There are two E/F-band Lewis scanners. These are believed to be the azimuth and elevation air search elements, although this radar would not normally function in isolation, and would usually receive target prompts from any one of a variety of volumetric search radars.
An F-band element is possibly used for target tracking whilst G-band elements are for missile guidance.
An I-band element reportedly has a range only (RO) function for accurate range measurement whilst a D-band element may have an IFF application.
ZD-2(B) is the designator given to the complete missile guidance station associated with the HQ-2B missile, whilst 2FA(B) is the radar transmitter/receiver sub-assembly.
The RF and PRF/PRI value suffixes (refer book) imply their linkage during transmission. G2 may represent a second transmission source with subtly different parameters, to reduce the probability of mutual interference if they operated in close proximity.
The Lewis Scan search technique combines the output of two separate assemblies that are set at 90° to each other.
The RF feeds rotate independently to achieve horizontal and vertical scans respectively, over a narrow sector at a medium data rate, usually between 10 and 25 Hertz and one source has suggested a rate between 15.5 and 17 Hz This system is ageing and is not included in the CRIA 2004 list of indigenously supplied equipment (refer book).
However, whilst it might still be materially supported, it is probably out of production and due for replacement.
In the meantime its major attributes appear to have been retained in the visually less sophisticated SJ-202 (see separate entry), which is being promoted for export.
This radar has been exported to Albania, Iran, North Korea and Pakistan.