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Dual Audio Panel Intercom With Stereo Music Input

  • FAA TSO approved.
  • Independent music inputs and full stereo capability.
  • Supports 2 to 8 headset positions, two positions with ability to transmit.
  • Pilot fail safe feature allows pilot to always hear radios.
  • Installation hardware included, including jack kit and pre-wired harness.
  • WARRANTY: Five years parts and labor.
SDB-K Intercom

Dual Audio Bus Systems
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.

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.

High Noise Environment N Series
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.



Features SDB-K SPA-4Si SDB-KH SPA-4SiH
Headset Positions: 8 4 8 4
High Noise: No No Yes Yes
Stereo: Yes Yes Yes Yes
Size Each Unit: 4" x 2.5" x 1" 4" x 2.5" x 1" 4" x 2.5" x 1" 4" x 2.5" x 1"
Weight Unit: 5.5 oz. 5.5 oz. 5.5 oz. 5.5 oz.
Weight Jacks/Harness: 7.0 oz. each 7.0 oz. 7.0 oz. each 7.0 oz.
Warranty: 5 Years 5 Years 5 Years 5 Years
Price: $683.00 $341.00 $717.00 $359.00


SDB-K / SDB-KH (SPA-4Si / SPA-4SiH) PDF Instructions
Installation and Operating Instructions
Models: SDB-K and SDB-KH
Stereo Panel Mount Intercom System for Aircraft with Dual Audio Panels.
SDB Panel Template
Models: SCI, SDB, SPA, and Sport 200
Panel Templates for intercoms.
Radio Keyline Modification
Model: SPA, SDB, SCI and Sport Intercoms
For KMA-20 Audio Panels and ICOM A220 Radios.