Sigtronics SPCC-3 Communication Controllers
OPERATING INSTRUCTIONS
Models SPCC-3, SPCC-3+2, and SPCC-3+2T
INTRODUCTION
The Sigtronics Portable Communications Controller
(SPCC) provides a pilot / observer “mission team”
with the ability to transmit and receive on multiple
transceivers simultaneously and talk to each other
via a voice activated (VOX) intercom. All these features, plus its portability, make it ideal for the airborne or the ground mission team!
Typical Radio Configurations: Use with your aircraft radios (permanently installed or hand-held
models) and two additional “FM” transceivers. A
typical “FM” radio transceiver would be: business
band, police, ham, CB, flight phone, hand-held aircraft, marine, etc. (Some of these are actually AM
radios, however they can be used).
Dual Audio Panel (SPCC-3) capability allows each
headset position to select which radios to transmit
and receive on — independent of the other headset. Each headset position has dual volume controls,
one for radio reception, and the other for their intercom volume level.
Voice Activated Intercom feature allows “handsfree” communication between headsets connected
to the SPCC. Start speaking and the intercom instantly turns on to relay your message clearly to the
other headset. Stop talking and it turns off to reduce
background noise.
Portable design gives flexibility and eliminates expensive installation costs. Especially useful to small
departments that rent or lease. Or if a scheduled
aircraft is down, the SPCC can be used in an alternate aircraft.
igtronics
S
®
Specialists in “SOUND” Management
178 East Arrow Highway, San Dimas, CA 91773 ( 909 ) 305-9399
TECHNICAL HIGHLIGHTS which make the SPCC
unbeatable are:
Fail-Safe Bypass Switch allows the pilot to oper-
ate the aircraft radios even if the unit is turned off.
Automatic Sidetone Generation lets the pilot
and observer hear what the other is transmitting
over the radios.
Separate Transmitter Microphone Gain Ad-
justments adjust the aircraft radio and the two
FM radios independently.
Excellent RF Immunity guarantees clean, clear
transmissions.
Power Requirements: A standard cigarette
lighter socket (11 to 34 VDC) or a battery pack.
Standardized to general aviation headsets and
portable push-to-talk switches. (The unit can also
be wired into permanently installed PTT switches). Helicopter headsets will also work with the
unit if headset plug adapters are used.
APPLICATIONS
CONTROL FUNCTIONS
ON / BYPASS - Power Switch - In “ON” position; sup-
plies power to all SPCC circuits. In “BYPASS” position; disables all unit functions, and connects pilot
directly to the aircraft radios. A fail-safe feature!
VOL - Intercom Volume - Adjusts intercom volume
level.
SQ - Intercom Squelch - Adjusts VOX operation of
the intercom for variations in headset microphones
and background noise levels.
XMIT SELECT - Transmit Select - Used to select
which radio to transmit on.
OFF/A/C, OFF/FM-1, OFF/FM-2 - Receive Select Used to select which radio is heard in any combination. Note: The radio selected by the XMIT SELECT
switch is always heard regardless of the positions of
the receive select switches.
REC VOL - Receive Volume - A general control used
to set the volume level of the aircraft radio(s), and
both FM radios.
A/C RADIO MIC GAIN ADJ - Aircraft Radio Microphone Gain Adjustment - Sets the transmit mic audio level for the aircraft radio(s).
• Airborne Law Enforcement - Small police departments to large organizations like the FBI.
• Civil Air Patrol / Coast Guard - Air search and
rescue operations.
• Medevac Helicopters - Medical emergency aircraft
• Airborne Fire Control
• Forestry Departments
• Wild Life Organizations - Survey and tracking
operations
• TV News Crews
• Airborne Traffic Reporters
• Ground Operations requiring more than one
radio.
• Additional aircraft VHF radio capability - Add
one or two inexpensive hand-held aircraft radios
without installation costs.
