Option Installation
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Model 4010 Tone Remote System Adapter
One of the Tone Remote System Adapters (P/N 950-0255, or 950-9922) is required for the
Model 4010 to transmit to a tone controlled radio. The adapter has a 2175-Hz oscillator to
generate the required guard tone and has 2175-Hz filters to remove the low-level guard
tone from the received audio. Only one card is required per system, which allows all
channels the option of being a tone channel. The 950-0255 is a functionally equivalent
replacement of the 950-9717. The 950-9922 has additional audio delay features.
Installation
The cover of the Model 4010 must be raised by unscrewing the two thumbscrews on the
back of the unit and lifting the top.
The Tone Remote System Adapter is installed on the Control Board connector P4, which
is near the external AUX AUDIO connector. Remove any jumpers that may be on
connector P4. When installing the board, verify that the Tone Remote board pins are
aligned with the Main board connector and the right angle bracket on the adapter board
lines up with the mounting hole in the back panel. Secure the board by inserting the screw
through the back panel hole into the bracket.
Adjustments
The Tone Remote System Adapter comes from the factory adjusted for the nominal level
required by most transmitters. The guard tone level is set by the potentiometer that is
labeled GT. To maintain the proper signal level between the guard tone and audio signals,
the pot is set for a reading of 0.7 V
P-P
(-10 dB) at test point TP2, pin-6 (pin-1 is ground).
The guard tone is summed with the audio at the channel card. The transmit adjustment
(TX) for each channel controls the summed audio level. The difference between the high-
level guard tone and the low-level guard tone is fixed at 30 dB by the channel card. The
guard tone may also be monitored at the test points on the channel card, P1, but this level
is dependent on the TX potentiometer setting of each channel.
Caution!
Do not install this board with the power applied. Damage to
the board can occur. Keep the front of the unit on the tabletop;
do not let the front hang over the table edge. The console can
be knocked off balance onto the floor in this position.
!
Note
Test point TP2 and the notch filter jumpers are not available on
950-9717.