Introduction
The Audio-Technica System 9 is a four-channel frequency-agile VHF wireless system designed for reliable performance and ease of use. It offers clear, natural sound quality and features stackable, contemporary styling. The system is available in various configurations, including handheld, headworn, guitar, and lavalier microphone systems.
The System 9 offers four compatible, user-switchable channels within one of four available VHF frequencies: 169.505 MHz, 170.245 MHz, 171.045 MHz, and 171.905 MHz. Each system includes a receiver and either a body-pack transmitter (ATW-901a series) or a handheld microphone/transmitter (ATW-902a).
The ATW-901a UniPak body-pack transmitter systems can be pre-packaged with an AT-GCW guitar cable (/G), a PRO 8HECW headworn microphone (/H), or a lavalier microphone (/L). Various Audio-Technica microphones and cables are available separately.
The ATW-R900a receiver features a switching power supply that automatically adapts to mains voltage. The ATW-T901a UniPak body-pack transmitter supports both high-impedance instrument inputs and low-impedance microphone inputs. The ATW-T902a handheld transmitter includes a unidirectional dynamic microphone element. Both transmitter types use internal AA batteries and have Power/Mute switches and input Trim (level) adjustments.
Compliance Information: This device complies with FCC Rules Part 15 and Industry Canada license-exempt RSS standards. Operation is subject to conditions that prevent harmful interference. A copy of the declaration of conformity is available at www.audio-technica.com.
Notice to Individuals with Implanted Cardiac Pacemakers or AICD Devices: Sources of RF energy may interfere with implanted devices. While wireless microphone transmitters have low power output, it is suggested to keep body-pack transmitters away from medical devices. Any disruption typically ceases when the RF source is turned off. Consult your physician or medical-device provider for questions.
Packaging Note: System 9 packaging is designed to accommodate all system versions, so some compartments may be intentionally left empty.
Receiver Installation
Location
For optimal performance, position the receiver at least 3 feet (1 meter) above the ground and 3 feet (1 meter) away from walls or metal surfaces to minimize reflections. Keep receiver antennas away from noise sources like digital equipment, motors, automobiles, and neon lights. For multi-channel systems, position receivers at least 3 feet (1 meter) apart and keep transmitters at least 6 feet (2 meters) from receivers.
Output Connections
The receiver has two audio outputs on the back panel: balanced and unbalanced. Use shielded audio cable. Connect the 1/4" unbalanced output to a mixer/amplifier's unbalanced input. Connect the XLR balanced output to a mixer/amplifier's balanced microphone-level input.
Power Connection
Connect the included AC power adapter's DC plug to the receiver's DC power input jack. Use the cord hook to secure the cable. Plug the adapter into a standard 120V, 60Hz AC power outlet. The receiver has no power switch; it is energized when plugged in. Unplug the power supply when the system is not in use.
Antennas
The receiver features a "dipole" antenna system. Position the two antennas at a 90° angle in a "V" shape, or position one antenna vertically and the other horizontally in an "L" shape (refer to Figure A). Extend antennas to their full 15" (38 cm) length. The antenna elements can be swiveled but not rotated in a screwing motion to avoid damage. For best results, ensure the antennas have a direct line-of-sight to the transmitter.
Receiver Controls and Functions
Front Panel Controls (Figure A)
- ANTENNAS: Position the "signal" (1a) and "ground" (1b) antennas as shown. Fully extend them.
- RF INDICATOR: Illuminates to indicate transmitter signal presence.
- CHANNEL SELECT BUTTON: A soft-touch button to select the operating channel.
- CHANNEL INDICATOR LIGHTS: LEDs show the selected channel. A light also indicates power is applied.
- AF PEAK INDICATOR: Illuminates when audio distortion occurs at maximum modulation.
Rear Panel Controls (Figure B)
- SQUELCH CONTROL: Adjusts the noise-muting circuit level.
- VOLUME CONTROL: Adjusts the audio output level for the 1/4" and XLRM jacks.
- UNBALANCED AUDIO OUTPUT JACK: A 1/4" TS (mono) jack for unbalanced connections.
- BALANCED AUDIO OUTPUT JACK: An XLRM connector for balanced microphone-level connections.
- POWER INPUT JACK: Connects the AC adapter.
- CORD HOOK: Secures the power cord.
Transmitter Setup Controls and Functions
Battery Selection and Installation
Two AA alkaline batteries are recommended. Observe polarity markings when inserting batteries into the compartment.
Handheld Transmitter
Battery Installation
Unscrew the lower body cover below the ball-screen to access the battery compartment. Insert two AA alkaline batteries, observing polarity. Screw the body back together, avoiding overtightening.
