Static & Lighting Chokes

General Purpose Lighting Choke for AM Towers Model TC-300

Lighting chokes are used to pass tower lighting voltages across the base insulator of a series-fed tower without appreciably altering the tower impedance. LBA TC-300 general purpose tower lighting chokes are provided for three wire 110/220 VAC circuits. Maximum current is 25 amps. These chokes are rated for peak base voltages to 10,000 volts, and present a typical reactance of +j5000 ohms at 530 kHz. Bypass capacitors are provided on each winding.

TC-300 lighting chokes should be protected from the weather. LBA Technology offers the TCC-1 weatherproof cabinet with feed through insulator to accommodate outdoor mounting of these chokes.

High Voltage Strobe Lighting Choke for AM Towers Model BALC-20

Providing an AC feed to strobe lighting systems on high power AM towers can be problematic. The ring-type chokes often used for tower light feeds on high voltage towers often do not function well under the low pulse loads of stroboscopic lighting systems. Traditional lighting chokes, such as the LBA TC-300 do not have a sufficiently high RF voltage rating.

The LBA Model BALC-20 high voltage lighting choke is specifically made to withstand 30 KV medium wave peak RF voltages. It is particularly suited for broadcast systems of 100KW and above. It provides a three wire 110/230 volt AC feed at a nominal maximum 1000 V/A. Equivalent shunt impedance is above 10,000 ohms.

The Model BALC-20 is intended for interior placement in the antenna tuning unit and coupling to the tower feed line as an AC conduit. It has multiple high voltage corona grading rings and robust mica RF bypass capacitors. Mounting is on a furnished floor base with overall height of 46”H x 14”D x 14”W. A special custom outdoor cabinet can be furnished if required.

Static Dissipation Chokes Models SD-1 & SD-2

Static drain chokes are employed to drain static charges from towers before they build up to levels that could damage equipment or harm personnel. Ungrounded towers should always be connected to a static drain choke, unless a tower lighting choke with ground is employed. They are designed for installation inside antenna tuning units and other equipment.

LBA offers the SD-1 for RF base voltages to 10 KV peak. The SD-2 is recommended for RF base voltages to 20 KV peak. Custom static chokes are available for higher voltage systems.

Available RF & Lighting Chokes

Where system design requires, LBA can furnish a complete line of leading toroidal ring transformers for all RF voltage and lighting current levels.   LBA has produced a number of specialty systems over the years including a custom dual TC-300 lighting choke in a large TCC-1 cabinet.  This special unit is for AC & DC isolation for an AM-Celluar colocation system.