Hi Pascal, This BSC22DN20NS3 part looks excellent for class-E use, I am surprised with the fast switching times and the amount of current it can handle. The gate capacitance is maybe a bit on the high

#qcx

Allison, That would be a good thing for the QCX main frame users. His 20db Well, with the QCX phase-shift you can get about 40dB rx side-band rejection in the 200-1200 Hz range, but higher up it will

#qcx

Hi Hans, No need to change anything. QCX-SSB is implementing quadrature generation from the start and has an exact 0 and 90 degree phase shift, like QCX firmware does. There was however at some point

#qcx

Hi David, This all suggests that the 5V supply is too low. Not sure what the reason of this could be, maybe some of the mods is pulling the voltage down? Here are some voltages to check on IC2, (assum

#qcx

Pascal, Many thanks for the ideas regarding designing planar coils. Definitely going to look into this and see if a small filter bank can be produced this way, potentially to make a better multiband Q

#qsx

Very unlikely, it is probably the last thing that will break in your QCX. If broken, the display would not show any text. But.. due to some short, IC11 can become very hot sometimes switching off due

Hi Steve! Hope you are doing well. Yes, that looks absolute wonderful. It would be nice to make a stack of PCB with embedded LPF coils as shown. Suprised to see how compact these coils are. Is this fo

#qsx

Thanks John. This is quite promising, will have a look into this filter design. Wondering if there is any minimum separation needed for the coils, or can they be clubbed together as close a possible?

#qsx

Pin 14 on IC2 should be 5V at receive. You can measure this from the bottom of the PCB, but you can also temporary remove the LCD and measure it from the top of the PCB if you like.

As Hans very well describes there is the risk of false decodes due to the matching against a list of known stations and the weak protection of the message integrity. At the time when Opera came out, q

Hi Pascal, Very nice to see you experimental setup. Regarding the air-wound coils in your class-E PA, what power output /efficiency do you get? I am also thinking is similar directions where LPF coils

#qsx

Check if the RX line is 5V in receive.

Hi David, Good to hear that the QCX-SSB transmitted audio quality sounds good now! Note that regarding your other finding, on startup the firmware tests which of the hardware modifications are applied

#qcx

Hi David, 1. Regarding point 1, I recommend upgrading to firmware 1.01x: https://github.com/threeme3/QCX-SSB/releases Probably, I have seen today your original issue of bad audio quality you was writi

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Hi David, Very good! Regarding point 5, U2 pin 25 should go to 0.55V in TX mode only. Regarding point 2; if you like to make a direct QCX-SSB to QCX-SSB contact on 40m during the weekend, let me know

#qcx

Hi Allison, Great story about your razzing friends, but anyway the blame is on me :-) as you probably used the first version R1.00 and it was far from ready. One serious issue with R1.00 was the unrel

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Hi David, In addition to my previous mail, here are a few more suggestions: 4. Set a suitable SSB envelope gain with the "TX Drive" parameter in the menu. This parameter specifies an additional microp

#qcx

Hi David, Sorry for my bit slow response and congrats with the build and so far the working receiver. Here is what I suggest: 1. Upload the latest (unreleased and experimental) firmware: https://githu

#qcx

No, CAT control is not used by FT8 for the actual FSK modulation and do not think QCX currently supports a CAT command that can transmit frequencies on command. FT8/JS8 can be done with a QCX, but you

Hi, Yes, the lost receiver phase relationship for 80 and 60m is a known issue in R1.01d. It has been fixed in a experimental version R1.01r here (yes, with plenty of new features): https://github.com/