17.Tune the source 1 kHz above the fractional N frequency. The voltage measured on the DVM should be approximately -12 Vdc.

18.If the DVM reading does not change, the Al4 frequency control assembly is defective. Reconnect W32 to A14J501. Replace the jumper on A14J23 to the NORM position.

SYNTHESIZED

SWEEPER

DIGITAL VOLTMETER

TEST CABLE

A14J2/3

A14i501

P I N 3

 

A14J23

PIN 1

Sp127e

Figure 11-3. YTO Loop Test Setup

Check Al5 RF assembly (steps 19-25)

19.Disconnect W34 from A15UlOOJl and disconnect W32 from A15JlOl.

20.Connect a frequency counter to A15JlOl. Connect a high-frequency test cable from an HP 8340A/B synthesized sweeper to A15UlOOJl. See Figure 11-4.

21.Connect a BNC cable from the spectrum analyzer 10 MHz REF IN/OUT to the HP 8340A/B FREQUENCY STANDARD EXT input.

22.Set the HP 8340A/B to the following settings:

Frequency standard . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . EXT Powerlevel . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . -5dBm

23. Set the spectrum analyzer to the following settings:

Span . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . OHz Trigger . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Single

24.Set the spectrum analyzer and HP 8340A/B frequencies to the combinations listed in Table 11-5 and press (SGLSWP) on the spectrum analyzer.

Synthesizer Section 11-l 1

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Agilent Technologies 856290216 service manual YTO Loop Test Setup Check Al5 RF assembly steps, Synthesizer -l