Make sure you are using the latest release of the compiler, 1.8.4 and which code are you starting with?

It seems like last week when I downloaded 1.8.4. I had the same issue before that. Howard

If you are running on +24V I would change C98 and C99 to 35V parts, they won't last very long on 24VDC. Howard

I would be in favor of adding a frequency on 20 Meters. I have much better luck getting QSOs up there. Howard

I built the 70 watt model. I changed the 2 IRF530s to 4 IRF520s. The IRF530s oscillated and failed quickly. They also run very hot. The IRF520s run much cooler (2x as many junctions) and are stable pu

Bruce: I have seen this problem, but only with my power amplifier. It is caused by RF getting into the audio stages. The stock audio input is unshielded, you can try replacing the cabling to the uBitx

#ubitx

Also, make sure you are using the latest version of the Arduino compiler.

#bitx40 #firmware

For my power amp for 20 meters I built a 5 pole Chebychev filter-2 -0.9 uH inductors 270 pf for input and output caps and 430 pf for the center cap. This is a 75 ohm design, my dipoles are closer to 7

You paid too much, I picked it up for $5. Not sure what to do with it, and it needs special mating cables to use it. If you have an interesting project for it that can't be done with an Arduino, I'd l

Have you posted the design? It sounds interesting. Howard

I tried a similar approach tonight in my simulator. Seems promising to me also. Once I fix my uBitx, the Arduino died, I will try it.

I don't know what the FCC does, but I have been through this on the product validation side. I have worked on several EMI certifications. You need at least 3 dB margin on the spec to get approved with

After much thought, and reading all the threads, and speaking to Allison (who has not commented to me on this yet) I think I have a good solution to the harmonics issue, not the spurs. We know that th

HI Asher: Is that for both the harmonics and the spurs? Thanks, Howard

All: Have you considered changing the LPF L1 to L4 with a bandpass filter that is tuned for the operating band? That should help both harmonics and spurs and improve receive performance as well. Howar

#ubitx

Can we change CLK#1 to 66 MHz? Then the spur should disappear? Or is it 66 MHz already?

#ubitx

I meant CLK#2.

#ubitx

Brown is 1 black is 0, brown black brown is 100 ohms. 10 ohms is brown black black. Check it with an ohm meter.

This should help. I use it in my BME301 class. Howard

I am using the MAX9814 with my uBitx. It has a selectable maximum gain 40, 50 or 60 dB. I am using 40 and it is too high. It picks up all the small sounds in the shack when you are not talking. Unfort