Input impedance of the Tayloe Mixer on the QDX-M for 630M?
Just going to mess with the RX filtering on the QDX-M for 630M.
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Does anyone know the measured input impedance there?? It has lots of variables if you calculate and I don't want to re-invent the wheel.
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I have an assortment of MCL RF Transformers and will probably use something like the 8:1 ADT8-1T+ or lesser step-up.
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Thanks,? N0UU
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Re: Power Source for 50 Watt Amp for QCX Series
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Re: Updated QMX Condensed Menu plus Excerpts from the QMX Operating Manual with Comments
QMX Quick Menu Reference - Firmware 1.00.027
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Major update now that have a QMX radio in hand and am able go through the Menu system myself.
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If you notice something that needs changed let me know.
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Is there still a hold up on QMX+ kits?? I have not progressed from Complete to shipped on 10 days.
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Chris / W2BPL
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Re: QMX+ No transmit or receive
Hello all! I finally had a chance to get a few screenshots of my diagnostics . I picked one band to sample, the?80m band. I am having the same problem on all bands. I hope this may shed some light on my problem. In my opinion, the LPF screenshot looks okay but the others are of some?concern. Can anyone tell me what they think of these? Thanks!
Thank you to everyone in the group!! And hope you all have a merry christmas!! I just realized that farther back in this thread, I?said that I would submit audio and RF sweeps and I still have not done it yet. Been very busy lately. I have reviewed this thread several times away from the shack and in solitude, lol when i get it, to absorb all the info i have been given. What I documented is this.... Low pass filter sweeps were good on the lower to mid HF bands (160m thru 20m), and not so good on higher bands like 6m Audio sweeps all bands -100db,**** RF sweeps all bands 90 to 120 db below with no detectable center frequency?on any bands, Image sweep , no bands above -90dbSWR sweep very chaotic due possibly to the low power output. As I previously promised, I will try to submit some actual?screen shots of my sweeps. Just received my new QMX mini kit today from Hans and?I want to wait to figure?out?my problem with?the?QMX+ before I?start that project. I cannot handle multiple?unfinished projects around the house. Again, I want to say thanks, Merry Christmas and a Happy new year!! Will be back again with the screenshots.
73s Joel MacNeill VY2KW
On Mon, Dec 16, 2024 at 11:47 AM, Chris wrote:
The gate of Q507 should be high (+12V) in receive
Yes and no. In RX mode the voltage to the PA (BS170) is switched on again to reduce the D-S capacity of the BS170. There is a parameter in the Advanced config (see operations manual).
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73 Ludwig
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Re: QMX and SDR++ on GNU/Linux
Did you power-cycle the qmx after you connected the USB cable to the computer?? QMX does not initialize its internal USB support unless the connection is present at startup.
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Re: QMX and SDR++ on GNU/Linux
If you're familiar with the Python programming language, you might try tinkering with some
programs I wrote a couple of years ago for the QDX.? I haven't built my QMX+ yet, so I don't
know for a fact that the software will work with the QMX.? In any case, it consists of two
Python scripts, one which just directly streams the QDX's internal SDR to Linux and the
other which provides a UI to set the frequency, sideband, and volume.? It's available
at .
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I'd be interested to know if it works with the QMX.
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Cheers -
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Bruce K1FFX
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Re: QMX and SDR++ on GNU/Linux
So what I did I downloaded nightly build of SDR++, enabled IQ in the QMX submenu of Digi interface (but enabling disabling didnt make any difference) and selected Audio source in the SDR++. However for me there is only ALSA and PulseAudio option to choose from, I use neither of these (it's a PipeWire system) and on the YouTube this showed up for someone who got it working properly as Digital Sound Interface 2 - QMX, that's not the case for me. Is there any way to check that it's SDR++ fault and not QMX fault? Also I would really love to see this working with some other SDR software like GQRX which has less bugs. Help apprechiated.
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Re: QMX and FLDigi - MFSK modes
(repeating with corrected link):
Nico, RTTY works fine from fldigi once you set it up to what the QMX needs.
All of the other fldigi modes that use a single frequency at a time (MFSK, Contestia, etc) also work fine, as described in earlier messages in this thread.? The modes that don't work are any of the phase-shifting modes (psk, etc.), and they won't work until we get an SSB upgrade to QMX.