FM-1 RADIO MIC GAIN ADJ - FM-1 Radio Microphone Gain Adjustment - Sets the transmit mic audio level for the FM-1 radio.
FM-2 RADIO MIC GAIN ADJ - FM-2 Radio Microphone Gain Adjustment - Sets the transmit mic audio level for the FM-2 radio.
SPCC INSTALLATION
The SPCC requires seven simple connections to put
it into operation. The power cord, the aircraft radio, the FM-1 radio, the FM-2 radio, the push-to-talk
switches, and the headsets must all be connected
for the system to work as designed. But do not fear,
Sigtronics has simplified the connection process, so
it will just take a few moments. Refer to the SPCC
connection drawing Figure 1 on page 3.
1. Power Cord: The four foot power cord with LED
Power Indicator is designed to plug directly into a
standard cigarette lighter socket. The LED indicator will be on if power is available, it will be off if
no power or reversed socket wiring. Note: The
LED shows power available, not SPCC On or Off.
The SPCC will run on 11-34 VDC, so it automati-
page 2
FIGURE 1
FM 1
Cigarette Lighter or
Portable Battery Pack
Aircraft
Headphone
Jack
Aircraft
Hand Mic
Jack
FM 2
Radio
LED Power
Indicator
FM-1 Radio
Interface Cable
A/C Radio Mic Adjust
* Portable
Transmit Switch
* The female jack on portable
push-to-talk switch is not used.
cally adjusts to 12 or 24 volt aircraft. The SPCC can
also be powered by an auxiliary battery pack, if
desired.
2. Aircraft Radio: The mic and headphone cords
on the unit are designed to plug into the mic and
headphone jacks in the panel of the aircraft. If the
aircraft does not have either one of these jacks,
they can be installed by any qualified avionics
technician. If you plan to use the SPCC in a helicopter, please contact Sigtronics for advise on
adapting the general aviation plugs to the helicopter jacks.
3. FM-1 Radio: An interface cable for the FM-1 ra-
dio is needed to connect it to the SPCC. On one
end of the cable will be a five pin connector to
plug into the jack on the top of the SPCC. On the
other end will be whatever is required by your FM
radio. Since virtually any radio can be used and
there is little standardization among manufacturers, no one cable will work for all radio transceivers. Therefore, the FM-1 radio interface cable will
have to be fabricated for your particular radio.
This cable can be supplied to you by Sigtronics
or made up by your radio technician. If you de-
FM-1 Radio
Interface Jack
Transmit Plug
Headphone Plug
Mic Plug
OFF OFF
MIC
XMIT SW
HDPH
OFF
FM-1
FM-2A/C
XMIT SELE CT XMIT SELE CT
REC VO L
INTER COM INTER COM
SQ
Radio
FM-2 Radio
Interface Cable
FM-2 Radio
Interface Jack
FM-1 Radio Mic Adjust
FM-2 Radio Mic Adjust
* Portable
Transmit Switch
OFF OFF
SPCC- 3
ON
BYPASSVOL
SQ VOL
cide to purchase completed interface cables,
Sigtronics has an extensive cable making facility
and can provide you with them at minimum cost.
We will need to know what length cable you require and the manufacturer and model number
of the radios you wish to use.
If you would rather have your radio technician
make the cables, the FM radio interface cable
connector pin assignments and some typical
cable wiring examples are located on page 7.
Two five pin connector plugs are supplied with
each SPCC unit for this purpose. You will also
need the radio mating connectors and connection schematics or hook-up drawings for
your particular FM radios. These can usually
be obtained from the radio manufacturer. 4.
FM-2 Radio: Same as step 3.
5. Push-to-Talk Switches: In order for pilot and
observer to transmit on their selected radios,
they will each need a push-to-talk (PTT) switch.
The SPCC is compatible with all standard general
aviation type portable push-to-talk switches. The
male plug on the PTT switches plug directly into
the XMIT SW jacks of the SPCC unit. If your PTT
FM-1 FM-2A/C
REC VO L
OFF
MIC
XMIT SW
HDPH
Mic Plug
Transmit Plug
Headphone Plug
page 3
switches also have a female jack, it is not used.
