Clare-Pendar Series S820
Clare-Pendar Series S820 is a tall reed switch series.
There are at least three different shell styles for these switches. One design (“Type 1”) is secured with screws placed down through the top of the shell, similar to Micro Switch Series KB. There are two recesses in the case at the top to make way for this, in opposite corners. The exact mounting method intended has never been observed: In the only clearly-visible example of this type, the screws appear to be omitted. This variant was in production in 1971 and 1972, based on date stamps discovered.
A second design (“Type 2”) has a profiled shell with no screw holes. Only one example of this has been seen, tentatively dated to 1976. This appears to be the design shown in the diagram within the 1986 catalogue entry (the photograph depicts a different design), where it is depicted with plate retention clips.
A third design (“Type 3”) is similar to the above, but has the plate retention clips in opposite corners. This is the design depicted in the photograph in the 1986 catalogue, which is shown below:
This unidentifiable example almost fits the part number S82010 J7 L1 (J7 = illuminated, L1 = tinned leads). However, it is distinctly lower in force than the nominal weight of 2.5 oz suggests, which means that it could be a lower-weight type.
- Clare-Pendar keyboard — the switches are branded “CLARE/PENDAR”, and are part S820-10 from 1971 and 1972, with only the screw recesses clearly visible (“Type 1” switches)
- CDC CC609D terminal — marked “S820” and branded “CLARE-PENDAR”, with screw holes; from the modification log on the unit, the switches are from no later than 1975 (“Type 1” switches)
- Unknown keyboard, possibly from week 44 1976; these switches are marked “CLARE-PENDAR” and “S820”, and lack screw holes (“Type 2” switches)
- “Vega 2200 Series” keypad, possibly from 1983 or later, with “Type 2” switches.
Both documents were kindly scanned in by Electro-Mech Components, who took over part of the Pendar range.
- S820 and S880 catalogue entry, September 1986 (front and back cover of the catalogue included)
- S820 and S880 catalogue entry, older scan with L1 modification annotation (tinned leads)
- S820 entry, Deskthority wiki (all my prior notes)