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Dual Audio Panel Intercom with Stereo Music
(DAI Part# SDB-K)
The Sigtronics Dual Bus Kit (SDB-K) includes two Model SPA-4Si intercoms specifically designed for installation in aircraft using dual (separate) audio buss' systems (i.e. aircraft with two audio panels). The SPA-4Si units allow each pilot, operating separate radios, the convenience of voice activated inter cabin communication. In addition to operating their respective radio systems independently, the SPA-4Si units add independent music inputs and full stereo aviation headset capability. Optional passenger connections allow intercom and stereo music positions with radio receive ? No radio transmit.

Adaptable System
The kit consists of two SPA-4Si intercoms (with the option of adding up to 4 more SPA-4Si units) each with their own operating controls and radio interface. An interconnect line allows intercom communication between the units yet keeps the VHF audio systems separate. When transmitting through their respective radios, each side will hear the other's transmission unless transmitting simultaneously. Radio transmission is also possible through either unit even when the units are "OFF."

The SPA-4Si units may also be used as a dual intercom system in aircraft without dual audio panels. This is convenient where it is desired to have separate conversations between pilots and passengers. Contact Sigtronics for information.

High Noise Environment H Series Version
The SDB-KH kit has two model SPA-4SiH intercoms. The "H" version of the SPA-4Si has all the above features but is specifically configured for very high noise environments.

Compact and Lightweight
Reversible face plates are included for either vertical or horizontal mounting, circular mounting plates are also available. All hardware needed for installation, including jack kit and a pre-wired harness, is included. Each unit is only 4" x 2.5" x 1" in size and weighs 5.5 ounces for the chassis, and 7.0 ounces for the jacks and wiring.

FAA TSO approved.
Independent music inputs and full stereo capability.
Supports 2 to 8 headset positions, two with ability to transmit.
Pilot fail safe feature allows pilot to always hear radios.
Installation hardware included, including jack kit & pre-wired harness.
Size 4" x 2.5" x 1"
Weight Unit 5.5 oz.
Weight Jacks & Harness 7.0 oz.
Warranty 5 Years