KUATRON OPTEL FE LCD 1973
This is the following FE (Field Effect) generation of oval Optels after the first BWC Swiss. Kuatron was a Korean brand that was very likely subcontracted by Optel to produce the hand-soldered modules. The large goldplated models can be found with various branding that might contain both DSM and FE displays. FE modules appeared soon after the first DSM types and have a completely different circuit layout thus they are not simply transplantable between each other. The FE circuitry provides far to low voltage to power the heavy-duty DSM display however FE displays will usually work when transplanted to a DSM module. The round cases were made in a few versions and are opened either thru the crystal or the snap caseback. The module is fitted with three screws to the casing or the dial and simply falls out from the case.
Oval modules are powered with obsolete large 355 batteries the same as Pulsar. A common 357 cell must be kept in place with a spacer and connected properly to the negative and positive clamps. Both DSM and FE oval modules (despite different circuit layouts) can be used for parts as most components are identical including the microchips. The setting manipulators and display frames can be transplanted quite easily. The graphite-rubber conductive pads on the plastic display frame can be pulled out and replaced or made from scratch with special repair-kits for remote-control buttons. One important note! Field Effect displays require special polarizing filters otherwise the display will appear blank. They are placed on top of the display and usually affixed with the metal frame although some models might have them on the inside of the case or dial. These filters can be made new from a piece of developed camera film.
FE displays are far simpler than the multilayer DSM and do not contain any metal elements. The glass is also subject to damage on the corners due to stress and shock but it is far easier to repair the broken traces with silver epoxy. Repairs of missing display corners might be attempted with ordinary heavy-duty epoxy coated with some silver paint or epoxy on the bottom surface to create display traces. FE displays from 1973 have practically remained unchanged until today thus they are not that collectible as the rare and akward DSM. This is reflected in the values as a NOS FE Optel might sell for 300$ whereas a DSM for 600-700$. Optel boxes are a rarity, the one pictured is original with label but appears to be a workaround as the pushed-to-fit interior of the box was significantly to small to hold such a thick watch ;)
Keywords: kuatron, dsm lcd, field effect, optel
Market value: 100-450$ (version, condition, box)