


SPA-400 Four Place and SPA-600 Six Place Intercoms
- FAA TSO approved.
- Pilot fail safe feature allows pilot to always hear radios.
- Works with all brands of General Aviation headsets.
- Reversible face plate included for vertical or horizontal mounting.
- Radio priority assures that ATC hears only the crew member transmitting.
- Installation hardware included, including jack kit and pre-wired harness.
- WARRANTY: Five years parts and labor.

The Intercom That Set The Standard
Sigtronics pioneered the voice activated intercom market in 1974 and continues to deliver value and performance today in the 4 or 6 place FAA TSO approved SPA-400 / SPA-600 intercom series. With fail safe features that allow pilots to always hear the radio even if the intercom is off, and radio priority that assures ATC only hears the crew member transmitting, the SPA intercom series is the standard by which all others are judged.
Individual Mic Bias Allows The Use of Different Brands of Headsets
General aviation headset microphones draw power from the intercom or radio mic line. Some poorly designed intercom systems hook all the headsets to one mic line so that all the headsets must share the same power. Because different headsets have different power requirements, one headset may draw just enough power to work but there may not be enough power left over for any of the other headsets to function. With this type of design two identical headsets will work most of the time but get different types and models then you will have a problem. The only way to fix this is to modify or replace the intercom system with one that uses separate mic input lines. All Sigtronics intercom systems use separate mic input lines and do not have this problem.
Compact Size
Choose either rectangular (horizontal or vertical) or circular faceplate mounting configuration to fit anywhere in the cockpit. With a compact 2.5" x 1" sized panel, the SPA system will easily fit in the tightest panels. All installation hardware including jack kit and pre-wired harness are included.
High Noise Environment N Series
The SPA-400N / SPA-600N FAA TSO approved High Noise Environment Intercom Series is designed specifically for experimental, ultralights, warbirds, helicopters, and other high noise aircraft. Push to intercom as well as voice activated intercom is available as desired. Tested by Sigtronics at ambient noise levels of between 115-120 decibels, the SPA-400N / SPA-600N outperformed all other intercoms on the market, panel mounted as well as portable.
Features | SPA-400 | SPA-400N | SPA-600 | SPA-600N |
Headset Positions: | 4 | 4 | 6 | 6 |
High Noise: | No | Yes | No | Yes |
Size: | 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: | 4.5 oz. | 4.5 oz. | 4.5 oz. | 4.5 oz. |
Weight Jacks/Harness: | 5.5 oz. | 5.5 oz. | 5.5 oz. | 5.5 oz. |
Warranty: | 5 Years | 5 Years | 5 Years | 5 Years |
Price: | $247.00 | $270.00 | $288.00 | $328.00 |
SPA Faceplate
Adapts all SPA Intercoms to standard 2.25 inch round instrument hole.
Part Number: 900068
Price: $11.80

RES-401 / RES-601 Stereo Retrofit System
Full Stereo and Crew Isolate
Add full stereo capability and crew isolate to your existing SPA-400 / SPA-600 intercom installation with our RES-401 / RES-601 stereo retrofit systems. The RES system does not require removal of your existing intercom installation. The RES accepts input from a CD player, cassette player, AM / FM stereo receiver or Walkman. Music is muted when VHF / Comm is transmitting or receiving or when speaking on the intercom. Passengers can also be put on uninterrupted music if they desire.

Features | RES-401 Stereo Conversion | RES-601 Stereo Conversion |
Headset Positions: | 4 | 4 |
Size: | 4" x 2.9" x 2" | 4" x 2.9" x 2" |
Weight Unit: | 9.8 oz. | 9.8 oz. |
Warranty: | 5 Years | 5 Years |
Price: | $148.00 | $165.00 |
SPA-400 / SPA-400N PDF Instructions |
Installation and Operating Instructions Model: SPA-400 Panel Mount Intercom, Standard 4 Place. |
Installation and Operating Instructions Model: SPA-400N Panel Mount Intercom, 4 Place High Noise Version. |
Comm Radio Transmit Models: SPA-400 and SPA-400N Comm Radio Transmit Trouble-Shooting Guide. |
Helpful Hints Model: SPA-400N Helpful Hints for Communicating in Unusually High Noise Environments. |
SPA 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. |
Figure 4 installation drawing modification for specified audio panels, radios, and jacks. |
Audio Panel: King KA 134 Audio Panel |
Audio Panel: King KMA 20 Audio Panel |
Audio Panel: King KMA 24 Audio Panel |
AUX Audio: Auxiliary Audio Input |
Headset Jacks: U-174/U |
Radio: Apollo SL-40 |
Radio: Becker AR 3201 |
Radio: Becker AR 4201, 6201 |
Radio: Com 120 |
Radio: Flightline FL-760 |
Radio: Funkwerk ATR833 |
Radio: Garmin GTR 225 |
Radio: Garmin GNC250/XL |
Radios: ICOM A-200 and A-210 |
Radios: ICOM A20 and A21 |
Radios: ICOM A3, A6, A15, A22, and A24 |
Radio: King KX 125 |
Radio: King KX 155 and KX 165 |
Radio: King KX 170B |
Radio: King KY 97A |
Radio: King KY 195B |
Radio: King KY 197A |
Radio: MGL V6 |
Radio: Microair 760 |
Radio: Narco COM 810 |
Radio: Narco COM 810+ |
Radio: Narco MK12D |
Radio: Sporty's SP-400 |
Radio: VAL Com 760 |
Radio: VAL Com 2000 |
Radio: Yaesu FTA-550 |
SPA-600 / SPA-600N PDF Instructions |
Installation and Operating Instructions Model: SPA-600 Panel Mount Intercom, Standard 6 Place. |
Installation and Operating Instructions Model: SPA-600N Panel Mount Intercom, 6 Place High Noise Version. |
Comm Radio Transmit Models: SPA-600 and SPA-600N Comm Radio Transmit Trouble-Shooting Guide. |
Helpful Hints Model: SPA-600N Helpful Hints for Communicating in Unusually High Noise Environments. |
SPA 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. |
Figure 4 installation drawing modification for specified audio panels, radios, and jacks. |
Headset Jacks SPA-600: U-174/U |
Headset Jacks SPA-600N: U-174/U |
RES-401 / RES-601 PDF Instructions |
Installation Instructions Models: RES-401 and RES-601 Remote Stereo Music Switcher for SPA-400 / SPA-600 Intercoms. |
Operating Instructions Models: RES-401 and RES-601 Remote Stereo Music Switcher for SPA-400 / SPA-600 Intercoms. |