Pub. 42004-374A
Model 370-202 Interface Amplifier Assembly for Electro-Sound
Page: 5 of 9
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07/05
Checkout and Adjustment
1. After the Model 370-202 is installed and connected to the power, verify that normal use of the
Page/Party
®
system has not been affected by the addition of the Model 370-202 Interface Amplifier
Assembly. Make sure that the GAI-Tronics sidetone level (the amount of transmitted signal from the
microphone that is heard in the receiver) is not substantially affected when the interface is connected to
the system.
If oscillation, distortion, or excessive sidetone occurs, check the Model 370-202 installation wiring and
ensure that the Model 305-001 Line Balance Assembly is properly installed and connected. See
42004-139, the GAI-Tronics 700 Series Page/Party
®
Systems installation manual. If normal operation
is not restored, proceed to Step 3.
2. After the Model 370-202 Interface has been installed and connected to the Electro-Sound system and
the GAI-Tronics Page/Party
®
system, verify that a page initiated from the Electro-Sound system can be
heard over the page speakers on the Page/Party
®
system.
3. After system basic operation has been verified, adjust the Model 370-202 Interface if necessary. First,
establish communications between the Electro-Sound system and the Page/Party
®
handset station
nearest the interface. Follow Sub-steps A through C to complete the Model 370-202 adjustment.
Adjustments are made through the plugged access holes on the front cover.
A.
The
Balance Control
is adjusted for minimum sidetone at the GAI-Tronics station. To perform
this adjustment, blow into the microphone of the GAI-Tronics handset and adjust the balance
potentiometer on the Model 370-202 Interface to “null out” the microphone signal from the
receiver.
B.
Adjust the
Line to GAI-Tronics
potentiometer until the volume of the voice of the caller on the
Electro-Sound system is comparable to normal voice levels on the GAI-Tronics system. (See note
below).
C.
Adjust the
GAI-Tronics to Line
potentiometer until the volume of the signal from the GAI-Tronics
system to Electro-Sound system is comparable to normal system voice levels. (See note below).
N
OTE
:
If the
LINE
TO
GTC
and/or the
GTC
TO
LINE
controls are set too high, oscillation and
distortion may result. In this event, decrease these control settings, readjust the
BALANCE
control as necessary, and reset the
LINE
TO
GTC
and/or the
GTC
TO
LINE
controls for optimum
levels below the point at which oscillation occurs.