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See the fldigi setup info I posted in these two messages (both are required):
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Stan KC7XE
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Re: Windows fldigi and QMX+
#fldigi
(trying again with a proper window snapshot)
One more important setting I forgot to mention in fldigi:
You need to turn off "Shaped Tx" - this conflicts with the QMX internal shaping routines, and causes QMX to drop transmit.
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Re: Release of version 1.2 of ABS solution for QMX+ (Automatic internal antenna tuner, internal battery and internal speaker with audio amp)
#ABS
#ATU
#PSU
#QMXplus
Few thoughts about group buy.
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Cal and Stan probably are busy with a holiday season plus receiving, packaging and sending out kits. Please give them few more days to respond and feel free sending an email.
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At the same time, I want to remind that this is an open source project. All PCB fabrication files, BOM, firmware and assembly documentation has been published on GitHub. Anyone can use those to order and build the solution.
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The minimum PCB order size is 5 from JLCPCB - this is where the scaling factor and an advantage of a group buy comes to the picture. Theoretically, if group of 5 is there anyone can organize a group buy. Although - the bigger the group the lower the ROI per each individual PCB set.
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73,
Sardar (AC8L, 4K6SA, VA3DUA).
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Re: Enhance QMX+ To 10W SSB QRP
Please, let's keep to the subject ?
On Thu, Dec 26, 2024, 12:04 PM Nico Smith via <nicosmith873= [email protected]> wrote: We can hope! ?
Maybe it will be a New Years release...
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John AE5X
-- Dale Hardin
KS4NS
Elberta, AL
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Re: QMX and SDR++ on GNU/Linux
If anyone has a good guide on how to set it up with SDR++ that would be awesome
I can't fully answer your question, since I don't currently have a linux box set up for use with my QMX - but regarding the last part of your question on the I/Q mode:? The QMX gives (and uses internally) true I/Q data.? I have used it with two different Windows SDR apps, and the audio produced sounds great in SSB, Digital, and CW.? So there must be some issue with your particular setup if you are getting terrible audio.
Stan KC7XE
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Re: QMX and SDR++ on GNU/Linux
I can't fully answer your question, since I don't currently have a linux box set up for use with my QMX - but regarding the last part of your question on the I/Q mode:? The QMX gives (and uses internally) true I/Q data.? I have used it with two different Windows SDR apps, and the audio produced sounds great in SSB, Digital, and CW.? So there must be some issue with your particular setup if you are getting terrible audio.
Stan KC7XE
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Ludwig,
thank you for the tip. I will make the test tomorrow. But even if it was the 1804 I will not be able to repare it.?
We will see
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73 de Rico, DG5BQ
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Re: Enhance QMX+ To 10W SSB QRP
Maybe it will be a New Years release...
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John AE5X
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qcxHi Roland,
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By "open," I mean very large resistance between the leads, as in an open circuit.
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It would look like the drain of Q4 is not connected because the center lead is cut off.? The drain is the tab at the top of the device, as in the datasheet:
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Measure the resistance across L1, L2, L9, and L10 with the power off and disconnected.? All should be very low, almost zero ohms.? I believe that one or more of these inductors is an open circuit.? If not, we must check that the diodes switch on and off when receiving and transmitting.? Measure the voltage on the cathode (banded side) of the diodes.? It should be high when receiving and low when transmitting.? Run this test with the QCX in practice mode or the QCX output connected to a dummy load and the input to the amp connected to a separate dummy load.? In total, not using the practice mod requires three dummy loads.? One is for the QCX output, another is for the amp input, and the third is a high-power dummy load for the amp output.
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Note:? All transmitter tests should be done with an adequately rated dummy load connected to the RF output, even when no RF is expected.? Also, any input should be terminated in a 50ohm load, either the source transceiver or a dummy load.
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73
Evan
AC9TU
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Re: Enhance QMX+ To 10W SSB QRP
Dale,? Hans is working on a SSB system in firmware which will give an effective gain that will appear better than that without an external amplifier. We are hoping he will release it yesterday ;)
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73, Dan - W2DLC
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Hans,
Thank you for designing and producing such an excellent radio and kit. I received my kit in August and finally got it built just before the holidays. I have been on JS8 on 10m and recently switched to 40m and have been amazed to see where I've been heard with such a simple setup.
Merry Christmas and Happy New Year
Darrell KI4RXJ Kansas, USA
em28gx
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William WM9H
Paul K7VIQ
Chris / W2BPL
Dale Hardin KS4NS
Daniel Conklin