Battery Condition Indicator
After battery installation, press and hold the Power/Mute switch. The indicator LED should turn green. If it doesn't light, batteries may be installed incorrectly or dead. A flashing LED indicates a low-battery condition.
Channel Selection
Before powering on, use DIP Switches 1 and 2 inside the transmitter to select the desired channel. Access them by unscrewing the lower body cover. Set switches to "up" or "down" according to the desired channel configuration (Channel 1: 1&2 up; Channel 2: 1 up, 2 down; Channel 3: 1 down, 2 up; Channel 4: 1&2 down). Replace the cover.
Mute Function
A slight touch of the Power/Mute switch toggles between muted (red LED) and unmuted (green LED) operation. Muted operation transmits RF but no audio.
UniPak Transmitter
Battery Installation
Slide off the battery cover. Insert two fresh AA alkaline batteries, observing polarity. Replace the cover.
Power/Mute/Battery Indicator
After battery installation, press and hold the power button until the indicator LED turns green. If the LED does not light, batteries may be installed incorrectly or dead. A flashing LED indicates a low-battery condition.
Channel Selection
Before powering on, use DIP Switches 1 and 2 inside the transmitter (accessed by sliding off the battery cover) to select the desired channel. Set switches to "up" or "down" according to the desired channel configuration (Channel 1: 1&2 up; Channel 2: 1 up, 2 down; Channel 3: 1 down, 2 up; Channel 4: 1&2 down). Replace the cover.
Mute Function
A slight touch of the Power/Mute button toggles between muted (red LED) and unmuted (green LED) operation. Muted operation transmits RF but no audio.
Input Connection
Connect an audio input device (microphone or guitar cable) to the audio input connector on the top of the transmitter. Specific Audio-Technica microphones and cables with UniPak connectors are available separately.
Antenna
The UniPak transmitter has a permanently attached flexible antenna. Allow it to hang freely and at full length for best results. Experiment with transmitter position if the signal is marginal. Do not attempt to remove, replace, or change the antenna length.
System Operation
Startup Procedure
- Turn down the receiver volume control and mixer/amplifier levels.
- Plug the receiver's power supply into an AC outlet. The green Power indicator will light.
- Press the receiver's Channel Select Button repeatedly until the desired channel is displayed.
- Set the transmitter's DIP switches to match the selected receiver channel.
- Turn on the transmitter. The receiver's amber RF signal indicator should light.
Transmitter Operation
When the transmitter is switched on, the receiver's RF indicator lights. The Power/Mute switch toggles between muted (red LED) and unmuted (green LED) operation. Muted operation transmits RF only; unmuted operation transmits RF and audio. Excessive audio input may cause the receiver's red AF Peak indicator to light.
Receiver Volume
For typical use, set the receiver's volume control to maximum. Adjust overall system audio gain at the mixer or amplifier.
Input Level Adjustment
Input trimmer controls in the transmitters optimize performance for specific microphones or guitars and adjust for varying acoustic input levels.
Adjusting Input Level - UniPak Transmitter
- Remove the battery cover and locate the "MIC" (Mic Trimmer) and "INST" (Instrument Trimmer) controls.
- Turn both controls fully counterclockwise (to "L").
- For Microphone: Turn the "MIC" control fully clockwise (to "H"). Speak/sing into the microphone at typical loud levels. If the receiver's AF Peak indicator lights, turn the "MIC" control slightly counterclockwise until the indicator no longer lights.
- For Guitar/Instrument: Turn the "INST" control fully clockwise (to "H"). Play at typical loud levels. If the receiver's AF Peak indicator lights, turn the "INST" control slightly counterclockwise until the indicator no longer lights.
- Return the screwdriver to its clip and replace the battery cover.
Adjusting Input Level - Handheld Transmitter
- Unscrew the lower body cover to access the "LEVEL" (Gain Trimmer) control.
- Turn the "LEVEL" control fully clockwise (to "H").
- Speak/sing into the microphone at typical loud levels. If the receiver's AF Peak indicator lights, turn the "LEVEL" control slightly counterclockwise until the indicator no longer lights.
- Return the screwdriver to its clip and secure the body cover.
Caution: Use only the supplied screwdriver for trimmer adjustments. Do not force controls beyond their normal range (approx. 190° rotation).
Ten Tips to Obtain the Best Results
- Use only fresh alkaline batteries.
- Position the receiver for clear line-of-sight to the transmitter.
- Keep transmitter and receiver as close as practical, but not less than 6 feet (2 meters).
