STW7 Kit Instructions
The STW4 is a 4 zone 2-way Audio Surveillance System for use with all ETS STW1 series microphone /
speakers. It can be used independently for monitoring live audio or with DVRs, tape recorders for recording and
playback.
STW1 Mounting
Locate the STW1 Microphone/Speaker near the area of interest. Do not mount the STW1 near air conditioning
vents, light fixtures or electrical equipment. Try to keep the distance between the STW1 and the STW4 under
1,000 feet.
Cable Run
Run a 22 gauge, 6 conductor shielded cable (1,000 feet maximum length) between the STW1s and the STW4
base station. Keep the cable away from AC power sources, light fixtures and electrical equipment. See
connection diagram.
Adjusting the STW1 Microphone Gain
On the back of the STW1, near the center of the board, is an adjustment pot labeled “Gain.” Use a small flathead
screwdriver and turn t or – for maximum clarity. If the sound at the amplifier is distorted, rotate towards
the – mark (counter clockwise). If the sound is too low, rotate towards the + mark (clockwise). Be careful not to
move the pot too far in either direction.
Setting the STW1 Jumpers
The STW1 Microphone has jumper selectable treble boost and limiter circuits. The treble boost circuit emphasizes
the high frequency sounds that the Microphone picks up. This is useful for improving the sound quality on slow
speed tape recordings (VCR time-lapse recordings). The limiter circuit automatically keeps the STW1’s output at
a relatively constant level. This eliminates the need for the listener to reduce the volume control on the amplifier
when sounds get louder.
Note: Do not use the STW1’s limiter circuit if you are using a tape recorder or other devices that use an
AGC or limiter circuit.
Recommended Jumper settings:
Stand-alone Application
Tape Recorder Application
Limiter “IN”
“OUT”
Treble Boost
“OUT”
“IN”
STW4 Base Station Controls
After connections have been made, apply power to the unit and the system is ready to use. You should hear all
4STW1s audio on the STW4 base station Speaker. Adjust the main “Volume” knot to a comfortable level. You can
set individual channel volumes by the pot under the channel LED.
Sending a message to the STW1s
Select the channels you wish to send a message to (verify that your chosen channel’s green LED
lights are lit.
Then press and hold the “Push To Talk” button on the base station. The yellow LED light indicates that the base
station microphone is sending audio to the selected STW1s.
