Hi Tom, All the equipment in the RF test lab is designed for 50 ohm. For all the testing I made sure to only use the 50 ohm terminations. In the video, I used a stronger signal because I wanted to sho

#v6

Ravi, I am also working on a modular uBitx project which puts all the modules in their own PCBs. I have posted all the project files on my AMP lab project page and you are more than welcome to modify

After some thought, I have decided that I will be doing another revision of the board that will be built in a modular fashion. I intend to connect RF lines together with SMA connectors to preserve sig

#v6

If I trace the signal through and there is noise appearing in the first stage then I don't think it's a matter of alignment. Plus I have tried that numerous times and it never helped. At this point I

#v6

It seems that somehow there is a bunch of noise making it into the radio. Just running it through the 1st conversion seems to bring the noise floor up enough for any reasonable signal to have adverse

#v6

I think I might have the reason that the display is causing this issue. In the code the touch control CS pin is pulled high after initializing the TFT portion. That pin is probably low on startup so t

#v6

I have published a YouTube video that goes through my findings. I was also trying to explain how the circuitry works. I show spectrum analyzer readings as I explain it so it might help. https://youtu.

#v6

Here is a capture of the (de)modulator from the spectrum analyzer. I Injected a 14 MHz sine at -60 dBm. On the uBitx v6 schematic this would be at TP20. Again, turning on or off the function generator

#v6

Okay, so I went through and recorded the gains and losses of each section. I did this because my RF mentor said that I should be able to easily hear a -90 dBm signal. Unfortunately this was a bit of a

#v6

Something I am wondering about is how I can tell if the 11 MHz filter is working properly. It seems to attenuate the signal quite a bit and when I inject a 14 MHz sine wave into the antenna line, this

#v6

Not sure why, but even after doing this fix I get no receive when I hook up to antenna. I should easily be able to hear WWV or FT-8 but nothing. All I can hear is a high pitched whine that only goes a

#v6

Curt, Thanks for the info. I tried going through the signal path and everything is running as it should be! I found out that the reason my sound was not sounding as it should was because of the same r

#v6

Hi all, I recently soldered up what was basically a copy of the uBitx V6. I used the schematics and pictures of the board to essentially create a copy of the uBitx v6 in KiCad. I found a few problems

#v6

Hi all, I am in the process of trying to run some LTspice simulations of the crystal filters. I am aware that one can model a quartz crystal using a series combination of a resistor, inductor and capa

#ubitx #filters

Hi all, I am in the process of building a uBitx V6 from scratch (bare PCB) and was wondering if there was a procedure to calibrate the radio. I see that there are three trimpots so I was wondering wha

Thanks for all the information regarding the building of the uBITX. I am more so curious about how the RF trace layout was done. I previously built the mcHF to master SMD soldering, and I found that o

Hi, I am trying to see if I can do a full assembly of the uBITX, that is, I want to start with a BARE PCB and hand solder on the SMD components. I was wondering if the KiCAD files were available or pe