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QMX digimodes you have tested

 

Is it possible to have here the list of digimodes you've tested successfully with your QMX and with which piece of software ?

On my side, for now :

- JS8call
- FT8 with WSJT-X
- WSPR with WSJT-X

TNX
QMX settings for Varac

 

Hello OMs,

I've received my QMX for 60-15m last week and finished assembled it.

Very nice rig, working properly with TX output beetween 2 - 4W depending the choosen band.

Digi is also OK with WSJT-X and JS8Call (TS-480 settings).

But I can't make it to connect with Varac even though I'm using I guess the same parameters. I've no PTT check and also no frequency adjustment.

Anyway the soundcard is OK with VaraHF modem, well recognized.

So my questions are :
- Do you have settings for Varac ?
- Is QMX suitable for use with Varac (I'm not familiar with modes you can operate with QMX, as I've red that it's not possible to do PSK31 for example).

Thank you !!
Re: New QDX not talking to my raspberry pi #troubleshooting #wsjt-x #raspberry-pi #qdx #transmitpower

 

Hi,

I have been having the same symptoms with a new setup on a Raspberry pi 3b.

I have just set the sound level to 100% (using amixer cset in terminal, See link below) and suddenly I'm transmitting and getting contacts!

Many thanks for the tip!

David
Re: QMX Preset Problem

 

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Hello Ron,
?
Yes you are correct they don't.
?
I tried this by just changing Band and switching aerials to match, it seemed OK, but looking on the scope with a D/L it doesn't switch. Sorry for the confusion
?
73
?
Ian G4GIR
?

----- Original Message -----
From: Ronald Taylor via groups.io <wa7gil@...>
Reply-To: <[email protected]>
Sent: 01/07/2024 21:58:34
Subject: Re: [QRPLabs] QMX Preset Problem
Just tried that Ian and the filters did not switch.?

Ron

On Mon, Jul 1, 2024 at 13:46 Ian G4GIR via <g4gir.shack=[email protected]> wrote:
What does work is changing band by pressing and holding then rotating the ?TUNE button till getting to the MHZ digits,?then selecting the Band, the correct LPF/BPF get selected. Except of course you can't select 160m using that method also when switching off and on again it doesn't remember the band.
?
?Whilst on the subject of Band Selection, does anyone find it a PITA to QSY from 10m to 12m etc. All those double presses!! I figured the Presets would help solve this but with the BPF/LPF selection anomaly ?there is no choice. Could the band selection method be changed? In fact the above method is quite quick but could be easier if you didn't have to hold the TUNE knob in. Maybe 3 quick presses?to select the MHz digits??
?
73
?
Ian G4GIR
----- Original Message -----
From: Ronald Taylor via <wa7gil@...>
Reply-To: <[email protected]>
Sent: 01/07/2024 19:37:35
Subject: Re: [QRPLabs] QMX Preset Problem
The other side of the coin is even worse. If you select the 20 meter band by double clicking the volume knob, then use the preset to select 80 meters, the filters stay at 20 meters and all the harmonics of 3.5 MHz show up in the transmitter output up to the cutoff frequency of the selected filter. It's probably best not to use presets except for frequency changes within the band selected by the volume knob until this is corrected.... Ron

Re: QMX (frequency) presets not working properly / maybe "dangerous"

 

Hi,
the measured increased output power could be a result of an improper LPF selected.
In such case the output could consist of a strong third harmonic component.
3.5 x 3 = 10.5
5 x 3 = 15
7 x 3 = 21
--
73 Bojan S53DZ
Re: QMX (frequency) presets not working properly / maybe "dangerous"

 

I've had a really odd situation with presets.

Some of mine, when recalled, present similar to as described here.?

My 80m & 40m though often Txs fine but at (relatively) insane power. 8-10w out and this is verified on an external power meter and PuTTY.

I too have spotted using them.?
Re: Help with QMX 60-15m 40M issue with receive

 

Ok, so given both 60 and 40 share the same rx filter then I wonder if the fault is inducing noise from elsewhere in the radio due to a fault.
This could be a solder bridge, dry joint or any of the usual faults we put in when building a radio : )

The LPF forms part of the RX chain, it would be worth checking that, or even swapping LPF's between 30 and 60/40 to see if the fault moves / changes.

Warren.
Re: Help with QMX 60-15m 40M issue with receive

 

Yes 60m has similar noise, my antenna is for 40m so too small for 60m.??

The noise is high on 40m but not 30m.? Signals on 40m are very weak.? I have other qrp rigs and at nite there are many signals on 40m but I can usually only hear 1 or 2 on 40m on the QMX.

