Lectrosonics UM400a Digital Hybrid UHF Belt Pack Transmitter - Used

Lectrosonics UM400a Digital Hybrid UHF Belt Pack Transmitter - Used
Lectrosonics UM400a Digital Hybrid UHF Belt Pack Transmitter - UsedLectrosonics UM400a Digital Hybrid UHF Belt Pack Transmitter - UsedLectrosonics UM400a Digital Hybrid UHF Belt Pack Transmitter - Used
Lectrosonics UM400a Digital Hybrid UHF Belt Pack Transmitter - UsedLectrosonics UM400a Digital Hybrid UHF Belt Pack Transmitter - Used

Lectrosonics UM400a Digital Hybrid UHF Belt Pack Transmitter - Used

  • Used.  8 / 10 Condition.
  • Marks around the unit.
  • Small scratches on side of unit (see photos)
  • Block 24 (614.400 - 639.900)

The latest digital/analog hybrid technique is presented in a classic Lectrosonics wireless belt-pack transmitter. 24-bit digital audio is combined with optimized FM to create unprecedented audio quality and RF performance. The RF transmission is an aggressively optimized FM system with +/-75kHz wide deviation for a high signal to noise ratio. The overall system delivers full bandwidth audio frequency response up to 20kHz and the operating range of the finest analog wireless systems.

The innovative servo bias input on the standard 5-pin connector provides a programmable, regulated voltage to accommodate a wide variety of electret microphones. It is no longer necessary to install resistive pads for some mics to prevent overload of the input stage, divide the bias voltage down for some low voltage mics, or reduce the limiter range at minimum gain settings. To simplify wiring connectors, a single configuration for all microphones is now available for the UM400a transmitter input, and an alternate wiring configuration works well with all 5-pin inputs on Lectrosonics transmitters.

Compatibility with earlier analog Lectrosonics receivers and even some receiver models from other manufacturers is provided by custom firmware emulations built into the DSP code. A simple procedure using the frequency and power switches selects the desired operating mode


  • Digital Hybrid Wireless Technology
  • 256 synthesized UHF frequencies
  • 100 mW output power
  • DSP controlled dual envelope input limiter
  • SDP emulations for analog compatibility
  • Servo bias input preamp
  • DSP based pilot-tone signal
  • Circulator / Isolator output stage
  • Adjustable low frequency roll-off

Digital Hybrid Wireless™ , a revolutionary design that combines digital audio with an analog FM radio link to provide outstanding audio quality and the extended operating range of the finest analog wireless systems. The process eliminates a compandor and its artifacts. The design overcomes channel noise in a dramatically new way, digitally encoding the audio in the transmitter and decoding it in the receiver, yet still sending the encoded information via an analog FM wireless link. This proprietary algorithm is not a digital implementation of an analog compandor. Instead, it is a technique which can be accomplished only in the digital domain, even though the audio inputs and outputs are analog signals. 

The UM400a is powered by a single 9V battery and provides a full 100mW output for extended operating range. The housing and belt-clip are machined aluminum, powder coated and laser engraved for ruggedness and legibility.

Two 16-position rotary switches adjust the operating frequency of the transmitter over a 25.6 MHz bandwidth in 100 kHz steps.

The low frequency roll-off is adjustable from 35 Hz to 150 Hz to control the presence of extremely low frequency audio in the program material.


Frequency Selection 256 frequencies in 100 kHz steps
RF Power output 100 mW (nomial)
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
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)
Weight 6.98 ozs. - 198 grams (including battery & antenna)
Dimensions 3.17 x 2.48 x .84 inches

Delivery Services

At Pinknoise Systems we like to offer our customers a wide choice of delivery options for their orders, and our prices are affordable and competitive. We also use only the best, most reliable couriers and delivery services to get your equipment where it needs to be - quickly and securely. Please find an outline of our services, prices and timescales below.

Service Timescale Price
UK Mainland Royal Mail Small Parcel 2-4 Days £3.99
UK Offshore Royal Mail 2-4 Days £9.99
UK Standard Courier 2-4 Days £6.49
UK Express Courier Next Day £7.99
International Shipping From 1-8 Days (Full Details) From £15.00

Delivery Times

Delivery times are based on when the packages leaves our premises. Sometimes, due to stock restrictions or a non completed order, delivery may take longer as there is a delay with dispatch. We will always notify customers of any issues and problems via email or telephone. If your order is urgent or details change please do let us know.

For full details, fees, and time schedules, please see our Delivery Information page.

Returns & Refunds

New items: You can return goods you have ordered from us for any reason, at any time within 7 working days of receipt, for a full refund or for an exchange for a different product from our range. The cost of returning goods to us shall be borne by you, the customer, in all circumstances without exception.

Items must be packed suitably and insured for full loss in the event of a delivery problem. Pinknoise Systems will not be responsible for lost or damaged return goods. Lost or damaged goods may effect the level of refund you receive.

Used items: Please note this does not apply to used item unless they are deemed faulty.

For full details of our returns policy, please click here.

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£499.00 (£415.83 Exc. VAT)


1 in stock, no more available  

1 in stock, no more available

Delivery hours
UK ORDERS: Order soon for delivery on using our express service

Part No.:  PPN-13
Manufacturer:  Lectrosonics

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(+44) 01453
825 802

International Delivery

International delivery

We ship across Europe and around the world and have a multitude of shipping options available to our international customers during the checkout, including express delivery for urgent orders.


We have a next day shipping option available for the UK with our DPD courier service, which features delivery alerts, personal delivery preferences and driver tracking with the DPD mobile app.


Spread the cost to maximise your capital. Just call our helpful sales team on 01453 825 802, from 9.30am - 5.30pm, to discuss these options and find out what's available to you.

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Lectrosonics UM400a Digital Hybrid UHF Belt Pack Transmitter - Used

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