Hello Giuseppe,
Yes, an external 5 volt supply will work. I have 2 QLG-1's and a QLG-2 and use external power (not supplied by my QRP Labs equipment) on them all.

For the QLG-1 units I use a 7805 voltage regulator IC to step down externally supplied 12 volts to 5V.?

--Al
WD4AH

Hi Ben,

I like the power box.? I thought of doing this myself, though I would like to include the switch in the QDX case.??

On a clue from the QDX Linux ModemManager thread, I have added one more step that seems to avoid the power down and wait:? Use PuTTY to ensure the QDX is not in terminal mode.
? ? ?Startup PuTTY and connect to the QDX.?
? ? ?Exit out of terminal mode,
? ? ?close the window,
? ? ?and then start WSJT-X.?
The power down and wait I believe is resetting the terminal mode set by the first connection.? It probably takes about the same amount of time as using PuTTY.? Using PuTTY to ensure the QDX is NOT in terminal mode has been a more reliable process for me so far.

73
Evan
AC9TU

All,

I have found that the RF sweeps need to be connected to a good 50ohm resistive dummy load (shielded is better) to be repeatable (within accuracy limits).? Connecting to an antenna introduces received signals from the antenna which could be different each time you run the sweep.? Leaving it unconnected would cause issues with the lowpass filter that is ahead of the bandpass filter you are sweeping.

In my case, I had RF sweeps like Brent and on inspection of my L12 winding, I found that I had an extra turn in the first 19 turns of L12 which explains the lower peaks on the bandpass filter on my sweep.? Removing the turn moved all up, though 30 meters was still not centered.? The other bands were centered within reason.? My 20meters sweep did not seem to change much and is similar to Brent's before and after the turn removal of L12.

73
Evan
AC9TU

which freq. are you all using for the QCX WARC party ? I assume somewhere around 10.106 / 10.116 ?
73
Chris
M0AWN

Hi all,

NOTE that we are in winter time now ... so make sure that you are on the air in the correct time slot ;-)

For most of us in Europe, 1300, 1900 and 0300 UTC translates to 1400 , 2000 and 0400 CET?

73,
Luc ON7DQ

Hi Brent,

I have quite similar rf filter sweep graphs. I re did L12 and some other toroids risking to damage the pads but almost nothing changed. I was concerned especially about 20M as I have a similar weird graphic on that too. But last weekend I connected QDX to a tuned 20M antenna and did very successful qso's. So I think the rf filter sweep info is not that accurate. Do not do anything until this is cleared out as Alan suggests.
Take a look at QDX issues topic you can see my rf filter graphs and pskreporter screenshots that shows the QDX is working fine with even that wierd rf filter sweer graph.

/g/QRPLabs/topic/86953388#74545

Br.

On 15/11/2021 01:14, Brent WT4U wrote:

Here are my RF sweeps. Not pretty & not sure what's going on. I'm thinking to remove the first turn from

Brent

Do nothing until Hans comments.

The scale of each trace is different, look at the figures on the left. The 20m one in particular has a big range.
It seems to me these charts do not always work properly. I have seen different traces without making any changes to my QDX.

73 Alan G4ZFQ

Even better... one command that will stop and mask the service immediately, I just tested it (systemd 247 (247.3-3ubuntu3.6)).

systemctl mask --now ModemManager.service

About stopping ModemManager. The service can be stopped and disabled, but it can still be started again by other dependencies. If you mask the service it should never start again. You can always unmask the service to start using it again.

If you are never going to use 4G/LTE modems (USB sticks or built into laptops). This is the easier solution.

About masking and unmasking in the systemctl man page:

mask:
This will link these unit files to /dev/null, making it impossible
to start them. This is a stronger version of disable, since it
prohibits all kinds of activation of the unit, including enablement
and manual activation. Use this option with care.

unmask:
Unmask one or more unit files, as specified on the command line.
This will undo the effect of mask.

