ALT1000 Assistive Listening Transmitter
The flexible ALT1000 transmits quality audio in both stereo and monaural modes - a feature that sets Drake’s assistive listening transmitter apart from the competition. This high quality, commercial grade transmitter performs superbly in applications where music/message fidelity is a must. The ALT1000 also provides easy operation via front panel push button controls and LCD indication of frequency.
Architectural and Engineering Specifications
The Transmitter shall operate in the 72-76 MHz Auditory Assistance Band as approved by the FCC. Specifically, the transmitter shall operate on the wideband channels spaced at 100 kHz increments on frequencies of 72.1 to 72.9, 74.7, and 75.5 to 75.9 MHz. The transmitted field strength shall not exceed 80 millivolts per meter at a 3 meter distance. The operating frequency and mode: Stereo or Mono shall be shown on an LCD display and be programmable by front panel tune UP/DOWN buttons. The transmitter shall be FCC and Industry Canada approved.
Maximum FM deviation shall not exceed ±75 kHz. Frequency stability shall be controlled by a phase-locked loop frequency synthesizer with crystal reference and shall be accurate within ±0.001% from 0-50° C. The transmitter shall permit fitting of a 7" flexible whip antenna mounted through the top cover of the unit, or permit connection of an optional magnet mount antenna, with coaxial cable, to a rear panel connector. Only the particular antenna type intended for this connection shall be specified.
The transmitter shall have XLR connectors for balanced audio inputs and RCA Phono connectors for unbalanced audio inputs. The transmitter shall provide a GROUND LIFT switch for the XLR inputs. The transmitter shall provide full deviation for monaural input signals to the LEFT AUDIO INPUT connectors when programmed for the MONO mode. The transmitter shall permit switch selection of no limiting, limiting only, or limiting and compression operation from a rear panel switch. There shall be a front panel control to adjust the audio input level with an LED OVERMODULATION indicator. There shall be a front panel 1/4" stereo monitor jack with volume control.
The transmitter shall be powered by an external AC line to 12 VDC power adapter. The rear panel shall have a power switch and front panel display indication when power is active. The transmitter shall be rack mountable in a standard 1 RU rack steel package. The R.L. Drake ALT1000 Assistive Listening Transmitter is specified.
Features and Benefits
- FM Assistive Listening Component
Can Be Used Indoors or Outdoors, in Bright Light and Without Line of Site restrictions. - Operates Within 72-76 MHz
FCC Designated Frequency Range for Assistive Listening. - Coverage of 700,000 Square Feet
Insures That Message is Heard By Everyone in the Audience. - Powerful RF Output
Eliminates Need for Additional Costly Equipment in Larger Venues. Maximum Output Allowed by the FCC. - Direct Audio Input
Easily Integrated Into Existing Audio System. - Stereo and Monaural Operation
Provides Versatility To Audio system and Enhanced Audio Reception. - Built-in Selectable Audio Limiter and Compressor
Provides Automatic Limiting to Prevent Loud Bursts and Overmodulation. - Front Panel LCD Readout and push button tuning
Insures Easy Programming and Verification of Desired Frequency. - Rack Mountable Size
Optional Magnetic Mount Antenna Available for Rack mounted Installations. Supplied Antenna For Stand Alone.
| ALT1000 Transmitter Technical Specifications | |
|---|---|
| Selectable Frequencies: | 72.1 to 72.9, 74.7, and 75.5 to 75.9 MHz |
| Frequency Selection: | Selectable by front panel up/down keys and LCD frequency read-out. |
| Frequency Generation: | PLL Synthesis |
| Frequency Stability: | ±10 ppm, 0° to 50° C |
| Tuning Step Size: | 100 kHz |
| Modulation: | FM, 230KF3E, multiplex stereo or mono |
| FM Deviation: | ±75 kHz, maximum |
| Pre-Emphasis: | 75 µSec. |
| RF Field Strength: | 80 mV/m @ 3 m with supplied antenna or optional magnetic mount antenna |
| Input Limiting: | Switch selectable, low distortion |
| Audio Compressor: | Switch selectable, 2:1 compression range limited |
| Audio Inputs: | 2 XLR (left & right audio), 2 RCA Phono (left & right audio) |
| Frequency Response: | 20 Hz to 15 kHz, ±3 dB referenced to a standard 75 mSec pre-emphasis curve |
| Ultimate S/N Ratio With Drake Model MR306 Receiver: | >60 dB, monaural, >55 dB, stereo |
| Total Harmonic Disortion: | Less than .25%, typical |
| Power Requirement: | 12 VDC @ 250 mA, by supplied wall adapter |
| Antenna: | Flexible 7 inch whip (optional magnetic mount antenna) |
| Size & Weight: | 19" W x 1.75" H x 6.25" D (with antenna removed) 5 lbs. |
Specifications, price, and availability are subject to change without notice or obligation.
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