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
|
QMX fldigi RTTY
So, I was trying out RTTY via fldigi on my QMX today. I tested receive yesterday, and it was fine. Today, when I try to transmit, I see some odd behavior, in that the QMX leaves transmit mode well before the message has completed sending, at least according to the fldigi screen. (I do get the full dash under the VFO "A", so it is transmitting, at least at first.). Should not be an SWR issue (on 20M, my SWR is quite low.)
The message is about 20 characters long. The QMX stops after about a second, but fldigi shows it taking longer, even with the waterfall set to "fast". That takes about 7 seconds. SOMETIMES the QMX is on for that entire period, especially if I change the waterfall to slow, then up to fast, but usually the QMX transmits for a second, sometimes a lot less than a second. RTTY is 45 baud, so about 4 cps or less, so the 7 seconds feels about right. I saw one message from January 2nd (this year?) indicating that a firmware issue had cropped up that prevented fldigi from working starting with release 1_00_007 (I am on 1_00_014, with a V2 PCB.) 73, JRJ W9IYN |
|
Excellent Repair Service, Jeff W1NC
When my QMX took a turn for the worse (magic smoke), I followed the suggestion many have made here. I sent it to Jeff W1NC. What a pleasant experience! In a short period of time I had my QMX back in working condition. Just as importantly his evaluation, findings and suggestions sent via multiple emails will make me a better builder. Thanks Jeff. 72 ?Peter/AA2VG
|
|
Re: #qmx Rev 3 - Low band - no output and no receive
#qmx
Inspect around the BNC connections.? A ground pad on the SMA footprint is very close to the BNC hot output.? It's very easy to have a solder blob there which shorts the output to ground.
-Steve K1RF ------ Original Message ------
From "AB9LM" <jshroomy@...>
Date 3/10/2024 10:45:52 AM
Subject [QRPLabs] #qmx Rev 3 - Low band - no output and no receive
|
|
Re: #qmx not powering up after firmware installation
#qmx
Hello Alex,
Please follow the links in this post: /g/QRPLabs/message/115761 Chris has provided a test process to check out each SMPS module. 73 Evan AC9TU |
|
Re: QDX-M on 60M?
Correction, that should have read QDX-M.
Allison got back to me and suggested using a multi-band QDX, mono band if I like. One just arrived a couple of weeks ago and has not been built yet, I have something to work with. Ron VE8RT On Sun, 10 Mar 2024 10:23:50 -0700 "Ron VE8RT" <ve8rt@...> wrote: I do not see it offered yet, the QMX-M for 60M. If I ordered the -- Ron VE8RT <ve8rt@...> |
|
Another thought on the input power situation is to use something like a 2 to 4 amp rectifier bridge or 4 separate diodes in a bridge.
This can provide 2 benefits: 1. Polarization protection.? Since the input is designed for AC, the polarity doesn't matter.? The + lead will always be + and the - lead will always be - 2. If you research it carefully, you can get the desired voltage drop across the diodes to give you the input voltage you require The other thought is that at higher current, the voltage drop is likely to increase (diode being non-linear).? Not sure if this benefit the finals. Looking forward to others thought on this option. ------- Robert Giuliano KB8RCO |
|
Introduction
Hello All,
I was remiss in not introducing myself earlier. I am a retired 77 year old geezer who is returning to ham radio after a hiatus of about 38 years. I was licensed in 1976 as VE4AAH and since then have held the calls VE1BWG and VE7FNS. I returned to Winnipeg, Manitoba in 1986 and am now VE4BWG. In my active years I developed a great fondness for QRP CW. Those interests still prevail but they will be joined by QRP digital modes. I am keen on FT8 and looking forward to getting on the air in that mode. I have already learned a great deal from reading the QRPLabs group posts and look forward to that continuing. I also look forward to possibly getting to know some of you and learning more about your interests and ham activities. This is an amazing group and I am glad that I have happened upon it.? Thank you for reading this and 73s Jim Williams VE4BWG |
|
Re: #qmx not powering up after firmware installation
#qmx
Hello Alex
toggle quoted message
Show quoted text
On Sun, Mar 10, 2024 at 06:05 PM, <alex_brasier@...> wrote: Is it alive or dead?I would say both. Does the fact that I see something in PuTTY mean that the firmware is successfully installedI would say yes. The SMPS for 3.3 V is working. The processor is working (without processor also no terminal session). But 5 V for much of the other hardware is not ok (also for backlight). Why? Hard to answer. about 200 mAA bit to much. You could remove the display and check via terminal. If its the same, the display should be ok. There could be an unwanted connection along the VCC rail anywhere. It could be a problem from a part feed by the VCC. You could check the PCB using a good magnifier. 73 Ludwig |
|
#qmx not powering up after firmware installation
#qmx
Hello all, I¡¯ve just finished building a low band QMX. I plugged in to a 7v supply, plugged the USB into my Windows 10 laptop, and (as is supposed to happen) nothing happened. I pressed the left rotary encoder and Windows recognised the USB device. A dialog came up, asking what to do with the USB, and (I think) I clicked ¡®open folder and view files¡¯. I had already downloaded and unzipped the firmware (1_00_017.QMX) and I dragged that into the QMX folder. The file seemed to copy, but then nothing else happened. Pressing the left rotary encoder does not turn it off, so I unplugged it. If I then turn it back 'on' by pressing the left rotary encoder then I see about 200 mA current, but the screen stays blank with no backlight. I tried connecting with PuTTY and I get the following:?
