1. General Information

WARNING: Before turning on the in­strument, ensure that it has been installed in accordance with the In­stallation Instructions outlined in Chapter 1 of the User’s Manual.

This performance procedure is intended for:

  • checking the instrument’s specification.
  • incoming inspection to determine the ac­ceptability of newly purchased instruments and recently recalibrated instruments.
  • checking the necessity of recalibration af­ter the specified recalibration intervals.

NOTE: The procedure does not check every facet of the instrument’s calibration; rather, it is concerned primarily with those parts of the instrument which are essential for determining the function of the instrument.

It is not necessary to remove the instrument cover to perform this procedure.

2. Preparations

Power up your instrument at least 30 minutes before checking to let it reach normal operating temperature. Failure to do so may result in certain test steps not meeting equipment specifications.

3. Test Equipment

Type of EquipmentRequired Specifications
Reference Oscillator  10 MHz, 1×10-8 (e.g. 6688) for calibrating the standard TCXO oscillator
10 MHz, 1×10-9 (e.g. 6689) for calibrating Opt 30 & Opt 40 (OCXO)
Voltage CalibratorDC -50 V to +50 V (e.g. Fluke 5500) for calibrating the built-in voltage ref­erence, alternatively corresponding DC power supply + DVM with uncertainty <0.1 %
LF SynthesizerSquare/ Sine up to 10 MHz, 10 VRMS
Pulse Generator2 ns rise time, 5 V peak, >10 MHz, continuous & one-shot trigger
Oscilloscope1 GHz, <3% voltage uncertainty
RF Signal Generator0.1 to 3, 10, 15, 20, or 24 GHz dep. on RF input, <1dBm level uncertainty, 10 MHz ext.ref.
Power Splitter50 Ohm 6dB BNC
Termination50 Ohm feed through BNC
Low-pass Filter50 kHz (for 1 MOhm) load
BNC CablesApprox. 10 pcs of suitable lengths
Table 5. Recommended equipment for calibration and performance check.

4. Internal Self-Tests

Internal self-tests are run on every instrument power up. In case of a failure information message box appears described the type of the error.

5. Front Panel Controls

5.1. Touch Panel and Keyboard Test

  • Press Settings icon on top right. Open User Options Recall Defaults. Confirmation dialog will appear.
  • Press Yes.
  • Press BACK hard button. Main Settings screen will appear.
  • Press Advanced, then press Signal Source and select Test.
  • Press ABOUT in bottom right corner. About box will appear.
  • Press OK.
  • Press HOME hard button. Measurement screen will appear. Frequency around 1 MHz will be measured.
  • Press HOLD hard button. Measurement will be put in HOLD after current one finishes.
  • Press RESTART hard button. Instrument will perform single measurement.
  • Press Measurement Function name in top left corner. Function selection dialog will appear.
  • Select Period Period Single A, B.
  • Press OK. Measurement screen will appear.
  • Press AUTOSET hard button. Autoset progress dialog will appear followed by “Autoset finished” notification.

6. Short Form Specification Test

6.1. Sensitivity and Frequency Range for Inputs A, B, D, E

  • Recall Defaults
  • Select Frequency A.
  • Select 50 Ω input impedance, 1x attenuation, Manual Trigger Levels and Absolute Trigger Level A 0V.
  • Select Preamp ON
  • Connect a signal from a HF generator to a BNC power splitter.
  • Connect the power splitter to Input A of your counter and an oscilloscope. Set the input impedance to 50 Ω on the oscilloscope.
  • Adjust the amplitude according to the following table. Read the level on the oscilloscope. The timer/counter should display the correct frequency.
  • Repeat the measurements and input settings above for Input B, D, and E.
Frequency   MHzLevel  Pass/Fail  
Table 6. Sensitivity for inputs A, B, D & E at various frequencies

6.2. Sensitivity and Frequency Range for RF Input (Input C)

To verify the specifications of the different RF prescalers, use the following basic test setup:

  • Connect the output of a signal generator covering the specified frequency range to the RF input (C) of the Analyzer.
  • Connect the 10 MHz REF OUT from the generator to the EXT REFon the rear panel of the Analyzer. Choose External in Settings → Advanced → Timebase Reference.
  • Select Frequency C as Measurement Function.
  • Generate a sine wave in accordance with the data in the relevant table (Table 7, Table 8).
  • Verify that the Analyzer is counting correctly. (The last digits will be unstable).
Frequency GHzAmplitude dBm
Table 7. RF input sensitivity, Option 10 (3 GHz)
Frequency GHzAmplitude dBm
Table 8. RF input sensitivity, Option 110 (10, 15, 20 or 24 GHz)