The pilot should strap the switch end of his portable PTT switch to the yoke or stick of the aircraft.
The observer’s PTT can similarly be strapped to
the co-pilot controls or operated as a hand-held
switch. Various types of push-to-talk switches are
available from Sigtronics, including one that does
not have the female jack.
If you already have permanently wired push-to-
talk switches in the aircraft, and wish to use them
with the SPCC instead of the portable type, then
wiring modifications will have to be made to the
aircraft. Again, your avionics technician should
be able to do this for you.
to-talk switch and headset. All other intercom
functions should be inoperable in the BYPASS
mode.
2. Intercom operation and adjustment can be
performed by the following procedure:
A. First set the ON/BYPASS switch to the “ON”
position and turn both REC VOL controls all
the way down (counterclockwise).
B. Turn both intercom volume controls to the 9
o’clock position and both squelch controls all
the way up (clockwise). Notice the intercom
is now continually activated and you should
be able to talk between headsets.
6. Headset Hookup: All standard general aviation
headsets are compatible with the SPCC unit. Helicopter type headsets can also be used if adapter
cables are used. (Sigtronics manufactures cables
that adapt the helicopter plugs to general aviation plugs).
Plug the microphone and headphone plugs
on the headsets into the jacks labeled MIC and
HDPH, on the front panel of the SPCC. Put on
the headset, and position the boom mic close
to the mouth, as is the practice with hand-held
microphones. Voice clarity is best when the mic is
about 1/4” away and slightly off center from the
lips. Turn headset volume control(s), if any, all the
way up.
INITIAL SYSTEM CHECK-OUT
The following System Check-Out will provide you
with a “personalized” system. Perform the next few
steps while on the ground to assure that all functions on the unit and radios are set to your personal
hearing and speaking comfort.
CAUTION - As is standard practice with all aircraft
equipment, be sure that the radio(s) and the SPCC
are turned OFF when you start up the aircraft engine.
C. To adjust the intercom squelch controls for
voice activated operation (VOX), it is helpful
to have some background noise present. It
may also be necessary to turn up the intercom volume controls. Turn both intercom
squelch controls all the way counterclockwise. Now, without speaking, rotate one
of the squelch controls clockwise until you
hear the background noise in your headset.
Next, using that same control, rotate counterclockwise small, incremental amounts
until the background noise disappears. (This
procedure is necessary because the squelch
is a “fast on, slow off” system). That squelch
control is now set.
D. Adjust the other intercom squelch control
similarly by turning it clockwise until you hear
background noise. Rotate counterclockwise
incremental amounts until the background
noise disappears.
Small adjustments may be necessary if air-
craft background noise changes significantly
- such as from idle to full power.
3. Radio Selection of both the aircraft and the FM
radios is provided by two switches.
1. To assure that the aircraft radios, and pilot’s
headset and PTT switch are connected and
functioning properly, put ON/BYPASS switch
into “BYPASS” position. Then turn on the aircraft radios, and verify that the pilot can hear
the radios and can transmit using his push-
A. XMIT SELECT determines the primary radio
you wish to transmit and receive on.
B. OFF/A/C, OFF/FM-1, OFF/FM-2 selects which
additional radio or radios you wish to receive
in your headset.
page 4
4. Receive Volume Controls (REC VOL) are general
volume controls, meant to provide overall listening level for all three radios simultaneously
- A/C, FM-1, and FM-2. Finite volume adjustments of any individual radio should be done
by altering the radio volume control at the radio itself.
SYSTEM OPERATION
Once the radios are selected, pilot or observer can
transmit at any time simply by pressing their PTT
switch. When one position transmits, several things
take place automatically to the transmitting side of
the SPCC:
• The intercom between the two positions is
turned off.
