Model 888TT User Guide
©
2004, Shure Incorporated
27A6003B (Rev. 2)
Printed in U.S.A.
GENERAL DESCRIPTION
The 888TT handheld, amplified, noise-canceling DTMF com-
munications microphone is FAA Certified for aircraft application
(TSO-C58a). In addition to its extremely clear transmission, even
in noisy environments, the 888TT has very low sensitivity to hum
pickup and low susceptibility to radio frequency interference.
Audio and DTMF levels can be independently adjusted with the
supplied screwdriver to match the transmitter input gain. These
protected external controls prevent accidental changes by the user
while allowing adjustments without having to disassemble the mi-
crophone case.
The illuminated keypad is made of tough silicone rubber, with
durable printed characters that will last the life of the microphone.
The keypad is backlit by red LEDs, easily visible during night oper-
ation, minimizing eye readjustment for night vision.
The 888TT may be used with most currently available aircraft
radios. For convenience, all microphone and signaling functions,
including keypad illumination, are powered directly from the micro-
phone input circuit of most transmitters, reducing the need for
equipment modification. A five-conductor MODULINK
®
cable (sold
separately) connects the modular telephone-type socket of the
888TT to most aircraft radios using a PJ-068 plug. This cable can
be instantly changed or replaced without soldering.
The 888TT is ergonomical, fitting naturally and comfortably in
the hand. The voice-entry port is at the top of the microphone body
for simple, natural transmitting. The microphone is not affected by
heat or humidity, and the rugged ARMO-DUR
®
case is immune to
oil, grease, most fumes and solvents, salt spray, sun, rust and cor-
rosion. The 888TT is outstanding in its ability to withstand mechan-
ical shocks and vibration. Its Million-Cycle Plus™ leaf-type switch
is a double-pole, single-throw type that resists the effects of severe
operating conditions and constant use. It has nickel-silver blades
with palladium alloy contacts for reliable oxidation-free operation.
The microphone is supplied with output levels factory preset to
meet TSO-C58a requirements. Adjustments should be made only
by an FAA Approved Service Facility or the Shure Service Depart-
ment.
The 888TT is supplied with a small screwdriver for releasing the
modular-plug microphone cable from the case and for adjusting
the microphone amplifier gain and DTMF level. A mounting loop is
supplied affixed to the microphone, and mounting brackets for at-
taching to radio equipment or other surfaces are available in quan-
tities of three as Shure RK6MB.
PART OF A COMPLETE LINE
The 888TT is part of a full line of mobile microphones, circuitry
products and related accessories.
For a complete listing, contact your Shure Representative or vis-
it www.shure.com.
APPLICATIONS
•
Aerospace
FEATURES
•
FAA CERTIFIED FOR AIRCRAFT USE
•
DETACHABLE MODULINK
®
MODULAR PLUG COIL CORD
WITH PJ-068 AIRCRAFT-RADIO PLUG OR A4M TYPE
CONNECTOR
•
NOISE-CANCELING WITH FREQUENCY RESPONSE
TAILORED FOR OPTIMUM INTELLIGIBILITY
•
TOP-TALK SOUND CHANNEL™ FOR CLEAR VOICE INPUT,
EASY HANDLING
•
BUILT-IN TRANSISTOR AMPLIFIER POWERED BY
CARBON-MICROPHONE-TYPE CIRCUIT
•
ILLUMINATED KEYPAD WITH POSITIVE TACTILE
CONFIRMATION AND AUDIBLE VERIFICATION TONES
•
SIMPLE EASY-TO-USE CONTINUOUS-TONE DIALING
•
SCREWDRIVER ACCESSIBLE DTMF LEVEL ADJUSTMENT,
INDEPENDENT OF MICROPHONE GAIN SETTING
•
LOW SENSITIVITY TO HUM AND RF INTERFERENCE
•
RUGGED MILLION-CYCLE PLUS™ LEAF-TYPE SWITCH
STANDS UP UNDER SEVERE ENVIRONMENTS AND
CONSTANT USE
•
HIGH IMPACT ARMO-DUR
®
CASE, STRONG,
LIGHTWEIGHT, COMFORTABLE TO THE TOUCH IN HOT
OR COLD ENVIRONMENTS
•
RUGGED AND DEPENDABLE UNDER ALL OPERATING
CONDITIONS
SET-UP
The 888TT is equipped with a hang-up loop and a rear-case
hang-up button for use with a mounting bracket on associated
equipment.
Heavy-duty chrome-plated mounting brackets are available in
quantities of three as Shure Part No. RK6MB.
CONNECTIONS
To attach the cable to the 888TT, insert the modular telephone-
type plug in the microphone jack until it locks.To remove the cable
from the microphone, insert the small screwdriver supplied with the
888TT in case hole “A” just above the cable jack (see Figure 4) to
unlock the plug and withdraw the plug from the jack. Microphone
connector wiring is shown in the table below. The ALM-88 cable is
wired at the microphone connector as shown in Figure 3.
Table 1. Microphone Connector Wiring
Pin Color
Function
Pin
Color Function
1
N.C.
5
Black
PTT
Switch
Ground
2
White
Dc Bias (+),
Audio Out
6
Red
Audio Out
(Ac
coupled)
3
Yellow PTT Switch
7
Drain
Ground
4
Blue
NC
8
N.C.
®Shure, MODULINK, and ARMO-DUR are registered trademarks of Shure,
Incorporated.™ Million-Cycle Plus and Top-talk Sound Channel are trademarks of
Shure Incorporated. All other trademarks are the property of their respective owners.
