Wideband Hand Held Transmitter
Rio Rancho, NM
5
Pilot Tone Squelch
The benefit of the pilot tone squelch system is that the
associated receiver will remain muted until it receives
the pilot tone from the matching transmitter, even if a
strong RF signal is present on the carrier frequency
of the system. All Digital Hybrid Wireless
®
transmitters
use one of 256 different ultrasonic tones between 25
and 32 kHz in each standard frequency b to operate
the receiver squelch.
The HHa is a wideband design that tunes across three
standard bands (up to 76 MHz). The pilot tone frequen-
cy is determined by the selected operating frequency
in 100 kHz steps. In other words, the same pilot tone is
used for all four frequencies within each 100 kHz step
of the tuning range. This preserves compatibility with
earlier Digital Hybrid products that tune across a single
frequency band (25.6 MHz).
Input Gain Range and Limiter
45 dB range of input gain adjustment allows gain
settings to accurately match the user’s voice and the
varying sensitivity of different microphone capsules. A
DSP-controlled analog audio limiter is employed be-
fore the A-D converter. The limiter has a range of more
than 30 dB for excellent overload protection. A dual re-
lease envelope makes the limiter acoustically transpar-
ent while maintaining low distortion. It can be thought
of as two limiters in series, a fast attack and release
limiter followed by a slow attack and release limiter.
The limiter recovers quickly from brief transients, with
no audible side effects, and also recovers slowly from
sustained high levels to keep audio distortion low while
preserving short term dynamics.
Long Battery Life
Switching power supplies throughout the design al-
low over 5 hours of operation using two alkaline AA
batteries. The battery compartment and contacts are
designed to prevent “rattle” as the unit is handled.
Menu-Driven Control
A high-resolution LCD and control panel with mem-
brane switches provide access to the menu-driven
setup. Transmitter RF power, high-pass filter, frequency
selection, backlight timeout, mute or talkback functions
and tuning modes are easily accessed.
Wideband Tuning Range
The transmitter can tune across band of up to 76 MHz
in either 100 kHz or 25 kHz steps.
Frequency Selection
Operating frequency is normally selected using a
receiver or analyzer to assess signals in the local en-
vironment to avoid interference. Once an interference-
free frequency is identified, the transmitter frequency is
set to match the receiver.
The LCD on the transmitter displays frequency in MHz
and with a two character hex code that is used on
most Lectrosonics receivers.
Antenna
A newly designed helical antenna allows the transmit-
ter to be held in any position, since the user’s hands
have little or no effect on the RF output power.
Microphone Capsules
The transmitter is available from Lectrosonics with
the HHC and HHVMC cardioid condenser capsules.
Capsules from several other manufacturers are also
available for use with the HH: those with a 1.25” x 28
thread pitch and three contact rings. Condenser or
dynamic microphone heads can be used with the HH,
depending on the user’s preference or the application.
IR (infrared) Sync
An IR Sync Port is used for quick setup with receivers
that offer this feature. Settings for frequency, step size
and compatibility mode are transferred from receiver to
transmitter via the IR ports.
Side Button Functions
A programmable switch on the side of the housing can
be configured as a mute/cough switch, to provide a
talkback function, a power switch, or be disabled.
The talkback function provides a communication
channel when used with a receiver equipped with this
feature, such as a Venue Wideband receiver with ap-
propriate firmware. When pressed and held in, the side
switch re-directs the audio output to a different audio
channel on the receiver. As soon as the switch is re-
leased, audio is returned to the program channel.
The talkback function works only in the Digital Hybrid
compatibility mode.
USB Port for Firmware Updates
Firmware updates are enabled by simply downloading
a file and utility program from the Lectrosonics web
site, connecting the transmitter to a computer via the
USB port and running the program.
