0.6.1 sub revision:
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Simple improvements that make the boards easier to solder:

- black silkscreen, white solder mask
- improved footprints, better text positioning
- removing lots of 0 Ohm jumpers that are really used
- PCBs are 1mm thick now

Mechanical changes: 

- removed speaker hole(RF), as the Chinese case uses low profile speaker

Schematics changes:

- thermal sensor and LO heater removed from the RF board
- Potato chip devider in LO(U11) instead of 74AC74
- Parallel interface for the LCD no longer supported
- Six pin Nucleo debug connector for easy programming/development(UI)

0.6.2 sub revision(11 Dec 2018):
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Simple improvements that make the boards easier to solder:

- improved buttons footprints on the UI board
- improved footprint on the aluminium caps
- removed lots of 0 Ohm jumpers that are rarely used(UI and RF)
- polygon connect method for all alu caps on the UI board improved

Mechanical changes: 

- none

Schematics changes:

- Codec Digital supply now routed to MCU regulator
- Codec Analog supply still from RF board 3V supply
- The SWO pin on the Nucleo debug connector is wired now

0.6.3 sub revision(11 Feb 2019):
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Simple improvements that make the boards easier to solder:

- improved relay footprint to support G and F type

Mechanical changes: 

- BNC replaced by SMA connector

Schematics changes:

- none