Remote Control Console
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6.4.1.1 MICROPHONE AUDIO
RV7 adjusts the level of microphone audio that is summed with the other four transmit audio sources. This
potentiometer should be adjusted only when microphone audio must be changed relative to the hold tone
output. In otherwords, use this potentiometer only to bring microphone levels to a predetermined level
above the hold tone. Use RV4 (See 4.1.3) to increase audio levels to the remote site. At the factory, this
potentiometer is set so that a 700mV input to the TLM card from the Switch Bus Module produces a signal
that is 20db higher than the 2175hz hold tone at TP7.
6.4.1.2 CROSSPATCH TRANSMIT AUDIO
RV8 adjusts the level of microphone audio that is summed with the other four transmit audio sources. This
potentiometer should be adjusted only when the crosspatch transmit audio must be changed relative to the
hold tone output. In otherwords, use this potentiometer only to bring crosspatch transmit levels to a
predetermined level above the hold tone. Use RV4 (See 4.1.3) to increase audio levels to the remote site. At
the factory, this potentiometer is set so that a 700mV input to the TLM card from the Switch Bus Module
produces a signal that is 20db higher than the 2175hz hold tone at TP7.
6.4.1.3 TRANSMIT DRIVER
RV4 controls the output level of the TLM. This level is accessible from the back and, in most cases, is the
only potentiometer in the transmit path that need be adjusted to obtain proper system levels.
6.4.1.4 TONE OUTPUT
This potentiometer is for fine adjusting the tone output level. Be very cautious when engaging in this
adjustment as that all transmit levels are shipped relative to the tone output.
6.4.1.5 NOTCH ADJUSTMENTS
The notch filter is designed for a center frequency of 2175Hz. TLM cards are shipped from the factory set at
a 2175Hz notch. The notch adjustments are then “potted” with a compound so the potentiometer will not
change value. The notch circuit should be adjusted only if a different notch frequency is desired.
Adjustments are designed into the circuitry in the first place so that the factory can compensate for
component tolerances.
To adjust the notch filter, insert the desired notch tone to the aux. audio input on the plug-in terminal blocks
at the rear of the UIM (the unit that holds the touchscreen). The input level should be as high as possible
without measuring clipping at TP3 on the TLM. Adjust RV10 for the greatest amplitude at U16.8. Next
adjust RV11 for the smallest amplitude at TP6. Make fine adjustments to both RV10 and RV11 for the lowest
possib le amplitude signal at TP6.
6.4.1.6 DTMF OUTPUT LEVEL
Potentiometer RV15 controls the output level of the DTMF on the TLM. At the highest level DTMF will
transmit around 0.975V at the summing point tested by TP7.
6.4.2 RECEIVE SIDE ADJUSTMENTS
The receive circuitry processes the receive audio and distributes it to the proper circuitry for analysis. The
audio coming in the receive side is fed to a Line Activity Monitor (LAM), DTMF decoder, Parallel transmit
detect, recorder, and the Select/Unselect/Xpatch RX busses. The following chart lists the potentiometers in
the receive path.
Reference
Access
Description
RV1
external
Line input gain adjustment
RV2
external
TX monitor level (for 4 wire mode)
RV5
internal
ALC knee of compression adjust
RV9
external
LAM active level
RV3
internal
Bus output level
RV14
external
Recorder output level
RV12
internal
Notch frequency phase control
RV13
internal
Notch frequency adjust