6.3. Voltage

  • Recall Defaults.
  • Select Vpp A
  • Select DC coupling and Filter 10 kHz. Do not apply an input signal to Input A yet.
  • The display should now indicate (disregard the main parameter Vpp): Vmin= 0 ± 0.015 V and Vmax= 0 ± 0.015 V
  • Adjust the current limit of the DC voltage source to <200 mA.
  • Connect +2.500 Vdc to Input A, using the external 50 kHz low-pass filter on the input.
  • The display should now indicate: Vmin = 2.500 ± 0.040 V and Vmax = 2.500 ± 0.040 V Repeat the measurement with inverted polarity.
  • Select Input A and select 10x.

CAUTION: Before the next step, make sure the input impedance is still 1 MΩ. Applying more than 12 V without proper current limiting may cause extensive damage to the main PCB, if the impedance is set to 50 Ω.

  • Change the DC level to +50.00 V.
  • The display should now indicate: Vmin = 50.00 ± 0.65 V and Vmax = 50.00 ± 0.65 V Repeat the measurement with inverted polarity.
  • Disconnect the DC voltage from Input A. Remove the external low-pass filter.
  • Select Input A and select 1x.
  • Connect the LF generator to Input A, and set an amplitude of 4.000 Vpp and a frequency of 100 kHz. Verify the Amplitude with a good Voltmeter
  • The display should now indicate: 4.000 ± 0.150 Vpp.
  • Select Input A and select 10x.
  • Change the amplitude to 18.00 Vpp.
  • The display should now indicate: 18.00 ± 1 Vpp. Disconnect the LF generator from Input A.
  • Select Input A and select 1x, 50 ohm, and Filter = OFF.
  • Connect the RF generator to Input A and set an amplitude of 4.000 Vpp and a frequency of 100 MHz. Verify the amplitude on an oscilloscope.
  • The display should now indicate: 4.000 ± 0.40 Vpp. Select Input A and select 10x.
  • Change the amplitude to 18.00 Vpp.
  • The display should now indicate: 18.00 ± 2.2 Vpp
  • Proceed by repeating the measurements for Input B, D, and E, as described above for Input A.

6.4. Reference Oscillators

X-tal oscillators are affected by a number of external conditions like ambient temperature and supply voltage. Aging is also an important factor. Therefore, it is hard to give limits for the allowed frequency deviation. The user himself must decide the limits depending on his application and recalibrate the oscillator accordingly.

To check the accuracy of the oscillator you must have a calibrated reference signal that is at least five times more stable than the oscillator that you are testing. See Table 7-6 and the list of test equipment on page 7-2. If you use a non-10 MHz reference, you can use the mathematics in the timer/counter to multiply the reading.

  • Recall Defaults.
  • Connect the reference to input A
  • Check the readout against the accuracy requirements of your application.

6.4.1. Acceptance Test

Table 7 can serve as an acceptance test and gives a worst case figure after 30 minutes warm-up time. All deviations that can occur in a year are added together.

OscillatorFrequency ReadoutSuitable ReferenceP/F
Standard (TCXO)10.00000000 MHz + 150 Hz6688 
Option 30 (OCXO)10.00000000 MHz + 1Hz6689 
Option 40 (OCXO)10.00000000 MHz + 0.25 Hz6689 
Table 9. Acceptance test for oscillators

6.5. Resolution Test

  • Connect the pulse generator to a power splitter.
  • Connect one side of the power splitter to Input A on the Analyzer using a coaxial cable.
  • Connect the other side of the power splitter to Input B on the Analyzer.

Settings for the pulse generator:

  • Amplitude = 4 Vpp, (high level +4 V and low level 0 V) Period = approx. 1 ms
  • Duration = approx. 50 ns
  • Rise time = 2 ns

Settings for the Analyzer:

  • Recall Defaults,
  • Select Time Interval Single A, B,
  • Set for Inputs A & B: 50 Ω, DC coupling, Manual Trigger Levels,
  • Set Absolute Trigger Level A to +1 V,
  • Set Absolute Trigger Level B to +1 V,

The standard deviation (std) should be less than 140 ps, corresponding to a resolution of 7 ps per timestamp.

7. Rear Inputs/Outputs

7.1. 10 MHz OUT

  • Connect an oscilloscope to the 10 MHz output on the rear of the Analyzer. Use a coaxial cable and 50 Ω termination.
  • The output voltage should be sinusoidal and >1Vp-p, typically 1Vrms.


