A 5,000 step optical encoder that was part of an Argo Navis kit update of a Celestron C8. The sticker on the encoder says "Optical Encoder 5000Y"
The encoder appears to be working satisfactorily - as tested by connecting to Argo Navis unit and turning by hand.
Included, if wanted, is the mount arrangement supplied with it that includes 2:1 gears to achieve 10,000 steps per single rotation of a shaft. Includes cover to cover the gears. In mount, encoder is wired to a telephone-style jack to connect to cable to Argo Navis.
$40 plus postage.
Sorry about out-of-focus photos - best my mobile phone could do.
