HP 8560A Low Band Problems (50 Hz to 2.9 GHz)

Table 11-2. TAM Tests versus Test Connectors

Connector	Manual		Probe Troubleshooting					Tes	leasured Signal Lines
A14J17	Main Coil Course DAC								MS3
A14J18	LODA		Drive						IIS5, MS6, MS7, MS8
A14J19	Second		Conv		PIN	Switch			MS8
	Second		Conv		Mixer		Bias		MS1
	Second		Conv		Drain		Bias		MS3
	Second		Conv		Doubler Bias				MS4 .
	Second		Conv		Driver		Bias		MS5
	First	Mixer		Drive		Switch			MS7
	First	Mixer		Drive		DAC			MS6
A14J302	Revision								MS7
A15J400	IF AMP/Limiter Bias								MS6
A15J502	Third LO Tune Voltage								MS3
	3rd LO Driver Amp								MSl, MS8
A15J602	SIG	ID	Collector			Bias			MS7
	RF	Gain Control				Test			MSl, MS3
A15J901	Revision								MS3
	External		Mixer Switch						MSl, MS8
	Signal ID Switch								MS5, MS6
	External		Mixer Bias						MS7
	RF Gain Test								MS2

Low Band Problems (50 Hz to 2.9 GHz)

1.Disconnect all inputs from the front-panel INPUT 500 connector.

2.Set the HP 8560A to the following settings:

C E N T E R F R E Q . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 0 Hz SPAN . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .1 MHz I N P U T ATTEN . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . OdB

3.The LO feedthrough’s amplitude observed on the display should be between -6 and

- 3 0 dBm.

Note	The marker will not PEAK SEARCH on the LO Feedthrough when in a
	non-zero span. To measure the LO Feedthrough amplitude with the markers,
	set the SPAN to 0 Hz and CENTER FREQ to 0 Hz. Press (MKR) ON.

4.If the LO feedthrough’s amplitude is within limits, but signals are low, the RF path following the A8 Low Band Mixer is operating properly.

5.If the LO feedthrough’s amplitude is higher than -5 dBm (signal will be “clipped” at top of screen) and signals are low in amplitude, suspect a defective A8 Low Band Mixer.

11-4 RF Section