Re: QCX-mini constant transmit

Dave Burroughs

Well Julian, 

The plot thickens.   I got back to things and when I turned on the QCX-mini, it did the transmit thing for about 30 seconds.  I checked IC3 and it was slightly warm but so were the three BS170's and Q6 so difficult to say if IC3 was getting warm on its own or from the PA MOSFET's.  

I decided to pull the audio and paddle jacks one at a time.  As I removed each one, I inspected for solder bridges but as it turns out, the solder had not capillarated to the top side of the board through the solder holes.  I checked the operation of each 3.5mm jack and they both rang out the same.  All of my work was performed on a silicone soldering mat and I did not find any tiny pieces of wire strand or solder on the mat.  Plugging in the radio without the display or control boards did not exhibit the constant transmit problem.  I reinstalled both 3.5mm jacks and all seemed well at the time.  So, I reassembled the radio and it seemed fine.  I left the radio turned on for the evening and transmitted into a dummy load from time to time from a memory.  Three hours later, all was going well, so I put it back in the enclosure making sure nothing on the bottom side of the board could touch the case.  I even put Kapton tape on the bottom cover.  Checking the radio before I went to bed, all was fine and I listened to the W1AW CW bulletin on 14.057.5.  

Here is where things went awry.  When I turned the mini on last night, the S-meter was jumping all over the place and it sounded like constant lightning static in the headphones.  I tapped every component on the board to no avail.  I tried some freeze spray and could not find anything.  After 10 or so minutes, the static in the headphones started to settle down until it was completely gone.  The mini was now working as it should although I don't believe the alignment process was able to find dips in IQ Bal, Low and High settings. I hear faint voices on receive below the CW signals.  The BPF peaks between 7 and 8.   

This morning, I turned on the radio again to be greeted with the heavy static crashing sound on the headphones and the S-meter jumping full scale.  After being powered on for about 10 mins, the static crashing settled down and the rig is working (with the voices).  I called CQ a few times and had three RBN hits from Texas, Alberta and Arizona.

The head scratching continues.  
Dave - VA3CP

Re: QCX challenge #qcx_challenge #qsoparty

Zdenek OK2BQN

Hello Martin,
I also have a QCX + 5W at 80m. We can try next time.

Re: Wide filter on QCX?


Thanks Johan.  I was thinking it was not as simple as just changing the menu frequencies and readjusting.  I have 2 QCX's I've widened the filter on and while they do appear to
have a flatter response, imaging on strong signals is apparent.  I did look at the ARRL article and that is the way to do it.  Much more complicated though.  
Another thing I've noticed is both widened QCX's exhibit a spur at 1400 Hz that was not there  with the stock QCX filter.  It appears to be audio not rf as it will not move with tuning.
It's not avbig issue but I'd like to clean it up.

I also have  a QRPLabs RX with Polyphase network.  I'll take a look at that.  It may be a better solution.



On Tue, Aug 31, 2021 at 5:13 PM Johan Bodin <jbodin@...> wrote:
Hi Bob

There is no problem with widening the filter built around IC8/IC9 (on
QCX mini schematic) but the precision of the 90 degree I/Q phase shifter
(IC6/IC7) is too narrow to give a good opposite sideband suppression
over the entire SSB bandwidth. Widening the bandpass filter will work,
but, expect bad opposite sideband rejection outside the CW tone
passband. It will behave just like a simple direct conversion receiver
with (almost) equally strong response either side of zero beat except
around the CW center frequency.

At least 3+3 stages of all-pass filters are needed for good opposite
sideband suppression over a voice bandwidth. See for example

Jim Tonne (forgot his callsign...) has written a nice program for
designing 90 degree I/Q phase shifters. Look for the program "QuadNet"


