Elektronika MK-52: The MK-61 big brother?

[jebem]

(02-18-2015 06:22 AM)jhl Wrote:  I also found out the hard way that the front face of the VFD is also coated with a transparent conductive layer and connected to filament potential (-27V + AC). I assume this has to do with directing the electrons towards the rear of the device?

Excellent additional information on how to repair this interesting calculator!
We keep learning from others all the time.
Thank you for that.

Concerning the high voltage present on the front face, I didn't realize it was present.
Well, we know the VFD works much like a vacuum triode, where the cathode (filament) must be negative in respect to the anode.

So your explanation makes sense to me, but other expert people on physics here can give a more elaborate explanation.