I have made tons of progress with my radioberry transceiver. In the last few weeks, after spending too much time reading AD9866 specs and experimenting with gain values etc, I decided to do away with hardware based Tx gain control. I instead set 0db attenuation in AD9866 TxDAC/IAMP and in software do a multiplication of the I/Q samples with a value between 0.0 and 1.0, depending on the tx level slider/knob. This works great.

At the moment, I can do CW with a teensy keyer. The speed etc can be adjusted with knobs connected to the front panel. The UI still needs a lot to be desired. Each knob (rotary encoder) does multiple things. That is where things fall apart. A long press puts them into different functions. It is hard to understand what the current mode is until you move the encoder and look for any changes in the screen.

This needs to be rectified. But I don't want to add to the pile of garbage on top of pihpsdr. I already removed a lot of stuff for radios I am not interested in. There is still a lot to be removed. There are global variables. There is this GTK mess. Yes, it is functional. But if you ask any programmer who has looked into the code of things that are "functional" but not "maintainable", you know the feeling.

At some point, I am going to call it quits and try to restart from the beginning. But for that, I will need to go back and get into a drawing board to write down some functional specification and then actually "design" the program. One of the decisions I have make is that, it won't support too many different types of radios.

Another trouble learnt on the air yesterday was a kind of noise being picked up by the microphone while transmitting. To the recipient, it feels as if some air is being blown to the mic intermittently. This turned out to be RFI/EMI being picked up by the part of the mic cable going into the PCB that is not shielded. If I pull the cable away from a nearby RF carrying cable, everything is fine.

So, yes, lots and lots of learning for me and I thank many other radio amateurs who helped me along this long journey and it is still ongoing.