Max-Gain Systems purchased the remaining inventory of a super-high end manual RF coaxial switch from the former Electronic Switch Company (no longer in business). This coax switch series was the “top of the line” custom manufactured in Germany to very high specifications, and aimed at the commercial and military markets as well as for higher-end amateur users.
The switch wafer used is of German manufacture, and is similar in size, appearance, and function to the famous Radio Switch Corporation of America # 86. This switch uses true wiping, self-cleaning contacts, heavily plated with coin silver. The voltage rating and isolation are further increased by using every other position, skipping one between each one that is used. The connectors are installed directly on the switch contact terminals, for essentially “zero” internal lead length – a must at higher frequencies! The double – opposing, wiping contacts make this switch perfect for switching anything from fractions of a microvolt to several kilovolts (see specs below).
This switch has six connectors; one input, and five selectable outputs. The enclosure is custom made of all aluminum, and is RF tight. The indexing is the smoothest, most precision that we have ever seen, and we have seen quite a few! All connectors are top quality silver plated, with gold center contacts.
All connectors are mounted axial, not radial. The coax connections are all on the back panel, not the sides, for neat station appearance and easier positioning on the radio table. Two aluminum mounting angle brackets are included if you wish to mount the switch semi-permanently (by screwing the brackets into the shelf or table). The design and weight of this switch, together with the smooth, easy switching make this unnecessary in most applications.
The large knob of modern design clearly indicates current position, and is of perfect size for easy position selection. The switch position may be rotated in either direction, for the quickest path to the desired new position.
The power rating on these switches is limited by the connector type chosen, in that the switch itself is capable of more power than any of the three connector types. For both type “N”and type “UHF”connectors, the maximum power handling capability is about 6 kilowatts at 30 mhz into a matched load. Maximum power handling of course decreases with increasing frequency . BNC connectors are rated at far lower power handling than are the “N” and “UHF” types.
Laboratory measured insertion loss specs are:
- 14 . 275 mhz : -37 . 4 dB
- 51 mhz : -24 . 87 dB
- 145 . 6 mhz : -16 dB
- 440 . 6 mhz : -27 . 93 dB
- 500 mhz : -18 dB
At 30 mhz, the insertion loss equates to an SWR of 1.074 to 1!!! WELL better than 1.1 : 1
Here at MGS, we hipotted one if the model N-105C’s, to see what maximum voltages the switch could stand. When we tested from the center pin of one “N” connector to the center pin of an adjacent, (not selected) position, the switch withstood just over 6,000 volts! When we tested one of the silver-Teflon type “N” connectors from center pin to ground, the connector withstood 4,000 volts. The connectors themselves are the limiting factor as to voltage for this switch, as the switch withstands more than the best of these series of connectors.
Model N-105C 5 position Coaxial Switch, Type N female connectors