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This kit is a simple minimalist controller for the Si5351A Synth kit (included with the ProgRock kit). It is intended as a programmable crystal replacement. It has three independent outputs with frequency range 3.5kHz to approx 300MHz, and can be optionally GPS disciplined.

Shop order

The features of this kit are as follows:

Documents and resources

Assembly instructions ProgRock kit: A4 format or Letter format
Operating manuals pr1.02 firmware Operating Manual: A4 format or Letter format
pr1.01a firmware Operating Manual: A4 format or Letter format
pr1.01 firmware Operating Manual: A4 format or Letter format
pr1.00 firmware Operating Manual: A4 format or Letter format
r1.00a firmware Operating Manual: FRENCH TRANSLATION
Si5351A Synth kit manual Si5351A Assembly: download here!

Many thanks to Gilles F1BFU for the French translation.

Version history

Version Date Features
pr1.02 10.Oct.2018 - Quadrature LO mode: Clk0/1 configurable with the same frequency but 0, 90, 180 or 270-degree phase offset
pr1.01a 22.Mar.2017 - Bug fix to pr1.01, there was an initialisation problem so it started up at 27MHz output
pr1.01 06.Mar.2017 - Added serial interface configuration option
- Changed Si5351A Code to all integer arithmetic - faster, smaller, more accurate
- In DIP switch configuration, LED flashes 4 times to indicate a button press is registered
pr1.00 20.Apr.2016 - Original kit firmware version


Kit photographs

a.jpg b.jpg contents.jpg

kits.jpg pcb-bottom.jpg pcb-top.jpg


Regulated Si5351A supply voltage a little high

Nick KG5N measured a regulated filtered supply voltage of 3.61V which is a little high, and 5.08V at the LM317LZ 5V regulator output. Lowering R5 to 36K resulted in 3.55V and using 33K resulted in 3.43V. Other people have also reported similar results.

Practically speaking, we have not heard of the Si5351A being damaged by this supply voltage although technically marginally out of spec; but if this worries you, then you could use a 33K resistor for R5 instead of the supplied 39K, as Nick KG5N has done. 


If you have completed a project using ProgRock and have information on it, please send it in - it will be interesting to other readers and constructors, to list them here. 

Using the QRP Labs "SoftRock" as a possible crystal replacement in "rock bound" VHF and UHF radios - detailed article by Clint KA7OEI, using the GE Mastr II as a case study.