• The receive audio of the radios not selected by
the XMIT SELECT switch are muted, regardless of
the position of the receive select switches.
• The selected radio is put into transmit mode.
• The headset microphone audio (your voice) is
sent to the selected transmitter.
they can also transmit on the same radio transmitter. If, for example, the observer is talking on one
of the radios, the pilot can jump right in and add to
the conversation simply by pressing his PTT switch.
Both voices will be heard by the receiving station.
TRANSMIT MICROPHONE GAIN ADJUSTMENTS
Transmit microphone gain adjustments for both FM
and the aircraft radios are provided through three
small holes on the top of the SPCC unit. These adjustments set the microphone audio level going to
the radios during transmit. Adjustment should be
made only if the outgoing radio transmissions are
reported as weak or garbled. The Aircraft Radio Mic
Gain Adjustment is set at the factory for standard
aircraft radios and should not need any adjustment.
The two FM Radio Mic Gain Adjustments, however,
will more than likely need to be initially set to your
particular FM radios. These levels, once set, should
never need adjustment again unless, of course, the
type of FM radios used are changed. The following
simple procedures take you through the adjustment of the FM and A/C mic gain levels. If desired,
a qualified radio technician can do this for you.
• Sidetone is generated and sent to your head-
phones.*
* Sidetone is a portion of the transmitted voice signal sent back into your headset, so that you can hear
what you are saying while transmitting. The RECeive
VOLume control adjusts the volume level of the sidetone that you hear in your headset.
The non-transmitting side is not affected (except
for intercom) when the other side transmits. The
non-transmitting side can monitor the transmissions of the other side by simply selecting the same
radio on his side of the SPCC. Of course, when the
PTT switch is released, (stop transmitting) all functions return to normal, instantly and automatically.
Simultaneous Transmit is the most attractive and
powerful feature of the SPCC. Both pilot and observer can transmit at the same time - either on
separate radios or on the same radio transmitter!
When on different radios, the pilot and observer
will not interfere with each other’s communications.
For example, the pilot can talk to air traffic control
while the observer talks on one of the FM radios to
the ground crew, or vice versa. On the other hand,
FM-1 & FM-2 Radio Mic Gain Adjustment can be
made through the middle and right hole respectively, just to the right of the FM-1 radio interface
connector with a small, flat bladed screwdriver.
The basic adjustment concept for both FM radios
is simple. On a one at a time basis, you will be setting the level and clarity of outgoing transmissions
of the FM radios, when they are hooked up through
the SPCC, to match or exceed that of transmissions
on the radios when they are not connected to the
SPCC. To do this, you will need to transmit and receive on the FM radios to a remote station. Arrange
to have someone nearby with radios compatible to
the FM radios you are using with the SPCC. Then
first for FM-1 . . .
1. Set the ON/BYPASS switch to the “BYPASS”
position and connect the SPCC up to power, as
normal. Plug in the observer’s PTT switch and
headset. (It is not necessary to connect the A/C
radios or the pilot’s headset or PTT switch for this
adjustment.) Do not connect the FM-1 radio to
the SPCC at this time. Set the observer’s XMIT
SELECT switch to “FM-1”, and all three receive
select switches to “OFF”.
page 5
2. Set the SPCC aside for a moment. With the FM-1
radio disconnected from the SPCC, transmit as
normal, on the FM-1 radio, to the remote station. Transmit long enough so that the receiving
station can get “calibrated” to your transmission
(voice) level.
3. Connect the FM-1 radio to the SPCC as normal
with the FM-1 interface cable. Put on the observer’s headset and turn the SPCC “ON”. Verify FM-1
radio reception. If OK, use observer’s PTT to transmit to your receiving party. If receiving station
reports weak transmission, use the screwdriver to
turn the FM-1 MIKE GAIN ADJ clockwise a small
amount. If they report garbled or broken transmissions, turn the FM-1 MIKE GAIN ADJ counter-
clockwise a small amount. Repeat as necessary
until the receiving party reports that transmissions through the SPCC sound as good or better
then when the FM-1 radio is used separate from
the SPCC. That’s all that’s required for FM-1.
