Microwave Converter

Model 11793A

4.Insert the paper under one of the contacts, and while pressing gently on the contact, slide the paper through. Do not allow the alcohol to run inside the switch assembly. Do not allow the paper to shred. Do this several times and repeat for the other switch contact.

5.Saturate the edge of another sheet of paper with a freon-type degreaser and repeat step 4.

6.Remove any shreds of paper that may have lodged in the contacts.

7.Reinstall the switch cover. Note the orientation of the feedthrough terminals on the cover with respect to the switch contacts.

8.Replace the switch according to Paragraphs 4 1 or 42, RF Module assembly procedures.

37.Instrument Disassembly Procedure

The 11793A Microwave Converter uses metric connecting hardware in the form of 3 mm (T10) and 4

mm(TlS) Torxhead screws (except for two small English thread Pozidriv screws mounting U1 to MP17). Use the Torxhead size T 10 and T 15 bits that are provided, to disassemble and re-assemble the instrument. The recommended torque wrench for use with the Torxhead bits may be ordered as HP part number 8730-0012.

The major component blocks of the 11793A Microwave Converter are MP14 (RF Signal Processing Module), A1 (A1 Switch Control Assembly), and T1 (Power Transformer). The RF module and the A1 assembly are mounted on MP13 (the Main Deck). The power transformer is mounted on MP2, the instrument chassis left side strut. See Figures 6, 7, and 8 to locate and identify parts and assemblies.

Note that Option 020 and 021 instruments differ from the standard and other option models in that the main deck and transformer locations inside the instrument are reversed when compared to the standard and other option models as shown in Figures 7 and 8. In Option 020 and 021 models, the RF module is in the rear of the instrument), and the transformer is mounted in the front left corner.

The following procedures allow the removal of the Microwave Converter components from within the instrument chassis.

1.Remove the top and bottom covers by loosening the screw in the middle of each cover rear edge. These are captive screws and will cause the cover to push away from the front frame. Slide each cover toward rear of the instrument to disengage, then lift up and away from the instrument.

2.Remove the side covers in the same manner as that of the top and bottom covers.

3.Remove the plastic trim from the top of the front frame by inserting a screwdriver into the rear slots and gently prying up the strip.

4.Disconnect J 8 on the rear panel by removing the 9/16 inch retaining nut and lock washer.

5.Instruments with serial number prefix 2S20A have MP8 (back panel) riveted to MP3 (rear

frame). To remove the rear frame, unscrew the four corner screws that connect MP2 (side struts) to MP3. Pull off the two wires 05 and 0 (black/green and black) on the LINE VOLTAGE switch (both wires are of the quick disconnect type).

For instruments with serial number prefix 2407A, remove MP8 (back panel) from MP3 (rear frame) by unscrewing eight screws. Pull off the two wires OS and 0 (black/green and black) on the LINE VOLTAGE switch (both wires are of the quick disconnect type).

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