# systemctl disable --now ModemManager.service 
Removed /etc/systemd/system/multi-user.target.wants/ModemManager.service.
Removed /etc/systemd/system/dbus-org.freedesktop.ModemManager1.service.

# systemctl mask ModemManager.service 
Created symlink /etc/systemd/system/ModemManager.service → /dev/null.

On Mon, Nov 15, 2021 at 01:44 AM, syuji ota wrote:

However, when the Linux or Windows systems sends <CR> without user permission,

QDX goes into terminal application mode and USB audio is stops.

If so, can you change the command to enter terminal application mode?

This is interesting, but I was able to enter the QDX menu system while watching the spectrum with baudline, and the audio never stops when I pressed enter and entered the menu. Was also able to send CAT commands, the audio only changes when going between RX/TX.

I checked with the following commands:

serial console:
minicom -D /dev/serial/by-id/usb-QRP_Labs_QDX_Transceiver-if00 -c on

baudline:
parec --format=s16le --channels=1 --latency-msec=5 | ./baudline -stdin

Sorry, I meant to write George in the previous email, apologies it has been a long day!

Best regards, Peter.

Hi Twolane,

I will take this off your hands if you still have it, shipping is to Sanibel FL.

Thanks!

Best regards, Peter.

Hi all,

So far it’s been a fun project to build and have appreciated everyone’s tips and gotchas.?
And of course enjoyed Hans’ photos of his tech assistant.

Order# 50083

OS: RPi4 (Buster)

FW: was trying to install 1.01c from original shipped fw.

PWR: built for 12V (3:2), was using 9V battery as input for initial testing

PCB: Rev1
PCB placement: not in case, just sitting on table

Build deviations: removed SMD inductors as first item so PCB could sit flat before installing topside components. Build was straight forward except for the replacement inductors was messy.

?

Downloaded 1.01c to RPi and unzipped file. (119.5K)

Inserted 9V battery for pwr, LED blinks properly. Using Putty, successfully connected via USB from RPi4 into QDX on port /dev/ttyACM0 and was able to access the QDX.

First thing to do, update the FW to latest release before doing anything else.

In menu, selected “Update Firmware”, LED blinks slowly, brings up file manager similar to page 80 of manual v1.06. Dragged/dropped file 1.01c into the area window.

It brought up another window to show the transfer, but everything just stopped without transferring anything. LED went dark, and USB connection dropped. No magic smoke.

I’ve tried applying power multiple times, but no blinking LED, etc. and no USB comms. I checked both AMS1117 and they are putting out their required voltages. I don’t have fine diagnostic probes to check VDD on the processor or other SMD components without wreaking havoc.

Any thoughts what I did wrong and how to get it back to life?

thanks, 73,

.paul. VA3FUZ

firmware: 1.01c
OS: Ubuntu 20.04.3
xfrmr: 3:3 9v
power: 2S Li-ion ~8v
deviations:
1) went overboard with the magnet wire allowance and came up short on T2, so the B wire is from the scrap bin. No reason to expect it matters, except I had to scrape it the insulation.
2) no case. Still in my pcb vice

Here are my RF sweeps. Not pretty & not sure what's going on. I'm thinking to remove the first turn from L12 to shift the peaks up, but I don't think that will help the numbers or 20m.






–Brent WT4U

开云体育

Hans,

the issue with Linux arises because the QDX presents its serial interface as a modem, or in emulation-speak possessing the Abstract Control Model (hence the /dev/ttyACM0 designation, rather than the more frequent /dev/ttyUSB0). These days dial-up modems are a rarity, but wireless modems, such as for GSM, 3G &c. are in common use.

Rather than the drastic hack of disabling the Modem Manager, which may be needed to support other hardware, Ben's (PA2ST) suggestion (/g/QRPLabs/message/74652) of using a udev rule is a very sound & reliable solution.

Much other SDR kit requires one or more udev rules under Linux.

HTH, 73, Stay Safe,

Robin, G8DQX