R2LC0? What's your guess?

A fuzzy C08.  The top of the figure is symmetrical; if it were a 6 one side would be darker than the other.

The 06 would have slightly different detail. Marker lights may be different.

Well, if you showed the ENTIRE circuit board- one can tell.

The circuit board and components is ALSO different- not just the processor chip- specifically the radio receiver section. If it has a tuning coil- it's not a C08.

Again, an 08 has a non tunable radio section (LT 455FU)

Earlier versions of the R2LC example -06 have a tunable coil.

Pro tip- you most desire a C08 not just because of being the latest firmware code and most compatible- but ALSO- the newer radio section that is solid state and laser trimmed, thus less prone to aging and going out of "tune" with the 455KHZ signal from the base.

@Vernon Barry posted:

FWIW, some of the 07 versions did not have the turning coil, here's one with and without the tuning coil.  Also, the LT 455FU is on the older and newer versions, just in a different spot on the board.  The added component was the D455 Ceramic Filter (yellow component).  Since many of the components were moved around, removing the coil resulted in a lot of changes in the board design.  They also went from the MC3361BD receiver to the MC3372D.

Added filter for the C08 and later boards.

Probably more than you ever wanted to know about the R2LC.

What is the tuning coil for?

@romiller49 posted:

What is the tuning coil for?

On the original design, it was to tune the 455Khz track signal center frequency.  However, in later versions, it was replaced using a ceramic filter that needed no tuning to increase reliability.

Sometimes with the older versions, you can tune them to restore operation if the filter center frequency drifts with component aging, etc.

Thanks John.

Well it sure looks like a C08 based on the descriptions above and the picture below!

Thank you John, Vernon, et al. I really thought the label looked like it had a "06" on the end - good to know it's an '08"

George

Almost surely it's the -08 version, I've never seen a -06 version with the ceramic filter and no tuning can.