BinaryRock

[Cable Guy]

Wasn't planning on another update, but I learned something new today. Sharing for those about to go down this road.

There are two different kinds of rotary encoders lol. Quadrature where both wires get a pulse regardless of direction (just timed differently), and the old ones like the old cobra radios used for the channel dial where each direction gets its own switch and only one sends in each direction.

The ones I foolishly ordered were the latter type (and delayed in the mail, of course) so I tried the cobra ch dial encoder today. It didn't work with my code. But now, it does. I added another switch in the firmware to select the encoder style so both can now be used.

And for some good news. I now have too much user config data to store it in userrow so my only choice is to leave the chip unlocked. If I lock them, the fun stuff would not be able to be changed and I'm not gonna be that asshole.

The first few are done but still missing buffer transistors and therefore haven't washed them. The faster transistors should arrive tomorrow and I hope to have some for sale by next week assuming I don't find any more bugs. These here already have a home lined up but I will make more next weekend.View attachment 77792

I gotta say, that black pcb and board layout is slick.

 

[brandon7861]

Variable encoder demo

 

[brandon7861]

I gotta say, that black pcb and board layout is slick.

thanks!!

 

[SuperLid]

@SuperLid
I connected a rubidium standard to the SA reference input and connected the reference output to the front input hoping that the rubidium source had a better phase noise than the SA in hopes to get an idea what the phase noise of the SA is.

I got this, 85.85dB down at +100Hz offset with RBW at 1Hz:
View attachment 77728

I then programmed the 5351 to output 10MHz and measured that. Since I did not calibrate the frequency yet, I simply offset the second marker by the same 100Hz and ran the averaging again. This time it showed 88.43dB. Somehow it is better than the rubidium source even though the rubidium was still being used as the reference.
View attachment 77729
Not sure how to interpret that, but if I adjust the voltage on the binaryrock board, the carrier peak and the second marker (and the entire noise floor) move in sync.

I don't know if the phase noise of the SA is limiting the measurement, but I am going to call this good enough. I did notice that the SMA on the rubidium was a tad loose when I took it all apart though, so maybe that should have been tightened better.
View attachment 77730

I have been wrapped up in antennas and other things lately. I would like to contribute to this, but I don't have the bandwidth yet. I have an Agilent SA here, in addition to several others. But my 2 Aeroflex CSM's are down now. I have a couple of Rigol's, but I don't like them that much. They are probably on par with that Siglent you have there.

Keep posting and I'll read when I can comprehend lol.

SL

 

[SuperLid]

I could make a slim version for xtal replacement only, but the firmware doesn't need to be changed to use it that way. It is easier to upload the same sketch and just change a few options at the top since I need to program them, let them run for a half hour, then reprogram them with the calibration data anyhow (now the slowest part of the process). The edge connector makes programming these a breeze though.

There will be hardware options too. You can select XTAL or TCXO, and for an AM only radio, the xtal is plenty. I also not populate the buffer parts if you want the 5351's output directly, kinda nice if you want to use the software power settings. And that brings up the hardest question.

Next task is to have the user configurables in the eeprom in a way that lets me provide the user the capability to update that info from terminal without having the user dig into the entire code.

I highly recommend NOT using xtal. The few experiments I have performed with the 5351's, the TCXO became mandatory for stability. The 5351's I have, came populated with xtal. So, I got some TCXO's that will replace them.