GW Instek GFC-8010H Скачать руководство пользователя страница 7

  FREQUENCY COUNTER

USER MANUAL

11

5-3. Maximum input voltage

The maximum input voltage Vs frequency characteristics is shown as    

Fig. 6.

Fig. 6. Maximum Input Voltage-Frequency

5-4. Typical Applications

Several examples for typical applications are described below:

1).The output frequency of a transmitter or transceiver can be measured

(if the output power is about 1W) by merely connecting a one turn clip

cord to several tens of centimeters from antenna. The length of the

distance is determined by the magnitude of the output.

  FREQUENCY COUNTER

USER MANUAL

12

2).Measurement can also be easily performed when calibrating the

oscillation frequency of a grid dip meter by merely connecting the one

turn clip cord.

3).Measurement of tracking the frequency through the oscillator stage,

multiplier stage, and output stage can be performed by making a small

2-3 turn coil and coupling it to each turned circuit (the oscillations may

be produced by the input capacitance and its resonant frequency with

too many turns of coil.)

Note: As the product has a high sensitivity, induction may cause

erroneous counting if you touch the red end (ungrounded side) of

the clip cord. Therefore, hold the black clip or coaxial cable when

performing measurements according to above method.

Measurement by connecting the accessory cable directly to the test

circuit is described below.

4).Measurement can generally be performed by merely connecting the

black side of the clip cord to ground (GND) and the red side to the test

point.

5).When the capacitance of the cable will have an affection on the test

circuit (When measuring turned circuits or high output impedance

circuit), perform measurement by inserting a high resistance in series

with the red side of the clip cord. Always be sure to ground the cord

when perform the measurement of 4) and 5) above. If possible, ground

the cable to the ground point of the test circuit. This procedure will

reduce the affection of noise. A wide variety of measurement can be

conceived in addition to (1~5) fully utilizing the special features of the

counter.

Содержание GFC-8010H

Страница 1: ...t 3 2 Checking the Line Voltage 3 3 Equipment Installation and Operation 3 4 General Preparation 3 3 3 4 4 4 PANEL INTRODUCTION 5 5 APPLICATION 5 1 Sensitivity 5 2 Input Sensitivity Characteristic 5 3 Maximum Input Voltage 5 4 Typical Applications 7 7 10 11 11 6 CIRCUIT DESCRIPTION 6 1 Theory of Operation 6 2 Frequency Measurement Accuracy 13 13 14 7 MAINTENANCE 7 1 Standard Method for Calibration...

Страница 2: ...igh quality crystal allows an extremely accurate measurement of frequencies FREQUENCY COUNTER USER MANUAL 2 2 TECHNICAL SPECIFICATIONS Sensitivity rms 10Hz 10MHz 15mV 10MHz 40MHz 20mV 40MHz 80MHz 35mV 80MHz 120MHz 50mV Input Impedance 1MΩ 35PF Max Input Voltage 150Vrms Coupling System AC coupling Time Base Oscillation Frequency 10MHz Aging rate 1 10 6 Month Temp stability 25 5 5 10 6 0 50 2 10 5 A...

Страница 3: ...eration Ensure there is proper ventilation for the vents in the case If this equipment is used not according to the specification the protection provided by the equipment may be impaired 3 4 General Preparation 1 When the impedance is 1MΩ the maximum voltage applied to the input depends on the frequency and the position of the SENSITIVITY switch This relationship is shown in Fig 6 and the values g...

Страница 4: ...ate time button to 10 sec 1 sec or 0 1 sec for measurement 6 Power ON OFF Power on or off by using the button 7 Gate Time LED The gate time of 10 sec 1 sec or 0 1 sec will be displayed in the LED by setting the Gate button 8 Over LED Overflow indicator shows that one or more of the most significant digits are not displayed 9 Displayed LED Display 8 digits of frequency data 10 Exponent and units LE...

Страница 5: ...he difference between these two voltage VH V V is called the hysteresis voltage But if both V and V don t react each other no output will be obtained and the Schmitt circuit will not work out with the states of 1 2 and 3 of Fig 3 shown as below Fig 3 States under which the schmitt circuit doesn t work From above description it can be easily understood whether or not the Schmitt circuit works is at...

Страница 6: ...s larger than VH perform measurements by first setting SENSITIVITY to 1 10 then set it to 1 1 range to protect the input circuit and avoid erroneous counting One good method is to conduct measurements at the smallest possible input within the counter display value dispersion range When the signal is a pure waveform it will not occur erroneous counting with any magnitude input lower than the input ...

Страница 7: ...duced by the input capacitance and its resonant frequency with too many turns of coil Note As the product has a high sensitivity induction may cause erroneous counting if you touch the red end ungrounded side of the clip cord Therefore hold the black clip or coaxial cable when performing measurements according to above method Measurement by connecting the accessory cable directly to the test circu...

Страница 8: ...en reflected through the gain of the proceeding three amplifier states including the Q201 Q202 pair results in about a 5mV hysteresis in the input triggering levels to aid in noise rejection Q203 and Q204 translate the ECL levels to TTL levels The signal is presented directly to the counter IC U301 The IC U301 provides all the functions of the counter and display result through LED U201 regulates ...

Страница 9: ...mbient temperature is because the crystal oscillator is similar to it If the temperature of the crystal oscillator is assumed to be 25 and set to 10MHz that is over the worst case temperature stability of 2 10 5 0 60 temperature range and since the frequency is 10MHz a variation of only 10 106 2 10 5 2 102 200Hz is possible In actual use worst case conditions are produced in two circumstances 1 Fr...

Страница 10: ...ek under the constant ambient temperature state as a percentage of 0 0001 FREQUENCY COUNTER USER MANUAL 18 7 MAINTENENCE The following instructions are executed by qualified personnel only To avoid electrical shock do not perform any servicing other than the operating instructions unless you are qualified to do so 7 1 Standard method for calibration After 50 minutes warm up apply the STD OUT signa...

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