WA1EDJ wrote:
> After reading a few threads on widening the CW filter on the QCX, I've
> come up with some R and C values to try for an SSB bandwidth.
> What I'm not sure of is what frequencies the alignment menu items:  IQ
> Balance Freq, Phase Adjust LO and Phase Adjust HI should be set to for
> SSB bandwidth?
> I know IQ Balance Freq was 700 Hz for the original CW QCX.  So for my
> wider filter, I'd like center to be 1500 Hz, so set IQ Bal Freq
> accordingly?
> Original Phase Adj LO was 600 Hz.  What would be appropriate for the
> wider SSB filter?  Likewise for the Phase Adj HI which was 800 Hz.
> I realize the QCX was not intended to be for SSB reception.  I'm just
> trying to tune the best I can for a wider filter.
> TNX!
> Bob

Re: LCD blank

Alan G4ZFQ

You are describing it displaying ONE row of blanks. Only both when the control is excessively advanced.
Here it says that the processor is not talking to the display.
Check out the processor.

73 Alan G4ZFQ

Re: QLG3-enclosure, a work in progress #gps #enclosure

Roelof Bakker

Hello Dave,

I am using a PCB design program (Sprint-Layout 6.0) to design a panel and print it on plain paper. For protection the paper panel is laminated using a 125 um pouche.

For mounting it on the case I use thin double sided tape.
This works very well and will surfive an excidental touch with the solder iron!

Roelof, pa0rdt
Roelof Bakker, pa0rdt

Re: LCD blank

Wayne Robertson

Thank you; clear now.

So, the gnds and voltages check out yet the LCD is still blank or shows 1 or 2 rows of rectangles, depending on contrast setting of R47.  Anyone have any other ideas, or should I reach out to Hans?

Thanks Julian and Mont.

73, Wayne  

Re: QCX 50w amp receive problem


Check that all the connections on C1, C16, D3, D5 and associated components are good - reflow the solder connections. Using a DVM check the PCB traces between those components (I had problem with a broken trace on my 50W build).

With the unit powered up and on receive, Q5 drain (connected to R12) should be near supply voltage and junction on D3 and D5 should be near ground (zero V). At the same time, the anodes of D3 and D5 should read about plus 0.6 Volts.  If these conditions, aren't met, you have a problem somewhere in that circuit area.
Peter Lee

Re: Which SuperCap for QLG2-SE #gps

Roger G4IUP

Hi Mont,
Was wondering the same thing myself. I also find 0.47 hard to find at a reasonable cost. Lets hope someone can help us !
73 Roger G4IUP.

Re: QCX-Mini doesn't Auto-set time with GPS #gps #qcx #troubleshoot


Well, the good news is it seems the 1 pulse per second is working as  you are able to calibrate the crystal oscillators (8.11 and 8.12).  Those serial data traces look a tad noisy, but as you say, that could be due to things like earth loops on the scope input.  But I would concentrate on looking at the serial data - does it look clean directly on the output of the GPS, for example?  You may have a grounding issue with your lead or perhaps the serial data is not the full 5 volt swing?

Check that a good 5V swing of serial data is available on pin 19 of the microcontroller (IC2).  If the keying paddle works OK it would pretty much rule out any poor connections from the keying jack to the controller.

Interestingn one, this.  Hope you find out what's going on!
Peter Lee

Re: QLG3-enclosure, a work in progress #gps #enclosure

David Wilcox K8WPE

I still don’t get it.  Do you glue the card stock to another thicker piece of cardboard?  The whole panel is cardboard?  If so how do you get it strong enough to hold meters, speaker, etc? Or just crude holes cut into pc board and the card stock glued on to make it look nice?

Dave K8WPE

David J. Wilcox’s iPad

On Aug 31, 2021, at 1:37 PM, jjpurdum via <jjpurdum@...> wrote:

They are all card stock, but Al did them, not me.

Jack, W8TEE

On Tuesday, August 31, 2021, 12:18:44 PM EDT, Harry Latterman via <harrylatterman@...> wrote:

If those are all card stock from panels... I am impressed...very impressed..

