Agilent Technologies 856290216 service manual SIG ID Oscillator Option

2.On the HP 85623, press (nCTRL) and EXTENNfi MIXER. The voltage on the DVM should measure approximately i-5 Vdc (TTL high).

3.On the HP 85623, press [SCTRL) and INTENNa MIXER. The voltage on the DVM should measure approximately 0 Vdc (TTL low).

4.Connect the positive lead of a DVM to A15J901 pin 13 (LSID). The signal measured turns on the SIG ID oscillator.

5.On the HP 85623, press SIG ID ON (if present), (SGL-).

6.Subsequent pushes of (j-1 should cause the signal measured on the DVM to toggle between TTL high and low levels.

7.Connect an oscilloscope probe to A15U902 pin 7 (LRDIR) and the probe ground lead to A15J901 pin 6. The signal measured controls the flatness compensation circuit.

8.On the HP 85623, press [e) and set the (SPAN) to 1 MHz.

9.Set the oscilloscope for the following settings:

Amplitude scale . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .2 V/div Sweep time . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . ..20ms/div

10.The waveform should be at a TTL high during part of the retrace period and a TTL low during the sweep (about 50 ms).

SIG ID Oscillator (Option 008)

Refer to function block F on Al5 RF Section Schematic Diagram (sheet 4 of 4) in the

HP 8560 E-Series Spectrum Analyzer Component Level Information.

SIG ID is available only with Option 008. The SIG ID Oscillator provides a shifted third LO (approximately 298 MHz) to distinguish true signals from false signals (such as image or multiple responses). When the HP 85623 is set to SIC ID t3N, the SIG ID Oscillator turns on during alternate sweeps.

1. Set the HP 85623 to the following settings:

Trigger . . . . . . . . . . . . . . . . . . . . . . . . , . . . . . . . . . . . . . . . . . . . . . . . . . . . . single sweep SIG ID . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . on

2.Use an active probe with another spectrum analyzer to measure the signal level at A15X602.

3.On the HP 85623, press (SGL$i?@1. With each press of (-1, the analyzer alternates between the following two states:

State 1:

A15J901 pin 13 (LSID)

SIG ID Oscillator

Signal at A15X602

State 2:

A15J901 pin 13 (LSID) SIG ID Oscillator

3rd LO Driver Amplifier

TTL low

ON

298 MHz f50 kHz (at least i-1 dBm)

TTL high

OFF

Provides LO for Double Balanced Mixer

RF Section 12-19