  • Recall Defaults.
  • Connect a stable 10 MHz signal (e.g REF OUT from another counter/analyzer) to input A. Connect a 10 MHz, 100 mVRMS, (0.28 Vp-p) signal from the LF synthesizer to EXT REF. Select Ext Ref. from the Timebase Oscillator setting menu
  • The display should show 10 MHz.
  • Change the external reference frequency to 5 and 1 MHz.
  • The counting should continue, and the display should still show 10 MHz.


  • Proceed from the test above.
  • Settings for the pulse generator:
    • single shot pulse,
    • manual trigger,
    • amplitude TTL = 0 – 2 VPP, and
    • duration = 10 ns.
  • Connect the pulse generator to Ext Arm Input.
  • Set Start Arming to EA on the Analyzer. The Analyzer does not measure.
  • Apply one single pulse to Ext Arm Input.
  • The Analyzer measures once and shows 10 MHz on the display.


  • Connect an oscilloscope to the pulse output on the rear panel with a 50 Ω coaxial cable terminated at the scope input with 50 Ω (internally or externally).
  • Enter Settings → Pulse Output.
  • Set Mode to Pulse Generator. Select Pulse Period and set the value to 1000 ns. Select Pulse Width and set the value to 500 ns.
  • The output signal should be a pure square wave signal with 1 MHz frequency and 50 % duty cycle. The rise/fall time should be approximately 2.5 ns. The low and the high level should be <0.2 V resp. >2.4 V.

8. Measuring Functions

  • Recall Defaults
  • Set Settings → Advanced → Signal Source to Test
  • Set Sample Interval to 200 ms
  • Set DC, 50 Ω, Manual Trigger Levels, Absolute Trigger Level to 0.5 V for Inputs A, B, D, E
  • Go through Measurement Functions from the Table 8 and verify the results.

Note that the results in the table are rounded off and very approximate. Test signal is not synchronized to Analyzer timebase and can generate Frequencies far from nominal. No tolerances are given for this test.

Measurement FunctionDisplayPass/Fail
Frequency A,B,D,E1 MHz 
Smart Frequency A,B,D,E1 MHz 
Frequency Ratio A,B,D,E1 
Period Average A,B,D,E1 us 
Smart Period Avg A,B,D,E1 us 
Period Single A,B (D, E)1 us 
Time Interval A,B,D,E>-100 ps, <100ps 
Time Interval Single A,B,D,E>-100 ps, <100ps 
Acc. Time Interval A,B,D,E>-100 ps, <100ps 
Phase A,B (D,E)0° (360°) 
Acc. Phase A,B (D,E)0° (360°) 
TIE0 s 
Pos. Duty Cycle A (B,D,E)0.5 
Neg. Duty Cycle A (B,D,E)0.5 
Pos. Pulse Width A,B (D,E)500 ns 
Neg. Pulse Width A,B (D,E)500 ns 
Rise Time A, B (D,E)< 5 ns 
Fall Time A, B (D,E)< 5 ns 
Rise-Fall Time A (B,D,E)< 5 ns 
Pos. Slew Rate A, B (D,E)>350 MV/s 
Neg. Slew Rate A, B (D,E)<-350 MV/s 
Totalize A,B,D,Eincrements 
Totalize X+Y A,B,D,Eincrements 
Totalize X-Y A,B,D,E0 
Totalize X/Y A,B,D,E1 
Vmin A,B,D,E0 V 
Vmax A,B,D,E2 V 
Vp-p A,B,D,E2 V 
Vminmax A (B,D,E)Vmin=0 V, Vmax=2 V 
Table 10. Measurement Functions check

8.1. Optional RF Input C

  • With an optional RF input (Input C) you will require an external RF source to verify Input C. A simple functional check can be performed by connecting a 1 GHz, -10 dBm signal after selecting Freq C. No other settings need to be changed.
  • Read 1 GHz on the display

9. Check of HOLD OFF Function

  • Recall Defaults
  • Select Period Single A
  • Set DC, 50 Ω for Input A
  • Connect the rear panel output marked 10 MHz Out to Input A. The Analyzer will display 100 ns
  • Increase Hold-Off Time setting (Settings → Measurement → Hold-Off Time) in steps from 0 s to 120 ns
  • While Hold-Off Time is below 100 ns the result will be about 100 ns (one period). As soon as Hold-Off Time exceeds 100 ns (e.g. 110 ns), the result displayed will be about 200 ns (two periods)