Watkins-Johnson Company WJ-8718A/MFP Instruction Supplement page 112

WJ-8718A/MFP
SECTION IV
MAINTENANCE
TABLE 4-1
4.1 GENERAL
The maintenance information which follows supplements Section IV (Maintenance)
in the WJ-8718 Series HF Receiver Instruction Manual. In that manual, when reference is made
to a standard circuit board which has been replaced by an MFP Option board, the referenced
circuit should be changed to the equivalent MFP board, as listed in Table 4-1.
Table 4-1. MFP Equivalent Circuits
Standard MFP Equivalent
Ref. Ref.
Type Desig. Board Type Desig.
Board
- -
- -
791828 A6A2 Front Panel Interconnect 794308-2
MFP-A3 IF Interface
791575 A6A1
Manual/Up/Down Counter 794275-X MFP-A4 Synthesizer Inter-
face
791684 A10 Front Panel Control 794310 MFP-A1 Front Panel Switch/
Encode Assembly
791578 A8 Frequency Display 794310
MFP-A1
Front Panel Switch/
Encode Assembly
791874 A7 Manual Tuning Module 794310 MFP-A1 Front Panel Swit-ch/
Encode Assembly
791827 A9 BFO Switch 794310 MFP-A1 Front Panel Switch/
Encode Assembly
34836 A7U1 Encoder Assembly 791202-5 MFP-A2 Encoder Assembly
4.1.1
PERFORMANCE TESTS
Performance tests should be utilized to confirm operating specifications during
initial inspection, during periodic checks, during troubleshooting, and after repairs. A receiver
equipped with the MFP Option can be tested in the manual mode, following the proc·edures
outlined in the WJ-8718 Series HF Receiver Instruction Manual, which establishes the required
receiver parameters for using the MFP operating procedures in paragraph 2.4.4 . of this
supplement. The MFP Option is programmed with a diagnostic Built-In Test Equipment (BITE)
program which verifies the operation of the front panel switches and LEDs, as well as the
operation of microprocessor circuits involved in the execution of the program. The BITE
program is discussed in paragraph
4.1.1.1. .
The MFP Option is also programmed with diagnostic Receiver BITE Tests which aid
in the troubleshooting of the receiver's IF and Synthesizer Sections, ±l'5power supplies, and the
random access memory (RAM) associated with the microprocessor. The Receiver BITE T..ests
are discussed in paragraph 4.1.1.2.
4-1