The ML422 is a Selective Level Meter which is designed for use with Bell System FDM hierarchy. The ML422 covers the wide frequency range of 50Hz to 30MHz. This remarkable instrument offers highly accurate measurements of signal levels, and it has the frequency accuracy and stability needed to manufacture and maintain FDM systems, from voice frequencies up to 3600 channels. The ML422 can also function as a wideband level meter, psophometer, or voice band analyzer. Modification of input connector (ML422C only). Balanced input connectors are modified to I-214 type.
Options:
11 = ICC-2 Transformer Connector (GPIB to IEC-IB)
21 = Modifies the 124 and 135 ohm balanced input frequency ranges
31 = Modification of selective bandwidth
43 = Modification of FDM channel plan
