A/B Station Selector

A/B Station Selector Relay Boxes are now supplied with Amphenol connectors.

The A/B Station Selector is designed to provide a means to automatically switch an antenna between two radios in a two station environment. This capability adds a very useful degree of flexibility two a Single-Op/Two Radio, Multi-Single, or Multi-Two station, in that any antenna not currently in use is instantly available to either rig. (More on control of the A/BSS below.)

Each A/BSS is equivalent to a single pole double throw relay. An ingenious circuit using two SPDT relays per output port provides a very high port-to-port isolation (typically >80 dB). The circuit also incorporates a positive lockout feature to prevent the inadvertent “stealing” of an antenna already in use. Once selected, an antenna is not available to the second station until it is released by the first station’s QSYing to a new band.

Although the A/BSS relay, like any other relay-based device, can be manually controlled with a toggle or rotary switch, it was designed to be directly controlled by a Top Ten Devices automatic Band Decoder. A competitive two-radio contest station will have monoband antennas for each of the six contesting bands. An array of six A/BSS relays used with two Six Way Relay Boxes and a Band Decoder tracking each of the transceivers provides the ultimate in automatic antenna selection capability. For a diagram of the RF cabling between these devices, please refer to the first figure in Application Note 1. (The Band Decoders and 12 Vdc control lines are not shown in the figure.)

The A/BSS uses the same 12 Vdc relays and stripline printed circuit board techniques as does the Six Way. Its specifications are:

Power…………………1500W SSB/CW to 30 MHz, 1000W RTTY to 30 MHz

VSWR………………….<1.05 at 30 MHz

Load VSWR……………..<2.0 at 30 MHz

Isolation……………..>80 dB to unselected port at 30 MHz

 

Operating voltage………13.8 Vdc nominal

Current requirements……100 mA (approximate)

NOTE: There is an Application Note available on the use of six stacked A/B Station Selector Relays.

A/B Station Selector Pricing

A/B Station Selector…………………………..$ 75 + s/h