- Keep receiver antennas at least 3 feet (1 meter) from other receivers or antennas.
- Keep receiver antennas away from metal objects.
- A receiver cannot simultaneously receive signals from two transmitters on the same frequency.
- For UniPak transmitters, set unused "MIC" or "INST" input controls to minimum.
- Adjust receiver output level so that the highest sound pressure level does not cause mixer input overload, allowing mixer controls to operate in their normal range. This optimizes the signal-to-noise ratio.
- Turn transmitters off when not in use. Remove batteries if storing for extended periods.
- Unplug the receiver from the AC outlet when not in use.
Frequencies and Specifications
System Operating Frequencies
The System 9 operates on four switch-selected frequencies. These can be combined for up to 4 simultaneous operating channels. Frequencies are generally usable in the USA and Canada, but local regulations should be checked for availability outside these regions.
System 9 Operating Frequencies/Channels
| Channel | Frequency - MHz | Frequency Code |
|---|---|---|
| 1 | 169.505 | T2 |
| 2 | 170.245 | T3 |
| 3 | 171.045 | T5 |
| 4 | 171.905 | T8 |
RF Interference
Wireless frequencies are shared with other radio services. Wireless microphone operations are unprotected from interference from other licensed operations. If interference is received, the wireless microphone must cease operation. For assistance, contact your dealer or Audio-Technica U.S. Extensive wireless information is available at www.audio-technica.com.
System Information Recording
For future reference, record your system's serial numbers here. Serial numbers are located inside the transmitter battery compartment and on the bottom of the receiver.
- Receiver Model: ATW-R900a
- Receiver Serial Number: ____________________
- Transmitter Model: ATW-T90 (1a or 2a)
- Transmitter Serial Number: ____________________
Specifications
| OVERALL SYSTEM | UNIPAK® TRANSMITTER | HANDHELD TRANSMITTER | |
|---|---|---|---|
| Operating Frequencies | VHF highband, 169 MHz to 172 MHz | ||
| Modulation Mode | FM | ||
| Maximum Deviation | ±10 kHz | ||
| Dynamic Range | ≥90 dB (A-weighted), typical | ||
| Total Harmonic Distortion | <1.5% (at 1 kHz, ±10 kHz deviation) | ||
| Operating Range | 200' (60 m) typical (open range, no interfering signals) | ||
| Operating Temperature Range | 40° F (4° C) to 110° F (43° C) (Battery performance may be reduced at very low temperatures) | ||
| Frequency Response | 80 Hz to 13 kHz | ||
| RECEIVER | |||
| Receiving System | Non-diversity, single-channel, dual antenna system | ||
| Image Rejection | 50 dB minimum | ||
| RF Sensitivity | 20 dBuV at 60 dB S/N ratio (50 ohms termination) | ||
| Normal Output Level (XLR, balanced) | 350 mV (1 kHz modulation, 10 kHz deviation, 100k ohm load) | ||
| Normal Output Level (1/4", unbalanced) | 700 mV (1 kHz modulation, 10 kHz deviation, 100k ohm load) | ||
| Power Supply | 100-240V AC (50/60 Hz) to 12V DC .5A (center positive) switched mode external power supply | ||
| Dimensions | 7.48" (190.0 mm) W x 1.82" (46.2 mm) H x 5.06" (128.5 mm) D | 2.76" (70.2 mm) W x 4.08" (103.7 mm) H x 0.98" (24.9 mm) D | 9.91" (251.8 mm) long, 2.11" (53.5 mm) diameter |
| Net Weight | 12.0 oz (337 grams) | 2.8 oz (80.0 grams) | 9.2 oz (260 grams) |
| Accessory Included | Power supply | RF Output Power: 10 mW Spurious Emissions: Following federal and national regulations Input Connection: Four-pin Locking Connector (Pin 1: GND, Pin 2: INST INPUT, Pin 3: MIC INPUT, Pin 4: DC BIAS +9V) Batteries (not included): Two 1.5V AA Battery Life: 8 hours (alkaline) (Depending on battery type and use pattern) | RF Output Power: 10 mW Spurious Emissions: Following federal and national regulations Batteries (not included): Two 1.5V AA Battery Life: 8 hours (alkaline) (Depending on battery type and use pattern) |
| Accessory Included: AT8456a Quiet-Flex™ stand clamp |
Note: In the interest of standards development, Audio-Technica U.S. offers full details on its test methods to other industry professionals on request.
Environmental Information
To reduce environmental impact, product information is available online at www.audio-technica.com in a selection of languages, including English, French, Spanish, Portuguese, Italian, German, Dutch, Chinese, and Korean.
