD |
Re: Startup issue loading Firmware.
#firmware
#troubleshoot
#troubleshooting
#USB-C
I reached out to Jeff through the web interface for this group.?
?
He found a few issues with my mid band QMX, a couple of shorts (one of which took out my smps and cpu) and a few other minor issues (we both believe that my buttons might have gotten some Flux in them as they felt gummy to both of us).
?
Fortunately he had the tools to replace the cpu because I don't!? He also does great work.?
?
With that, I'll likely be a little bit captain obvious:
?
Make sure that the QMX is connected to the computer before even plugging in power to the unit.? Then turn it on.? This often resolved new units not connecting.?
?
Look very closely for possible solder shorts. I thought I did a good job of this, but the smps and cpu says differently.
?
Until you get the new firmware loaded and are ready to start testing the unit in full, use a current limiting power supply and set it to no more than 400 mA.?
? |
SWR and PWR does not show lcd
?
Hi, I've just finished my QMX+ rev.3 (firmware 1_00_027). Everything seems to be working correctly, except for the SWR and PWR does not show. They don't appear on the LCD, even though I have them enabled ON in the setup. The LCD display is working properly, showing the battery icon and clock, frequency, etc. Any advice would be welcome Thank you so much! 73 Miguel |
Re: Startup issue loading Firmware.
#firmware
#troubleshoot
#troubleshooting
#USB-C
Hi Bill,
Don't give up! You're almost there! As has been mentioned: make sure you have a good cable. Some are charge-only. That could stymie you right there. Make sure you're providing enough power. If it's not drawing excessive current, give it a little closer to the power you built it for. Building errors are easy to make and common, especially on the QMX mini. These errors often escape builders' notice, even on examination. There are lots of voices willing to share wisdom on this forum if you want to continue your building efforts and finish the job. If at some point you decide you've reached the limit of your own patience, you can find contact info for Jeff Moore W1NC on his QRZ (.com) page. He offers skilled repair in the U.S. for the QRP-Labs line of devices. Feel free to search the forums for ample testimony (including from myself) of his skill and generosity. It's a challenging build, and he provides a gracious back-stop to less-than-expert builders like myself. 73 de Todd W2TEF |
Re: Startup issue loading Firmware.
#firmware
#troubleshoot
#troubleshooting
#USB-C
Bill...
Have you watched this video ?
It worked for me on my Mac mini.
?
Rich, AD0SN |
Re: QMX Display Brightness
Hi all.? Yeah, my new QMX build, screen is way too bright and no contrast adjustment space (pot is turned fully counter-clockwise).? there is no contact with pin 3 and powerboard below.?
So, I will try this approach, but regarding R306 - are the two pads on either side of the SMD resistor meant to receive a non-SMD resistor?? So i can simply dig into my arduino boxes and pull out an appropriate resistor and tack it to those pads?
?
Thanks!
JD |
to navigate to use esc to dismiss