Supply voltage: 7.1 v 3V3 SMPS Frequency: 116666 Hz Status: SMPS Voltage: 3.35 V Duty max: 51% Duty cycle: 44% 5V SMPS Status: Error Voltage: 2.76 V Duty max: 77% Duty cycle: 77% Does the fact that I see something in PuTTY mean that the firmware is successfully installed, so can rule out failed firmware installation as the cause? I¡¯ve tried re-installing the firmware a few times, and tried v. 16, but always get the same result.?
If its not an issue with firmware installation then what¡¯s the likely cause? I¡¯ve re-checked the joints between the main board and the connector pins on the 5V SMPS with a DVM, and I¡¯ve checked all the other connector pins. I¡¯ve also checked for the short between Q103/Q104 though that doesn¡¯t seem to be a problem (it¡¯s a Rev3 board). Is it alive or dead? Any suggestions welcome!
Thanks, Alex / 2M0YMA ? |
|
Re: QCX and QCX For Sale
I am sorry but I need to correct the earlier post.? Both 40 Meter QCX's are the original and not the Plus.? One has the case and the other does not.? One is Rev. 1 and the other Rev. 3 with Rev. 1.000e.? Neither is working but fixable.? Offer still stands for $25 shipped in continental US for both. Sorry about the confusion.
73, Gary K4VIG |
|
Re: QMX (20-10, 1_00_017 fw) RIT dissapeared
Yes. No luck. I saw an earlier post where one person found bad solder flows on pins 92 and 93 of the MPU and reflowed them and it worked. I'm going to check to see if that is the case with mine. 73 Don WA2SWX? On Sun, Mar 10, 2024, 7:31?AM Eric <emfell@...> wrote: Have you tried reflashing the firmware to see if it is just a software glitch? |
|
Re: #qmx Rev 3 - Low band - no output and no receive
#qmx
Everyone,
I couldn't be more grateful for the help. It actually turned out to be a "semi-intentional short" at the BNC. There were a couple holes on the PCB at the BNC that were trace connected. I didn't realize this. I had soldered them to the ground pads nearby and didn't think much of it. Just thought it was part of the ground connection.? I now have audio on all bands and it seems an absolute miracle that I didn't blow the bs170's. I'm seeing 4-5w out on all bands. Sometimes we just need one little spark of information to approach our troubleshooting from a different angle. Again, please accept my warmest thanks to all of you! Very best - James Shrum AB9LM |
|
Re: #qmx Rev 3 - Low band - no output and no receive
#qmx
James.
Yes, that is as expected. Where do you lose the receiving signal when using the antenna to trace from L12 to the BNC? 73 Evan AC9TU |
|
Re: #qmx Rev 3 - Low band - no output and no receive
#qmx
On Sun, Mar 10, 2024 at 03:45 PM, AB9LM wrote:
19mA? ?- Powered offwrong, maybe some ?A or so. Please remove the power plug from the QMX and check the current. Maybe the current is going a different way. If 19 mA are flowing through the QMX in off state, there is a fault inside. Fix this first! 120mA - RXThis is a little bit to much. Please check the HW diagnostic using the terminal. Check the work of the SMPS. 1.3A? ? ?- TX @ 80mand I'm seeing zero output at the BNC into a dummy loadDangerous! A short in the area between the LPF and the BNC or inside the BNC (or inside the cable to the dummy)? SWR sweep showed straight 10 on all bands,Short between T507 and BNC (or in the cable) or in T507? If you have a short in T507 a bypass doesn't remove the fault. Further tests of the TX in the current state endanger the Hardware. For further tests of the TX I recommend strongly to reduce the voltage to not more than 8 V. There is danger of destroying the PA transistors (and more). 73, Ludwig |
|
Re: #qmx Rev 3 - Low band - no output and no receive
#qmx
James, Another way to get noTX? & no RX is if C526 has been damaged or is missing a solder joint. JZ KJ4A On Sun, Mar 10, 2024 at 11:16?AM AB9LM <jshroomy@...> wrote: Evan,? |
cube1us
to navigate to use esc to dismiss