MFJ MFJ-888 User Manual

MFJ-888

Frequency Counter

Instruction Manual

I n t r o d u c t i o n

The MFJ-888 frequency counter is a compact, pocket sized test instrument, designed for ease of use and dependable performance. This manual is intended to help these who have never used a frequency counter get started as quickly as possible. For these

users familiar with test and measurement equipment, complete specifications and a detailed description of operation controls is included.

Features

∙50 ohm input for range I MHz to 3 GHz coverage.

1Meg ohm input for range 10 Hz to 50 MHz.

∙High Speed 300 MHz direct count with 0.1 Hz per second resolution.

∙10 digit LCD display.

∙Ultra sensitive synchronous detector 16 section bar graph of RF signal strength.

∙Hi-Z low range:

∙Measures frequency and period.

∙LED Backlight

∙Beeper.

∙Low power consumption 6-hour NiCd battery operation.

∙Low battery indicator.

∙Automatic held.

∙Held switch locks display.

∙4 selectable gate speeds.

∙Supplied with telescoping whip antenna and AC wall adapter.

SPECIFICATIONS

Input Sensitivity (Typical)
Amplifier			I Meg Ohm				50 ohm
Impedance			I Meg Ohm, 30 pF				50 ohm, VSWR<2:1
Range			10 Hz - 50 MHz				1 MHz - 3 GHz
_			<10 mV a 10 Hz - 10 MHz				<0.8 mV @u 100 MHz
Sensitivity			<20 mV @ 10 MHz50 MH				<7 mV @..3D0 MHz.
							<6 mV u. I GHz
							<I00mV@2.4GIIz
Maximum Input			100 Vans				15 dBm
Frequency Display			Resolution				I.,
Range		Gate Time		LCD	Sample Display
300 MHz		0.0625 Sec		10 Hz	300.00000		MHz
		0.25 See		I z	300.000000		MHz
		I Sec		I Hz	300.000000		MHz
		4 Sec		0.1 Hz	300.000000		MHz
3 GHz		0.0625 Sec		1000 Hz	3000.000 MHz
		0.25 Sec		100 Hz	3000.0000 MHz
		I Sec		10 Hz	3000.00000 MHz
		4 Sec		10 1 1z	3000.00000 MHz

RF Signal Strength Bargraph

	Frequency		Ist Segment		Full Scale
		27 MHz	7 mV		100 mV
		150 MHz	5 mV		90 mV
		800 MHz	10 mV		200 mV
Cabinet:		Stamped aluminum with black anodized finish.
Display:		10 digit Liquid Crystal Display.
Size:		3.15" H X 2.7" W X 1.22" D
Weight:		250g
Battery:		Internal 4 AA 600 mAH NiCd battery pack.
Power:		9 VDC, 300 mA wall plug adapter.
Time-base: <I PPM typical at room temp.
C O N T R O L S

POWER SWITCH

This slide switch turns on power to the counter and initiates a 2.0 second test of all LCD segments.

AMP SWITCH

This slide switch selects either the I Meg ohm high impedance amplifier or 50 ohm amplifier.

RANGE SWITCH

This slide switch selects the frequency range to count. Select 300 MHz for frequencies between 1 MHz and 300 MHz. Select 3 GHz for frequencies between 10 MHz and 3

GHz. When the range switch is in the 3 GHz position, the prescaler will be activated and "Prescale" will appear on the LCD.

LITE SWITCH , .

This slide switch turns the LCD back light on and off.

FUNCTION BUTTON

This button selects the measurement mode of frequency or period. This button has four settings. The four modes of operation are Frequency Display, Period Display, Frequency Display with automatic HOLD, and Period Display with automatic hold.

HOLD BUTTON

This button will stop the counter from counting and keep the current display unchanged.

GATE BUTTON

This button selects the gate or measuring time. A longer gate means counting for a longer period and results in more digits displayed. The four gate speeds are 0.0625 sec, 0.25 sec, I sec, and 4 sec.