Lectrosonics ALP690 Active Log Periodic Antenna

Built for wireless mic receivers in location or studio production, the Lectrosonics ALP690 is an active, directional log periodic antenna with a built-in RF amplifier.

It gives +4 dBd of passive gain toward the front, with less sensitivity above, below, and behind, to extend operating range. Its amplifier takes its power from DC bias on the coax, supplied by a Venue Series receiver, an active multicoupler, or an inline bias-T. The amplifier then adds -6 to +12 dB of gain in 1 dB steps to offset loss in long cable runs.

Active and Passive Use

With no power on the cable, it switches to passive operation on its own, and in passive mode it also works as a transmitter antenna. In active mode, filtering covers 470 to 608 MHz or 470 to 700 MHz for different regions. A keypad and LED readout set the gain, the filter, and the display brightness.

Build and Mounting

Copper traces on a 0.133 in glass epoxy laminate form the elements, and the skeletal shape reduces wind loading outdoors. Mounted vertically, it covers a wide horizontal pattern. The supplied mounting block has threaded sockets for 1/4-20 and 3/8-16 tripods and 5/8-27 mic stands, and it rotates 90 degrees. The optional ALPKIT adds stainless steel adapters.

Features

• Selectable RF filtering, 470 to 608 MHz or 470 to 700 MHz
• Directional pattern with 4 dBd of gain
• Built-in RF amplifier with adjustable gain for cable loss
• Keypad and membrane switches with LED readout
• Switches to passive mode when no DC power is present
• Weather-tolerant build for indoor and outdoor use
• Skeletal structure reduces wind loading
• Supplied mounting block, with an optional adapter kit