Here's my latest design notes (I should have included this with the pictures...) The ProgRock is designed to be a programmable crystal replacement. It uses an Si5351 synth board to generate pre-progra

#si5351a #progrock #vfo

Here are some pictures of the progress I've made so far. In the first two pics "parts top view" and "parts bottom view": The Synth board on the left (one with the crystal) plugs into the top of the Pr

#si5351a #progrock #vfo

Thanks very much Mont. Your explanation was clear and worked first time. I missed that completely in the instructions!!! Am grateful for your help and all the other useful info in this group. Cheers a

#vfo

Sounds like you are just a little mixed up about what mode you are in. > The right button ... switch[es] to preset mode if momentarily pushed in. Actually, it is switching to "Config Settings Mode" an

#vfo

Use the rotary encoder to cycle through the presets which you have set up, in the configuration menu. To choose a preset to load into the VFO, press the right button. Are you following this above? 73

#vfo

Newbie CW sent with love and enthusiasm is the best. Keep at it! CW will grow on you! Dave

#vfo

My two recently built vfo's act exactly the same as each other. When first powered up, they gave the message,“Diagnostic Mode” then displayed the 0 preset frequency of 10,000,000 mhz. The right button

#vfo

A long time ago when updating the U3 to U3S it was necessary to remove pin 12 of the synth unit. I removed all mine and blocked the hole in the header. Then it will only go one way. Pin 12 remains red

#si5351a #progrock #vfo

That's a GREAT idea... If only I didn't already have all my Synth boards built... Every time I go to plug in a Synth board, I have to pause for a moment to think about orientation. Your way is so simp

#si5351a #progrock #vfo

When I built my last synth board, I used 1206 resistors in place of the vertically mounted components just to relieve the boredom of lockdown. Doesn't work for horizontally ones. No problems found and

#si5351a #progrock #vfo

My latest design path... I decided to keep the ProgRock in line as it has one feature I don't yet in my VFO code... GPS disciplined frequency control. For awhile I was struggling on the problem of whe

#si5351a #progrock #vfo

Sounds like a great idea to me.

#si5351a #progrock #vfo

Actually, looking over ProgRock's circuit diagram, I don't think I even need the ProgRock board. I can simply connect one Si5351a Synth board's output clock 0 to the crystal input at pin 2 on the seco

#si5351a #progrock #vfo

THANKS for pointing me in the right direction. I thought I saw something somewhere about "invert"ing the signal. I'm sure having a lot of fun with your kits. :) 73 km6wt

#si5351a #progrock #vfo

Yes, that would work, if... I was only interested in getting to lower frequencies. Changing the crystal on the Si5351a breakout board also works to get lower frequencies. Hans did this for the 180m QC

#si5351a #progrock #vfo

Yes, I saw that. But Hans is sometimes a super-perfectionist:-) I've used many Softrocks with 7474s and as I am sub-perfect they seem to me to work adequately. As for complexity, my suggestion is for

#si5351a #progrock #vfo

KM6WT I think you are right that if you use dividers for lower frequencies then the phase offset would be different for different division factors. Maybe a workable scheme might be to use division of

#si5351a #progrock #vfo

Thanks for your input Arv. I did try that, and it works fine for a single clock. But if I remember right, I could not get two clocks at 90° phase shifted. Maybe I did something wrong, or missed someth

#si5351a #progrock #vfo

Hello Mont For 180-degree phase shift you just set Clk0 and Clk1 to both be sourced from PLL A, and both with 0 phase offset. Then simply set the Invert bit in the control register for one of them. It

#si5351a #progrock #vfo

Perfect!! Thanks for your input Hans. AND for sharing all your research 3+ years ago. :) :) Yep, I was thinking the same thing. Probably easier then hooking up the serial port lines. In either case, I

#si5351a #progrock #vfo