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Custom may now be Standard

We believe your first choice should be Narda’s standard SEM switch series even if you have always ordered custom-part switches. Narda has more standard switches than any company in the industry.

But, if standard still won't do...

It's easy to determine the number of a custom-pick Narda switch that will correctly satisfy your intended application. Simply use the Part Number Chart. Referring to this chart, sequentially select the desired switch characteristics and options from Group 1 through Group 9. (The terms used here are defined in the Glossary ). Within each group, select the number or letter representing the desired configuration or feature and record it in the manner shown by the typical part number on the chart. (The open boxes below are provided to assist you in using the part numbering process).

Note that the last digit in part number Group 1 is indicative of envelope size and requires reference to the individual specifications and drawings in this catalog.

Select only one character from each part number group except for the Group 3 options. In Group 3, you many select as many options as applicable.

In Group 1, four items identified as “series number modifiers” call for further explanation:
6XXX - If a matrix-type switch is required, precede the selected series number with modifier number "6" (for example, specify 6080 for an eight-position matrix switch).

8XXX - If you are able to configure a required switch from the features and options listed here, but will be imposing your own design or test specification, precede the selected series number with modifier number "8" to indicate to us that our standard switch may require special treatment.

9XXX - When a deviation from a standard design is required (for example, painted housing instead of black anodized), precede the selected series number with the number "9." Then contact your Narda Regional Sales Manager (see Sales Representatives listing beginning on page 418).

To confirm that desired options are available for the selected switch series, please refer to the individual switch specifications in this section. Any other question that may arise in determining the proper part number should be addressed to your Narda Regional Sales Manager.

Glossary

The following glossary defines the various options and features available on Narda switches.

SPDT Switch - A single-pole, double-throw switch has one input port and two selectable output ports.

Multiposition Switch - A multiposition switch has one input port and more than two selectable output ports. Standard Narda switches offer up to 12 outputs operating from a single input. Unlike some switch designs, Narda multiposition models can be switched directly to any one of the available output positions without sequencing through any intervening positions.

Transfer Switch (DPDT) - A transfer switch has two independent paths that operate simultaneously in either of two selected positions.

Failsafe - a mode of operation in which the switch moves to the closed position when the actuating voltage is applied and always returns to a predetermined position when the voltage is removed.

Hot Switching - a mode of operation where a high power RF signal is continually applied to the RF contacts while the switch is changing positions. Should this mode of operation be necessary, specify a Make-Before-Break (MBB) type of actuation. It must be noted that switch life is a factor in this type of operation (1 Watt max). Contact Narda for more information.

Latching - Also called pulsed latching, a mode of operation in which the switch remains in a preselected position whenever the actuating voltage is removed or interrupted and holds that preselected position until a voltage is applied to another position. Latching switches specified without self de-energizing circuitry require pulse control, with pulse duration of 30 to 100 milliseconds.

Latching Reset - a mode of operation in which the switch remains in the pre-selected position whenever the actuating voltage is removed or interrupted. However, switching to a new position cannot occur until a voltage has been applied to the reset terminal to open all closed switching positions. This reset mode then permits random selection of any desired switch position and guarantees clean break-before-make switching.

Normally Open - a mode of operation in which all output ports of the switch are disconnected from the input port until a voltage is applied to maintain a selected position. The switch returns to its open position with the removal of voltage.

Normally Open Failsafe to Position 1 - In this mode of operation, (available only on multiposition switches), Position 1 is always closed until another switch position has been selected.

Make Before Break (MBB) - The make-before-break switch configuration is used in applications where RF power must remain “on” during switching. Also known as “hot switching.” See above.

50-Ohm Termination - With this option, each unused or open output RF port is internally terminated in a 50-ohm resistive load. 1 W CW per position max.; 5 W CW max input total per switch.

Indicator Circuitry - With the indicator circuitry option, a set of internally mounted contacts allow external monitoring of switch RF status. Some series require a steering diode 1:24:1 VSWR max.