I would greatly appreciate assistance to find the issue.? Thanks!
Re: Help with QMX 60-15m 40M issue with receive

 

Hi Bruce,
From memory my Sweeps look similar to yours for 40m.
You speak about the loud noise on 40m when compared to other bands, whilst you may not use 60m does it have the same noise on rx?
Given the sweep look OK, maybe you have a different issue that is allowing "noise" from elsewhere in the radio to bleed into the RX chain.

73,
Warren.
Re: QMX+ Issues

 

Hi Ed
If I understand correctly, the issue might be the way the button cell is inserted in the socket. The small metal fingers on the left hand side of the button battery socket must be on TOP of the button cell?+ side. To ensure this happens when inserting the cell, tip the cell so the edge of the cell is down UNDER those small metal fingers, then snap the cell down on top of the metal fingers on the right side of the socket. I had trouble fitting the cell in the socket until I figured out the method.?
Hope this helps.
72 de Dave VE7AHT
Re: QMX rev 2 no power out

 

I have a scope, but I'm not sure what I'm doing with it. I did measure some voltages in RX and TX mode of that mosfet. I have attached a photo showing those.
Re: Help with QMX 60-15m 40M issue with receive

 

Can anyone confirm, does my RF sweep above confirm the caps c40x and the torroid L401b are good and working?? Seems to me from reading if either of those were wrong for 40m I would notice it on a bad 40m RF sweep?
QMX+ Issues

Ed Pflueger-AB4IQ
 

To begin with the QMX+ was working great until I couldn't get the battery voltage down underneath the GPS.? So, I started looking for the missing voltage and got my multimeter probe across a couple of pins on the 3.3 board and the lights went out.? So I ordered another board and put it in without success.? I have another board so I'm afraid to stick it in and smoke it.? I do have spares of the boards.? Nothing like having spares.? In the meantime I was checking for the 2032 battery voltage across the holder and there were none.? After further inspection the batter I bought had a ridge on the + side so the upper contact was not making.? I found another one without the ridge and now have battery voltage under the GPS so that issue is fixed but now I need to chase down the problem I created.? Any ideas?

Ed.. AB4IQ
Re: QMX (frequency) presets not working properly / maybe "dangerous"

 

I agree. Stopped using Presets. Has Hans posted on this topic??
QDX has gone single band TX

 

Was 20-80 tx and rx - and has been a solid unit for months.

Now 20-80 Receive
80m only transmit.

Terminal software only shows 80m - so it thinks it single band.

Fresh firmware, 1.10, and no other issues.

Anyone seen this before...any tips?

Tom
Re: QMX+ Power Increasing Question

 

Bi Ludwig
Thank you for the reply.? The probe is a PP-150 which came with the oscilloscope.? I have used it for a few years.
Its bandwidth (@10:1) is 100 MHz.? The probe compensation allows the square wave calibrator to show a good squarewave with no ringing.
The input impedance is 10Mohm/18.5pF.
It is the output voltages from the ExOR gates and the AND gates that concerns me as the lower the voltage output, the lower the RF output from the BS170's.? The measured RF output is within a few 10ths of a Watt as shown on the puTTY Terminal.? Both measurements decrease at the same rate to 0 @ 6m.
Any help you can give would be appreciated.
Regards
Greg
Re: Key clicks when AGC is active #qmx

 

My statements above only seem to be true on 40m, so I opened a new thread for this.?

I did not experience key click issues with recommended settings on 15m or 20m.? Please see my other thread and assist if you can.
Re: New QDX not talking to my raspberry pi #troubleshooting #wsjt-x #raspberry-pi #qdx #transmitpower

 

Did you ch3ck the alsamixer settings on it?
Mark N5OBC

On Mon, Jul 1, 2024, 3:04?PM jamesdrenda via <jamesdrenda=[email protected]> wrote:
Hi - so just completed my second QDX (rev 6 high band this time), and tested it and it works fine with my Windows machine on WSJT-X and with my android phone running FT8CN. When I hooked up to my raspberry pi 3b, it is able to run the cat, and receive and decode. However, when I go to transmit, I only get 0.5 watts at most from the rig.

Normally I would chalk this up to the pi, but, the pi had been able to run my old QDX, and currently runs my QMX (low band) just fine. I have tried fiddling with the settings (changing from the TS440 to TS480, and also changing the new QDX to VOX). I am out of ideas, is there something I am missing?

73,

Jim KE4MKG

Re: QMX+ and battery

 

Nice work on the cable


On Mon, Jul 1, 2024, 6:09?PM Kees T via <windy10605=[email protected]> wrote:
Doug,

Made it up from 2 right angle 2.1mm pin barrel pigtails.

73 Kees K5BCQ

Re: QMX+ and battery

 

Doug,

Made it up from 2 right angle 2.1mm pin barrel pigtails.

73 Kees K5BCQ
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