4. To set the FM-2 Radio Mic Gain Adjustment first set
the observer’s XMIT SELECT switch to “FM-2”.
5. Take off the headset and set the SPCC aside for a
moment. With the FM-2 radio disconnected from
the SPCC, transmit as normal, on the FM-2 radio,
to the remote station. Transmit long enough so
that the receiving station can get “calibrated” to
your transmission (voice) level.
The A/C Radio Mic Gain Adjustment is located to
the left of the FM-1 radio interface connector. Again,
the A/C Mic Gain Adjustment, in most cases, will not
have to be changed from its original factory setting.
If however, your aircraft radio transmissions through
the SPCC are reported as weak or garbled, you will
need to reset this level. The adjustment procedure
is similar to that of the FM mic gain adjustment
above. You can, however, use the “BYPASS” mode
of the SPCC to aid in the adjustment. Arrange to
have someone with an aircraft radio nearby with
whom you can transmit and receive. Then, proceed
as follows:
1. Set the ON/BYPASS switch to the “BYPASS” posi-
tion and connect the unit as normal to power and
aircraft radios. Plug in the pilot’s headset and PTT
switch into the jacks on the left side of the SPCC.
(The FM radios and observer’s headsets and PTT
switches are not needed for this adjustment.) On
the pilot’s side of the SPCC, set the XMIT SELECT
switch to the “A/C” position, and all three receive
select switches to “OFF”.
2. Put on the pilot’s headset. Transmit and receive to
your nearby station, using the pilot’s PTT switch
and headset, as described in the Initial System
Check-Out section on page 8. Verify good transmission and reception. In this mode you are bypassing the SPCC and verifying the clarity of the
aircraft radios.
6. Connect the FM-2 radio to the SPCC as normal
with the FM-2 interface cable. Put back on the
observer’s headset. Verify FM-2 radio reception.
If OK, use observer’s PTT to transmit to your receiving party. If receiving station reports weak
transmission, use the screwdriver to turn the
FM-2 MIKE GAIN ADJ clockwise a small amount.
If they report garbled or broken transmissions,
turn the FM-2 MIKE GAIN ADJ counterclockwise
a small amount. Repeat as necessary until the receiving party reports that transmissions through
the SPCC sound as good or better then when the
FM-2 radio is used separate from the SPCC. That’s
all there is to it!
page 6
3. If radios check out OK, then turn the ON/BYPASS
switch to the “ON” position. Verify aircraft radio
reception. If OK, use the pilot’s PTT to transmit
to your receiving party. If the receiving station
reports weak transmissions, use the screwdriver
to turn the A/C MIKE GAIN ADJ clockwise a small
amount. If they report garbled or broken transmissions, turn the A/C MIKE GAIN ADJ counterclockwise a small amount. Repeat as necessary
until the receiving party reports that transmissions with the SPCC turned “ON” sound as good
as that when the ON/BYPASS switch is “BYPASS”
mode.
12435
12345
12435
FM RADIO INTERFACE CABLE WIRING
FM Radio Interface Cable Connector Pin Assignments for both FM-1 and FM-2 Connectors
FIGURE 2
Male five pin connector shown from solder side:
Pin Function
1 Mic audio output to FM radio
3 Receive audio input from FM radio
4 FM radio ground
Transmit key output to FM radio (Normally
2,5
open relay contacts closed during FM radio transmit)
FM Radio Interface Cable Wiring Examples
The following are some examples of possible wiring schemes for the FM-1 and FM-2 interface cables.
Only the FM radio functions are shown for the
FM radio end of the interface cable, because the
connector(s) used by radio manufacturers varies
widely. You will have to consult the radio manual
or manufacturer for the connector(s) used and pin
assignments for your particular FM radios. Also,
Sigtronics has extensive radio interface experience
and can assist in any question you might have concerning this or any other aspect of the SPCC. Of
course, Sigtronics can build the FM interface cables
for you to your specifications, if desired.
