Variable Gain MX10160: The Tube Format of the Future
We use variable gain 10160 tubes for all of our builds. Why? Because they offer us the best utility, and best flexibility, while also simplifying our supply chain to reduce the cost to the consumer. Industry standard these days is to use MX10160 fixed gain tubes for fixed gain binos, and EGAC pigtail MX11769 format variable gain tubes for monoculars. However, this is a changing trend as newer designs such as the L-3 PVS-31 use a similar plate system for gain control.
Why not have both? MX10160 variable gain tubes, also known as 3 pin or 3 plate tubes, allow us to use the same tube format for both fixed gain binoculars, variable gain binoculars, and variable gain monoculars.
How these tubes work is that the two side plates carry power the same way that a normal 10160 tube functions. Instead of having a separate pigtail that has to be manipulated for gain control, there is a third plate added between the two power plates. If there is no contact with the third plate, the tube will operate on maximum pre-set gain, so it functions identically to a standard 10160 in a fixed gain housing. However, in 3 pin format housings such as the BNVD-1431 Mk.II, Photonis Spyron, and our in house modified 14 housings, resistance to the central plate determines the gain level and allows a full range of adjustability.
Another great benefit of using the same tubes for both monoculars and binoculars, is that it allows us to match tubes for binoculars as soon as shipments arrive. This allows us to match tubes as best we can, and then tubes that are more difficult to match just go into monoculars. A standard supply chain would force builders to either hold tubes for a better match in the next shipment, or compromise their tube matching principles in order to move inventory.
Hope you learned something!