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Panel Mount Intercoms
SPA Four and 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 & pre-wired harness.
Sigtronics SPA-400 Intercom
SPA-400 Four Place
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 / 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 / 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 / 600N outperformed all other intercoms on the market, panel mounted as well as portable.

SPA-400 Four Place
SPA-400N High Noise Four Place
Size:
4" x 2.5" x 1"
Size:
4" x 2.5" x 1"
Weight Unit:
4.5 oz.
Weight Unit:
4.5 oz.
Weight Jacks & Harness:
5.5 oz.
Weight Jacks & Harness:
5.5 oz.
Warranty:
5 Years
Warranty:
5 Years
Price:
$216.00
Price:
$237.00
SPA-600 Six Place
SPA-600N High Noise Six Place
Size:
4" x 2.5" x 1"
Size:
4" x 2.5" x 1"
Weight Unit:
4.5 oz.
Weight Unit:
4.5 oz.
Weight Jacks & Harness:
5.5 oz.
Weight Jacks & Harness:
5.5 oz.
Warranty:
5 Years
Warranty:
5 Years
Price:
$252.00
Price:
$288.00
RES-401 / RES-601 Stereo Retrofit System
Full Stereo and Crew Isolate
Add full stereo capability and crew isolate to your existing SPA-400 / 600 intercom installation with our RES-401 / 601 stereo retrofit system. 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.
Sigtronics RES-401 Stereo Intercom
RES-401 / 601 Stereo Switcher
RES-401 Four Place Stereo Conversion
RES-601 Six Place Stereo Conversion
Size:
4" x 2.9" x 2"
Size:
4" x 2.9" x 2"
Weight RES Unit:
9.8 oz.
Weight RES Unit:
9.8 oz.
Warranty:
5 Years
Warranty:
5 Years
Price:
$129.00
Price:
$144.00
SPA Faceplate
PN 900068
Sigtronics SPA Intercom faceplate
Faceplate PN 900068
SPA Faceplate

Adapts all SPA Intercoms to standard 2.25 inch round instrument hole.

Price: $10.00
Technical Information in PDF
Installation and
Operating
Instructions
SPA-400
Installation and Operating
SPA-400N Installation and Operating
SPA-600 Installation and Operating
SPA-600N Installation and Operating
SPA Panel Template
RES-401 / 601 Installation
RES-401 / 601 Operating
Radio Specific
Installation
Instructions

Figure 4 installation drawing modification for specified radios.

Apollo SL-40 Radio SPA-400 intercom with Apollo SL-40 Radio
Becker AR 3201 Radio SPA-400 intercom with Becker AR 3201 Radio
Becker AR 4201 Radio SPA-400 intercom with Becker AR 4201 Radio
Com 120 Radio SPA-400 intercom with Com 120 Radio
Flightline FL-760 Radio SPA-400 intercom with Flightline FL-760 Radio
Funkwerk ATR833 Radio SPA-400 intercom with Funkwerk ATR833 Radio
Garmin GTR 225 Radio SPA-400 intercom with Garmin GTR 225 Radio
Garmin GNC250/XL Radio SPA-400 intercom with Garmin GNC250/XL Radio
ICOM A-200, A-210 Radios SPA-400 intercom with ICOM A-200, A-210 Radios
ICOM A20, A21 Radio SPA-400 intercom with ICOM A20, A21 Radio
ICOM A3, A6 , A22, A24 Radios SPA-400 intercom with ICOM A3, A6, A22, A24 Radios
King KA 134 Audio Panel SPA-400 intercom with King KA 134 Audio Panel
King KMA 20 Audio Panel SPA-400 intercom with King KMA 20 Audio Panel
King KMA 24 Audio Panel SPA-400 intercom with King KMA 24 Audio Panel
King KY 97A Radio SPA-400 intercom with King KY 97A Radio
King KY 197A Radio SPA-400 intercom with King KY 197A Radio
MGL V6 Radio SPA-400 intercom with MGL V6 Radio
Microair 760 Radio SPA-400 intercom with Microair 760 Radio
Narco COM 810 Radio SPA-400 intercom with Narco COM 810 Radio
Narco COM 810+ Radio SPA-400 intercom with Narco COM 810+ Radio
Narco MK12D Radio SPA-400 intercom with Narco MK12D Radio
Sporty's SP-400 Radio SPA-400 intercom with Sporty's SP-400 Radio
U-174 / U Headset Jacks SPA-400 intercom with U-174 / U Headset Jacks
VAL Com 760 Radio SPA-400 intercom with VAL Com 760 Radio
AUX Audio Input SPA-400 intercom with AUX Audio Input
U-174 / U Headset Jacks SPA-600 intercom with U-174 / U Headset Jacks
U-174 / U Headset Jacks SPA-600N intercom with U-174 / U Headset Jacks
Modification
Dual SPA-400 / 600 Installation
It allows pilot and co-pilot to transmit and receive on the aircraft radio and intercom between themselves, while back passengers can have a separate conversation without interrupting the front two.
SPA-400 / 600 Sidetone Modification Panel Mount Intercom Transmit Sidetone Modification Circuit Board 1528, (SPA-400 S/N 6069006 to Current & SPA-600 S/N 1102528 to Current)
SPA-400 / 600 Sidetone Modification
(Out of Production)
Panel Mount Intercom Transmit Sidetone Modification Circuit Board 1440, (SPA-400 S/N 6053486 to 6069005 & SPA-600 S/N 1101839 to 1102527)
SPA-400
Sidetone Modification

(Out of Production)
Panel Mount Intercom Transmit Sidetone Modification Circuit Board 1092-4, SPA-400 Panel Mount, S/N 61960 to 6053485
SPA-400
Sidetone Modification

(Out of Production)
Panel Mount Intercom Transmit Sidetone Modification Circuit Board 1092-3, SPA-400 Panel Mount, S/N 60975 to 61959
SPA-400
Sidetone Modification

(Out of Production)
Panel Mount Intercom Transmit Sidetone Modification Circuit Board 1092-2, SPA-400 Panel Mount, S/N 60500 to 60974
SPA-400
Sidetone Modification

(Out of Production)
Panel Mount Intercom Transmit Sidetone Modification Circuit Board 1092, SPA-400 Panel Mount, S/N 60001 to 60499.
SPA-400 / 600
ICS Load Modification
This modification is used when a Sigtronics SPA Intercom is connected to a radio or audio panel that has a low impedance headphone output (less than 100 ohms).
SPA-400 / 600
Portable Push-To-Talk Switches
Installation Instructions for use on Sigtronics Panel Mount Intercom Systems
SPA-400 / 600
External Mic Interrupt Modification
This modification applies to a Sigtronics SPA-400 / SPA-600 or ST-400 / ST-600 installations.
SPA-400 / 600
Pilot Isolate Option
Add pilot isolate to a SPA-400 / SPA-600 Intercom.
SPA-400, SPA-400N, SPA-600, and SPA-600N Music Input
Music input options for Sigtronics SPA panel mount intercoms.
Trouble-shooting
Comm Radio Transmit
Instructions designed to assist avionics technicians in diagnosing comm’ radio transmit problems following intercom installation.
Helpful Hints
SPA N
Communicating in Unusually High Noise Environments
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