Headset Connections; Remote Mic Switch Connection; Unswitched, Unbalanced Mic Audio Output; Remote Footswitches For Talk On/Off - RTS RM-325 User Manual

{
Pin 2
Pin 3
Ch 2 Audio
To an Intercom Station
200 Ohms
LINE INPUT Connector
10µf/50V
Pin 1
3-Pin Male
XLR Connector
2
WIRES MUST NOT TOUCH!
Figure 5. Termination / power plug for 1 intercom
channel , with distributed power from a non-TW
power source

2.5 Headset Connections

Connect a stereo (default) or monaural headset to the
DYN MIC Headset connector. Or, connect a monaural,
carbon-mic headset to the CARB MIC headset connector.
Refer to the specifications (page 6) for pin-outs of these
connectors.

2.6 Remote Mic Switch Connection

If your headset is equipped with a mic on/off switch, you
can probably use it with the remote mic switch feature of
the RM-325. See "Mic On/Off Switch" in the operation
instructions, page 15.
If your headset does not have a mic switch, but you want
to use this feature, you can connect a remote mic switch
to the AUX connector. Or, you can change the setting of
the X3 jumper (page 8) and then use the CARB MIC
Headset jack for a remote mic switch. Refer to the
specifications (page 6) for pin-outs of these connectors.
2.7 Unswitched, Unbalanced Mic Audio
Output
The mic audio is available at the AUX connector for
connection to an external device, such as a PA amplifier.
The mic audio at this output is always on and will not be
switched off my the talk buttons. Refer to the
specifications (page 6) for unswitched mic pin numbers.
{
+18 to
+24 VDC
TO POWER
SUPPLY
+
Common
Resistor 200 Ohms, 1/8 Watt
Capacitor 10µ, 50V Electrolytic
Common
3
+18 to
+24 VDC
2.8 Remote Footswitches for Talk
On/Off
There are separate footswitch inputs for channel 1 and 2
at the AUX connector. A switch contact closure at either
of these inputs will have the same effect as turning on the
talk button for that channel. Refer to the AUX connector
specifications (page 6) for footswitch pin numbers.

2.9 Sidetone Adjustment

The sidetone trimmers control the level of the station
operator's own voice in the headphones while talking.
Normally, when using headphones that do not fully cover
the ears, no sidetone level is required, and the sidetone
trimmers should be adjusted to minimize the operator's
voice level. This also lessens the risk of feedback between
the headphones and microphone. When using headphones
that completely cover the ears, the sidetone level may be
increased to overcome the muffled sensation when
talking. Use a small flat-blade screwdriver through the
sidetone trimmer access holes in the front panel to
increase or decrease the voice level while talking on the
intercom channels. Note that there is a separate trimmer
for each channel.

2.10 Installation Notes

2.10.1Choosing Headsets or Handsets

The RM-325 accepts a wide variety of headsets and
handsets. Headset or handset choice depends on
operating environment, operating requirements, and
personal taste.
Table 3 shows typical operating environments and the
level of background noise present. The background noise
is measured using a Sound Pressure Level (SPL) meter,
which measures the sound pressure level in decibels. SPL
is useful for measuring environmental background noise,
comparing headphone efficiency, and predicting whether
speech communication is possible.
A very noisy/loud environment usually requires
headphones that prevent outside sound from leaking
in (again, good acoustic isolation), headphones that
can produce a loud, clear sound, and noise canceling
microphones.
Understanding speech in a noisy environment
requires that the sound from the headphones is as
loud or louder than the sound leaking into the
headphones from the noisy environment.
In general, the loudness of a headphone depends
upon its ability to absorb power at a given voltage
(power=voltage squared divided by the impedance)
and the efficiency of its design. Practically, the
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RM-325 User Manual