Lectrosonics UM500 User Manual
Page 12
UM500
The best RF protection is accomplished by installing RF bypass capacitors at the mic capsule. If this is not possible,
or if you are still having problems, capacitors can be installed on the mic pins inside the TA5F connector housing.
2 WIRE MIC
3 WIRE MIC
CAPSULE
SHIELD
AUDIO
SHIELD
AUDIO
BIAS
TA5F
Preferred locations for bypass capacitors
CAPSULE
CONNECTOR
TA5F
CONNECTOR
Alternate locations for bypass capacitors
Install the capacitors as follows: Use 330 pF capacitors. Capacitors are available from Lectrosonics. Please specify
the part number for the desired lead style.
Leaded capacitors: P/N 15117
Leadless capacitors: P/N SCC330P
All Lectrosonics lavaliere mics are already bypassed and do not need any additional capacitors installed for proper
operation.
Caution
When wiring the connector, do not use the connector body for any electrical connections. A common mistake is to use the
connector body as an audio ground. The connector body is already used as an RF ground on VHF models and no other use
is permitted.
LINE LEVEL SIGNALS
The normal hookup for line level signals is: Signal Hot to pin 5, Signal Gnd to pin 1, pin 4 jumped to pin 1, and pin 3
jumped to pin 1. This gives a 40dB attenuator that allows signal levels much higher than 3V to be applied without
limiting.
If more headroom is needed, insert a 100k resistor in series with pin 5. Put this resistor inside the TA5F connector to
minimize noise pickup.
If lower than normal line levels (less than 1V) are expected, use this hookup: Signal Hot to pin 5, Signal Gnd to pin
1, and pin 4 jumpered to pin 1. This provides a 20dB attenuator allowing signals as high as 3V to be applied without
limiting.
WIRING HOOKUPS FOR DIFFERENT SOURCES
SHIELD
AUDIO
BIAS
3 WIRE ELECTRET MIC
POSITIVE BIAS
PIN
1
2
3
1
2
3
4
5
SHIELD
AUDIO
2 WIRE ELECTRET MIC
NEGATIVE BIAS
4
TA5F
5
PLUG
SHIELD
AUDIO
2 WIRE ELECTRET MIC
POSITIVE BIAS
SLEEVE
1
PIN
SHIELD
2
AUDIO
3
TIP
4
1
2
3
4
5
LINE LEVEL
TA5F
RCA or 1/4 " PLUG
5
PLUG
(See notes on ‘LINE LEVEL SIGNALS” above.)
PIN
1
2
3
4
1
2
3
4
5
TA5F
5
PLUG
PIN
1
2
3
4
1
2
3
4
5
TA5F
5
PLUG
SHIELD
BIAS
AUDIO
3 WIRE ELECTRET MIC
NEGATIVE BIAS
3
1
2
PIN
PIN
PIN
1
1
1
2
SHIELD
2
2
3
3
3
4
4
1
2
3
4
5
DYNAMIC
Dynamic LO Z mic or electret with
1
2
3
4
5
TA5F
TA5F
manufacturers power supply.
MIC LEVEL
5
5
PLUG
PLUG
LECTROSONICS, INC.
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