Suppression Diodes - With this option, fast-recovery silicon recitifiers (diodes) are connected in parallel with the coils of the switch to suppress any transient voltage generated by the coils.

TTL - Selected position of the switch is controlled by a TTL Logic High. The switch requires only nominal +28 Vdc (additional 5 Vdc is not required).
TTL Logic Voltage Level: Low 0 to 0.8 Vdc
High 2.5 to 5.0 Vdc
TTL Logic Input Current: Low 0 mA
High 1.6 mA max. @ 3.85 Vdc
TTL Logic, High Input - Completely contained within the switch housing, this Transistor-Transistor-Logic driver circuitry enables the status of the switch to be controlled by the high level of the TTL logic input.
Manual Activator - With this option specified, the RF switch position can only be selected manually. Narda does not offer this as a standard.

Manual Override Activator - With the manual override option, each RF position of the switch can be selected either electrically or manually. Narda does not offer this as a standard.

Self De-energizing Circuitry - With this option, a set of internally mounted contacts or electronically generated pulses disconnects the driver voltage as soon as RF contact has been made. This option is only available with latching type switches. Suppression diodes must be specified with this option.
Power-Handling Capability (Watts CW) - Several factors determine the power-handling capability of a given switch design. A general indication of power capability versus frequency.

BCD TTL Decoder - Completely contained within the switch housing, BCD logic circuitry establishes compatibility of the switch with binary logic inputs.

MOSFET Driver - Completely contained within the switch housing, the MOSFET driver establishes compatibility of the switch with external CMOS (15 Vdc) control logic. This type of driver can be controlled by any DC voltage from 3 Vdc up to 15 Vdc. A MOSFET circuit is switched with voltage and requires virtually no current. Also, it does not require a separate +5 Vdc power supply.

Standard Solder Terminal - The standard solder terminal offered with switches is a gold-plated, double-turret terminal, as shown.

Solder (Loop) Terminal - As an option, Narda offers a glass-to-metal loop-type solder terminal, as shown.

Power Connector/Fast Disconnect - The standard power connectors offered with Narda switches are specified on the individual data sheets in this catalog. Narda switches can also be supplied with other power connectors specified by the customer.

Polarity - Either common-plus polarity or common-minus polarity must always be specified when ordering the following switches:

Latching

Latching Reset

Latching with Self De-energizing Circuitry

Latching Reset with Self De-energizing Circuitry

Make Before Break

Normally Open with Suppression Diodes

Failsafe with Suppression Diodes

Normally Open Failsafe to Position 1 with Suppression Diodes

Indicators

Polarity is not relevant to application for switches listed as follows:

Normally Open – No Options

Failsafe – No Options, except for XSEM323 or 130 Series

Switches with TTL logic driver, BCD decoder or MOSFET driver

Actuator Voltage - Standard Narda DC actuating voltages are 12, 15, 18, 24, 28 and 48. When other voltages are required, contact your Narda Regional Sales Manager for instructions.

Selecting a SPDT Switch:

The following pages describe a wide range of SPDT and 2-SPDT switches, presenting specifications, outline drawings and typical schematics for each model in this group. Important distinctions among these models are noted here to help the user select the correct switch for a specific application:

022 & 026
Two different SPDT switches with terminations. Frequency range up to 26.5 GHz with SMA connectors. Series 022 offers two externally mounted terminations. Series 026 is available with two internal terminations (refer to outline drawings for details).

023
A SPDT switch available with TNC, and Type-N connectors. Frequency range up to 12.4 GHz.

023 with termination
Similar to standard 023 switch, but also offers internal 50-ohm terminations.

025
High Performance, high reliability, low cost SPDT switch. Frequency range up to 26.5 GHz.

150
Two SPDT switches in a single package. Frequency range up to 26.5 GHz with SMA connectors.

156
Miniature Two independent SPDT switches in a single package. Frequency range up to 26.5 GHz with SMA connectors.