Indra, You are able to measure it at the predriver, it doesnt mean that the oscillatiins are starting there. The easier way to know that is by turning off the power supply to each stage. - f

#ubitx

Indra, 1. Are you using a dummy load to test? 2. What is the idling current set for the PA? 3. Can you disconnect the LPF from the tx power chain and add a 50 Ohm resistor at the input and test again?

#ubitx

Congrats steve, I have been running a version of FT8 on the ubitx, on and off. It is amazing what it can do.

Ok! At the moment, the decodes are pretty raw. That means, you can script it pretty much anyway. I can even send "kilroywashere" and confuse everyone. - f

I didn't even know of the adif files! This is what happens if you spend too much time with direct conversion radios - f

Jim, The initial batch of sbitx, meant more for homebrewers and SDR buffs will be available before 1st June. Yes, it will be sold through hfsignals.com. I would urge you to wait for a whilw before ord

Buddy, Yes, I have kept an eyes-free option, though this may need some work. - f

It doesnt do JS8call yet, but no reason that it cant. - f

Randall, The idea for now is to get a few hundred sets into the hands of hackers to start adding to the code. I am writing enough code that it has hooks that others can latch onto. Just some UI work r

Peter As usual the last few things are taking the most time. But here is the update: First, I hope to bring a finished piece to Dayton to show and tell. We can't sell it there but we will surely be ta

Jack, Please consider a Kindle version as well. The dead tree print will take a month to arrive here in India. - f

It looks like there is an impedance mismatch. The 45 MHz filter needs 1500 ohms termination.

#calibration #filters

Gerard, Do you have any way of measuring the precise output in dBs? Alternatively, do you have a step attenuator? You can try taking out one block of circuit at a time to see which ones are the culpri

Peter, The Raspberry Pi 7 inch displays are out of stock everywhere. We tried with the other available HDMI 7 inch displays from China, they are of varying quality. We are finally, getting the display

The antuino code can be adapted to simply do this. The bigger question is, how are you going to measure the forest of outputs? You will need a frequency domain instrument like a spectrum analyzer or t

I looked around and found most GUIs to be very complicated for future hackers who were coming from Arduino backgrounds. Instead, I wrote a simpler GUI that works with encoders, mouse or just touch wit

Tim, which bitx are you using?

I built one that way. I tried all logic gates 74LS, 74HC and 74xx and finally settled on 74LS04 with feedback. The receiver, worked, sort of. The signal handling was really poor, sensitivity was horri

The sbitx can put out 40 watts, but it is not recommended, as it can produce IMD. There are no plans for anything more than this power. The low pass filters, heatsinks and the power supplies become ex

The RP400 may not work as it can't take the audio codec board (as far as I know). The connector line up is not of any particular significance. The raduino connector has 0.1 inch pin spacing. There is