Harry K7ZOV

On Tuesday, August 31, 2021, 08:50:07 AM MST, jjpurdum via <jjpurdum@...> wrote:

On Tuesday, August 31, 2021, 11:39:34 AM EDT, Al Holt <grovekid2@...> wrote:

On Tue, Aug 31, 2021 at 09:45 AM, jjpurdum wrote:
Now we print a cardstock template and do the LCD/display cutout with an X-Acto knife (make it just a smidgen smaller than the display).
Not sure I understand what you've written. Is the entire top cover cardstock? Yes. All of these use the same technique:

<All Projects - Small.jpg>

A small amount of glue holds it in place
Is the glue holding the LCD/display in place? On this particular one, yes. On most, we use countersunk flat head screws.

and a thin coat of clear Krylon protects it.
I can picture that for protecting the card stock, but are you also spraying the display? No. We cover it with masking tape during the spray.

I may be totally off the mark on understanding the technique. Thanks!

<All Projects - Small.jpg>

Re: Question about customizing the QLG2/QLG2-SE serial data #clock #gps

Alan G4ZFQ

On 01/09/2021 02:36, Mont Pierce KM6WT wrote:

I got the Clock running great now with the QLG2-SE.  Sent the following command:
That's some progress!
NaviTrack has that command built in but most of the other commands need it to be used like a terminal program.
It's far from being a good program but it does show Glonass and Beidou.
On my setups I am asked when I start the program which, I suppose, is the same as running as Administrator.
I have seen no way of saving settings. I do not think a supercap will help, it loses baud rate settings if it is powered on and another seemingly unrelated command is sent.

73 Alan G4ZFQ

Re: Question about customizing the QLG2/QLG2-SE serial data #clock #gps

Mont Pierce KM6WT

On Tue, Aug 31, 2021 at 06:24 PM, Mont Pierce KM6WT wrote:
NaviTrack is mentioned on the QRP-Labs G2 webpage near the bottom:

Note here is the Navitrack software for the Ebyte module. The Navitrack software may be used to check it, see NMEA, satellites, send commands including the update command.

I downloaded and tried it, but the zip file seems to be incomplete.  I get an error pop-up stating:  "Call to DllRegisterServer failed".  It might be a missing file or a Win 10 issue...
Ok, I found my issue causing this failure...

On Win 10, you have to right click on the program name, and select "Run as Administrator".

So I now have NaviTrack talking to my QLG2-SE.  Now, I just need to investigate what it can do, as far as setting/saving custom configurations, like Baudrate, and, setting which satellites to look for.


QCX-Mini doesn't Auto-set time with GPS #gps #qcx #troubleshoot

David (W5CWT)

I am trying to set the clock on the QCX-mini with the QLG1 gps unit. The GPS unit seems to work (all LEDS operate as expected) but the radio never sets the clock or the grid square. Calibration menu items 8.11 and 8.12 both seem to work without issue. 

When I scope the output of the QLG1 I see the 1pps on the tip and what appears to be serial data on the rig BUT it is not very clean. I am a noob with a scope, so I could very be at fault for the traces. I can't seem to get a reliable (or valid) decode with the RS232 decode function on the scope.

I've added photos. Any suggestions?

David W5CWT

QCX 50w amp receive problem


Hello to all.

I recently completed assembly of the QRP-LABS 50w amp for 20 meters.  This amp is for my QCX mini.  I used the mini in several qsos and the radio is performing perfectly.

After completing assembly, I performed the adjustment procedure.  The amp was pulling 74.5ma there.  I measured 19w output at about 13v transmitting into a dummy load.

I hooked up the amp to my antenna and called CQ.  I checked the reverse beacon network and my signal was received by several stations so it looks like the amp worked correctly.

The only problem I am having is the amp is not passing back any signal for receive to the QCX.  I've double-checked the orientation of all diodes.  All of those look correct.  In addition, I've inspected all solder joints and I don't see anything cold or bridged.

Can anyone help me out here?

Tom Dostal

Re: QCX challenge #qcx_challenge #qsoparty


Hi Luc, I noticed my error (66) immediately after submitting. Unfortunatly, the corrections on the site take some time - I resubmitted (6) just after the original fault. 

Apologies, Jens DG2FDD 

Re: U3S not calibrating????


Hello everyone, I use the U3S from 6 bands, but in transmission only 1. at this moment the beacon works with U3S single band because I am waiting for the spare bs170 mosfets, however every single U3S has its own calibration.  I am fine using on cal step time 3-220.  That's fine. 73 iu8eun

Il mer 1 set 2021, 00:46 <jrc198820@...> ha scritto:
Thanks. That helped me understand a little better.

