UM400a
Lectrosonics
UM400a
Lectrosonics UM400a Lavalier Transmitter
This transmitter implements the latest Digital Hybrid Wireless® technology in a classic Lectrosonics belt-pack transmitter. A 5-pin input jack provides taps for low impedance dynamic mics, electret lavalier mics with positive or negative bias and line level inputs. Input gain is adjustable over a 43 dB range to perfectly match the audio input level for optimum modulation, minimum distortion and maximum signal to noise ratio. Input levels are accurately indicated by two LEDs on the control panel.
The servo bias input on the standard 5-pin connector provides a programmable, regulated voltage to accommodate a wide variety of electret microphones.
The servo bias input on the standard 5-pin connector provides a programmable, regulated voltage to accommodate a wide variety of electret microphones.
Product Weight: 7 oz including battery and antenna
Dimensions: 3.17"W x 2.48"H x .84"D
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Manufacturer Specs
Frequency selection: 256 frequencies in 100kHz steps
RF Power output: 100 mW (nominal)
Pilot tone: 25 to 32 kHz; 5kHz deviation
Frequency stability: ± 0.002%
Deviation: ± 75 kHz (max)
Spurious radiation: 90 dB below carrier
Equivalent input noise: –120 dBV (A-weighted)
Input level: Nominal 2 mV to 300 mV, before limiting. Greater than
1V maximum, with limiting.
Input impedance:
Dynamic mic: 300 Ohms
Electret lavaliere: Input is virtual ground with servo adjusted constant
current bias
Line level: 2.7 k Ohms
Input limiter: Dual envelope “soft” limiter; greater than 30 dB range
Gain control range: 43 dB; semi-log rotary control
Modulation indicators: Dual bicolor LEDs indicate modulation of -20, -10, 0 and +10 dB referenced to full modulation
Audio Performance (overall system)
Frequency Response: 32 Hz to 20 kHz (+/-1dB)
THD: 0.2% (typical)
SNR at receiver output:
Note: the dual envelope “soft” limiter provides exceptionally good handling of transients using
variable attack and release time constants. Gradual onset of limiting in the design begins below full
modulation, which reduces the measured figure for SNR without limiting by 4.5 dB.
Input Dynamic Range: 125 dB (with full Tx limiting) Low frequency roll-off
Adjustment: –18 dB/octave; adjustable from 35Hz to 150Hz
Controls:
• Two position “ON-OFF” power switch
• Audio input gain knob
• Low frequency roll-off pot on side panel
• Two 16-position rotary switches adjust frequency
Audio Input Jack: Switchcraft 5 pin locking (TA5F)
Antenna: Detachable, flexible wire supplied
50 Ohm port allows connection to test equipment
Battery: Precision compartment auto-adjusts to accept any known 9 Volt battery
Battery Life: 5 hours (alkaline); 10 hours (lithium)
Emission Designator: 180KF3E
RF Power output: 100 mW (nominal)
Pilot tone: 25 to 32 kHz; 5kHz deviation
Frequency stability: ± 0.002%
Deviation: ± 75 kHz (max)
Spurious radiation: 90 dB below carrier
Equivalent input noise: –120 dBV (A-weighted)
Input level: Nominal 2 mV to 300 mV, before limiting. Greater than
1V maximum, with limiting.
Input impedance:
Dynamic mic: 300 Ohms
Electret lavaliere: Input is virtual ground with servo adjusted constant
current bias
Line level: 2.7 k Ohms
Input limiter: Dual envelope “soft” limiter; greater than 30 dB range
Gain control range: 43 dB; semi-log rotary control
Modulation indicators: Dual bicolor LEDs indicate modulation of -20, -10, 0 and +10 dB referenced to full modulation
Audio Performance (overall system)
Frequency Response: 32 Hz to 20 kHz (+/-1dB)
THD: 0.2% (typical)
SNR at receiver output:
| SMARTNR | No Limiting | w/Limiting |
| OFF | 103.5 | 108.0 |
| NORMAL | 107.0 | 111.5 |
| FULL | 108.5 | 113.0 |
Note: the dual envelope “soft” limiter provides exceptionally good handling of transients using
variable attack and release time constants. Gradual onset of limiting in the design begins below full
modulation, which reduces the measured figure for SNR without limiting by 4.5 dB.
Input Dynamic Range: 125 dB (with full Tx limiting) Low frequency roll-off
Adjustment: –18 dB/octave; adjustable from 35Hz to 150Hz
Controls:
• Two position “ON-OFF” power switch
• Audio input gain knob
• Low frequency roll-off pot on side panel
• Two 16-position rotary switches adjust frequency
Audio Input Jack: Switchcraft 5 pin locking (TA5F)
Antenna: Detachable, flexible wire supplied
50 Ohm port allows connection to test equipment
Battery: Precision compartment auto-adjusts to accept any known 9 Volt battery
Battery Life: 5 hours (alkaline); 10 hours (lithium)
Emission Designator: 180KF3E