Figure 3 shows the most common of such cables
with its “high level mic input” and standard “ground
to key” interface. This cable will work with most
standard police, fire, and business band radios as
well as aircraft type radios.
1
PLUG END SOLDER END
3
4
5
2
FIGURE 3
SPCC
Pin #
FIGURE 4
SPCC
Pin #
33K *
1K *
* Use 1/8 or 1/4 watt resistors
3
5
FM RADIO
Mic Audio Input
Ground
Headphone Audio
Outpu t
Transmit Key Input
FM RADIO
Mic Audio Input
Ground
Headphone Audio
Outpu t
Transmit Key Input
1
4
2
Figure 4 is similar to Figure 3 but is used for radios
requiring a low level mic input such as marine type
radios.
SPCC
Pin #
FIGURE 5
FM RADIO
Figure 5 shows typical cable wiring for radios that
sense the presence of mic current to transmit. Most
ICOM hand-held radios are set-up this way.
page 7
Headphone Audio
Outpu t
Ground
Transmit Key Input
SPCC-3+2
THREE YEAR WARRANTY
The +2 option allows for one or two additional
headset positions to be added to the standard SPCC
for intercom. This is ideal for training or if you need
additional spotters or observers along on your missions. A small remote satellite unit is provided that
connects to the main SPCC unit. This satellite unit
comes standard with two sets of headset jacks and
a four foot cable so that it can be placed in the back
seat of the aircraft for convenience. The satellite unit
is also detachable for those times you only need
two positions. As well as full VOX intercom, the back
two headsets also hear the radio(s) selected by the
front observer’s position. Similarly, the radio receive
and intercom volume and squelch controls on the
observer’s panel also control the corresponding
levels for the back two positions. These back two
positions cannot transmit on any of the radios and
their microphones are silenced whenever the observer presses his PTT switch to transmit. They will,
however, hear what the observer is transmitting. All
other functions for the pilot and observer positions
operate just as with non +2 units.
SPCC-3+2T
The +2T option operates just like +2 option (See
above) except for one exception. The back two positions can transmit. They will only transmit on the
radio that is selected on the observers side of the
SPCC. Two additional jacks are provided on the satellite unit for portable PTT switches. One for each
back position.
Every Sigtronics’ product has been carefully inspected before shipment. We guarantee to correct
any defect caused by faulty material or workmanship free of charge to the user who originally purchased the product for a period of three years from
the original purchase date. Our obligation assumed
under this guarantee is limited to the replacing of
any part or parts which prove to our satisfaction,
upon examination to have been defective, and
which have not been misused or carelessly handled. The complete unit must be returned to our
factory, transportation charges prepaid. We reserve
the right to decline responsibility where repairs or
replacements have been made or attempted by
others. No other guarantee, written or verbal, on
our products is authorized by us.
Repairs required due to abuse, misuse, damage or
normal service beyond the warranty period will be
subject to normal service charges.
To expedite factory service work, write Sigtronics’
Service Department and explain the problem. All
correspondence relative to service work should include model and serial number. Frequently problems can be resolved by phone. Should you wish
to call, our number is (909)305-9399.
SIGTRONICS CORPORATION
178 East Arrow Highway
San Dimas, CA 91773
Phone: 909-305-9399
SPCC-3 SPECIFICATIONS
Input Voltage: ......................... 11-34 VDC
Nominal Current: .................... 0.08 Amps
Maximum Current: ................0.16 Amps
Weight: ...................................... 22 oz.
Size:............................................. 3.75 x 6.25 x 2.5 inches
A/C Interface Cord length: 4 feet each
FAX: 909-305-9499
Web: www.sigtronics.com
1-23-2015 spcc3i_and_o.pdf
P/N 700060
page 8
Loading...