I think it's sorted out now.
I did a reset and started from scratch.

This would be a good explanation to put in the file section.


Re: U3S not calibrating????


Il mar 31 ago 2021, 10:31 iu8eun Giuseppe Coppoletta <iw8rsb@...> ha scritto:
Hi James, try to increase Cal step time to 3 and 220, I send back some of my configuration photos on the U3S beacon on 14.097100.  greetings from iu8eun Giuseppe

Il mar 31 ago 2021, 10:17 M0RON <eustace.andy@...> ha scritto:
What do you have the calibration parameter set to? How many tx slots? Did it ever calibrate? 

The universe is made up of Protons, Neutrons, Electrons but contains only one M0RON.

Re: LCD blank


I'm saying that pin 1 of the connector on the circuit board is at 180 degrees from what the picture of the connector on the schematic suggests that it would be.

The schematic suggests that pin 1 is the "Northwest" position on the circuit board. It isn't: it's in the "Southeast" position on the circuit board, looking at the circuit board in the same orientation as if you were operating it, which is with the BNC on the top of the board, sticking out to the right..

So you cannot assume the orientation of the connector on the circuit board matches the orientation in the schematic.

I hope that's clearer.
Julian, N4JO.

Re: Question about customizing the QLG2/QLG2-SE serial data #clock #gps

Mont Pierce KM6WT

On Tue, Aug 31, 2021 at 10:56 AM, Mont Pierce KM6WT wrote:
The clock works really well with the QLG1 gps unit.  However, seems to have a few issues when I try using the QLG2-SE with it.
  • Many times a minute, several Heartbeats are skipped..
  • The Seconds display is erratic, sometimes jumping forward and back, and sometimes advances by 2 seconds.
I got the Clock running great now with the QLG2-SE.  Sent the following command: 


From page 5 of the GK9501 document in the Group Files section (click here)

9. Command: 115
Set enable search mode
Arg1: "1", GPS on
      "0", GPS off
Arg2: "1", Glonass on
      "0", Glonass off
Arg3: "1", Beidou on
      "0", Beidou off
Arg4: "1", Galieo on
      "0", Galileo off
  Example:  $PGKC115,1,0,0,0*2B<CR><LF>

It works great BUT...  on power cycle, the setting reverts back to the default.   :(
Same problem Alan mentions when changing the baud rate.  It doesn't save it, and reverts back to 9600 on power cycle.


Re: Question about customizing the QLG2/QLG2-SE serial data #clock #gps

Mont Pierce KM6WT

On Tue, Aug 31, 2021 at 11:37 AM, Alan G4ZFQ wrote:
I have some notes here
Thanks for the link, interesting reading.

NaviTrack is the utility to command the module.
NaviTrack is mentioned on the QRP-Labs G2 webpage near the bottom:

Note here is the Navitrack software for the Ebyte module. The Navitrack software may be used to check it, see NMEA, satellites, send commands including the update command.

I downloaded and tried it, but the zip file seems to be incomplete.  I get an error pop-up stating:  "Call to DllRegisterServer failed".  It might be a missing file or a Win 10 issue...

In spite of the error pop-up, NaviTrack opens it's dialog window, but then crashes when I try to connect to the serial port.

Maybe Hans will comment regarding the clock, otherwise it looks like experiments.
I did already mention to Hans the issues I'm having, and, he's got it on his looonnnngggg list of things to do.
Anyways, I thought I try a few things in the meantime.  :)

On Tue, Aug 31, 2021 at 11:41 AM, Alan G4ZFQ wrote:
Yes, but my tests seem to indicate the QLG2 will not remember a different baud rate, reverting to 9600.
Maybe I did something wrong and you will find otherwise although I tried a few times.
Yes, I'm seeing the same thing.  I wonder if this is one of the parameters that would be backed up if I had the SuperCap installed ?
Either that, or software like the NaviTrack may be needed to store the config settings into it's internal flash?

Mont - km6wt

16981 - 17000 of 87031