Bosch Security Systems M522 Users manual

Preliminary Operating Instructions
Telex Model ST-300 Auditory Assistance Transmitter

Carefully unpack your Auditory Assistance Transmitter. If there is any damage or
shortages, please refer to the “Warranty Service Information”.

Set-up Instructions:

Power: Power will be received from the supplied “wall cube”. Before applying
power, it is suggested that all input cords be plugged in and the antenna be screwed
onto the transmitter. Insert the cord plug into the transmitter before plugging in the
wall cube. The wall cube normally supplied is for 120 V AC, 60 Hz use only.

Transmitter Location: Select a suitable location for the transmitter. Try to keep a
clear, unobstructed path between the transmitter and the receiver. The transmitter
should not be located near metallic objects such as building structures and file
cabinets. Locating the transmitter on top of a file cabinet is OK. Avoid high heat sources
such as radiators .

Antenna: The transmitter uses a special “reverse” RF connector on the model ST-300.
This is intentional and is designed to comply with FCC Part 15 Rules. The antenna
supplied should be the only antenna used with the ST-300. The antenna is designed to
operate in the vertical position.

Audio Input: One or both of the audio input connections can be used at the same time. A
single modulation limiter serves both inputs. If either input is not used, that input should
be “turned off”. Unbalanced devices should be plugged into the ¼ in. (quarter inch)
Unbalanced Audio input jack located on the rear panel. Tip is “hot” and the barrel is
ground. Balanced devices should be plugged into the Balanced Audio “XLR” jack
located on the rear panel. Pin 1 is Common (or ground), Pin 2 is audio input, Pin 3 is
audio input. See operating instructions for additional information.

E.D.R. audio: The Telex ST-300 Transmitter is equipped with E.D.R., Enhanced
Dynamic Range (companded) audio. This mode greatly improves the Audio Signal
to Noise Ratio when the ST-400 is used with the Telex Model SR-400 receiver. The
E.D.R. mode must be selected on the transmitter and receiver to be effective. Also,
The E.D.R. Mode must be de-selected if the ST-300 is used with more economical
receivers such as the Telex SR-50 receiver. See Operating Instructions for further
information.

Telex ST-300 Transmitter Page 2

Frequency/Channel Considerations: As with any radio device, interference can occur at
any time. The frequencies offered are shared with other legitimate users. Check the
frequency/channel with the matching receiver to see if any interference is present. If
interference is present, choose a different channel. The severity of interference varies with
location and distance to the interfering station. If the interference is weak on all channels,
this is probably acceptable since your transmitter will cover the interference and is unlikely
to interfere with other users. Multiple Channel Systems require other considerations but
each channel should be checked as above. For best results, locate each transmitter in the
area it is to service, and as far apart as possible.

Transmitter Operation: Turn the Monitor control down (counter-clockwise). Now that you
have checked all of the channels you intend to use, apply power to the transmitter by
pressing the Power Button located on the front panel. The Display Screen should now be on.
Select the RF Channel on the transmitter to match the receiver channel. Turn the program
material on (tape recorder, PA, microphone etc.) Adjust the appropriate Audio Input Level
control until loud program material passages cause the Treble Clef Icon to just come on
with loud input or set the step to the next dB level down. This allows sufficient “headroom”
to prevent peak distortion on loud inputs. Set the High/Low power button to High position
initially. See operating Instructions for additional information.

Audio Monitor: After the audio input levels have been adjusted in the above procedure,
stereo headphones with a ¼ in. plug can be plugged into the Monitor jack. If you wish
to monitor the audio program material, turn up the monitor (volume) control to the
desired level. The monitor control does not affect the transmitted audio level.

System Walk Through: Now that the transmitter is set up, you should be able to hear the
program material on the appropriate receiver. Walk the receiver through the area that it is
intended to be used in. Check for any noise or interference that would cause undesired
operation. Some of the causes of poor performance are listed below.

Poor transmitter location.
Poor receiver location.
Interference.
Local AC Line noise.
RF “Trouble Spots.”
Operating distance beyond system capability.