1097A Filter Description and Use

Product Overview

The 1097A filter is a specialized narrowband filter designed specifically for use with the 147C amplifier. Its primary function is to facilitate accurate toning and pair identification in environments where electrical noise or power line interference is present. By filtering out unwanted electrical noise, the device ensures that the test tone remains clear and audible.

Technical Requirements

The 1097A filter is precisely tuned to a frequency of 577.5 Hz. For optimal performance, it must be used in conjunction with a precision tone source, such as the KS-14103 L6 breakdown test set or the 138A test set. Using an ordinary tone source will result in unsatisfactory and intermittent operation. The filter is housed in a compact, molded plastic case and features a permanently attached cord and plug assembly.

Installation and Power

The 1097A filter does not contain its own batteries. Instead, it is powered directly by the 147C amplifier through the REC jack. To install, simply snap the filter onto the side of the 147C amplifier and insert the plug into the REC jack. Please note that the 1097A filter is only compatible with the 147C amplifier; it will not function with the 147B amplifier as it does not provide the necessary battery voltage. To conserve battery life, always unplug the filter from the amplifier when the equipment is not in use.

Operation and Adjustment

Proper adjustment of the amplifier-filter combination is essential for best performance. The recommended procedure involves adjusting the gain of the 147C amplifier while listening to the noise level before the filter is inserted. Once the gain is set, the 1097A filter is connected, and the tone source is adjusted to a usable level. In electrically noisy environments, the tone level should be set higher, while in quiet areas, a lower setting is sufficient. Once these adjustments are complete, the system is ready for fault location and pair identification operations.