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I put my v4 back together with the stock L1-4 toroids.? The only change I made was to C81.? I put a 2.2nF in parallel with the 470pF that was there.? Here are the CW results with 12 volts to the

Justin, FYI, There is a Groups.io for that work.? It is here: /g/ucx The original project was called ?CX, which the group felt was too close to the QCX/QSX names that are used by

Looks really cool. Upon reading his explanation of his code, I need to revisit my assumption that writing assembly is almost never worth the effort now days. Although it looks like he put an

After getting my feet wet with the UBITX I ran across this interesting sounding project: https://antrak.org.tr/blog/usdx-a-compact-sota-ssb-sdr-transceiver-with-arduino I sent off the Gerber files

The AL of a T30-6 core can vary +/-5% of the nominal value, and inductance is proportional to AL. https://toroids.info/T30-6.php Yet another handy factor to blame bad results on. Inductance is

The plot thickens. The most recent observation is that there is a HUGE variation in the inductance of the toroids depending on the turns AND the spacing.? I tested this because my first attempt at

Farhan, Perhaps driving harder will help, worth trying. However, the middle picture of this post shows TP1 when operating 40m CW: /g/BITX20/message/87328 The first image here shows

As Curt found, increasing C81 seems to be key here. The filter and mixer see much closer to 50 ohm loads with the v3 values of C81=0.1uF, R83=10ohms. But v3 had too little power on the high bands. I

I think I am done playing with LTspice.? Here is the circuit I plan to change my v4 to: The LTspice file is attached. I wanted to balance out the input impedance issues with the gain issues at

An interesting new contribution by "NerdRalph" - this may help the uBitx Raduino code size - ArduinoShrink?replaces Arduino AVR Core functions with smaller and faster versions. The Arduino Blink

Testing on-air? There's a tuning device that was very popular a few decades back, and schematics are still available online. It uses a 555 to generate approx. a 30% duty cycle CW key-down, and you

Jerry, I am still playing with LTspice and have not yet gotten to building the circuits.? In my playing around I did come to the realization that if I did the transformer impedance match I would

The CW signal is generated by injecting a DC current into the diode mixer, upsetting the balance. At present, the R104 and R105 inject approximately (4.4V/ 3.2K =) 1.5 mA of current into the

Curious, that's two bad 0.1uF 1206 caps found shorted recently. Both of them on the 3.3v supply rail from Nano to the Si5351. The Raduino has two such caps on the 3.3v rail, and three identical caps

I finally got back into the shack after almost a month.? And I am glad to say, the uBitx lives!? ?I want to thank everyone for the excellent advice!? ?I started by removing C1 and replacing it

Bob I am agreeing with the others. If you don't have a power meter, well you could try a cq in cw and see what RBN spots you get. If you get a few spots on a band with signals, likely the transmit

Given the variation in impedance as seen in the simulations of ideal components, it's amazing to me that the output power manages to be as flat as it is. Fun to figure out what all is going on here,

The problem of low SSB output where CW output level is good, might be something as simple as a defective microphone. Some of the microphone cases have the sound hole covered or miss-aligned with the

Bob, When I see an issue with SSB transmitter power, the first test is always to check the CW power. ?Based on your data The problem is not Q90. More likely it is a BFO adjustment. ?Ashhar Farman

Here is a general question: If Q90 is bad, will there still be a CW transmit signal? In other words, will Q90's health affect both the SSB transmit signal AND the CW signal...? The reason for the