Radio Shack LCD RF Frequency Counter OWNER’S MANUAL

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OWNER’S MANUAL

Please read before using this equipment.

LCD RF Frequency Counter

Cat. No. 22-306

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FEATURES

Your RadioShack LCD RF Frequency Counter is a mi­crocomputer-based instrument that accurately mea­sures radio frequency (RF) or logic frequency signals.
It is ideal for the home electronic hob byist or a small re­pair shop. Use it to measure cordless telephone, ham,
CB radio, radio-controlled toy remotes, radio/TV cir­cuits, or digital instrument frequencies.

Your counter can measure RF signals within a 1 MHz–

1.3 GHz range or logic frequency signals within a
0 Hz–10 MHz range. You can display the frequency
with different resolutions and update rates.

The counter’s features include:

Selectable Measurement Gate Times

— let you
choose a fast setting for quick measurement updates
or a slow setting for maxim um resolution.

Selectable Input Impedance

— lets you select 50­ohm impedance (for use with the supplied antenna or
an optional 50-ohm coaxial cable) or high input imped­ance (for use with an opti onal high-impedance probe).

©

1997 Tandy Corporation.

RadioShack is a registered trademark used by Tandy Corporation.

All Rights Reserved.

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Selectable Input Frequency Range — you can
choose between 1 MHz and 50 MHz or between 50
MHz and 1.3 GHz for RF, or between 0 Hz and 10 MHz
for logic frequency.

BNC Connector — lets you connect the supplied an­tenna to measure through-air RF signals, or a cable
with a male BNC connector (not supplied) for direct fre­quency measurements.

Backlight — makes the display easy to see in low-light
conditions.

Hold — freezes the data on the display.

Recharging Circuit — lets you recharge nickel- cad-

mium batteries while they are installed in the counter.
You need four AA batteries or an AC adapter to use

this counter (see “Connecting Power” on Page 5).

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CONTENTS

Preparation ............................................................. 5

Connecting the Ant enna ..... .. ............................ 5

Connecting Power ............................................. 5

Using Batteries .......................................... 6

Recharging Nickel- C adm ium Batteries ...... 9

Using AC Power ....................................... 11

Connecting an Optional Coaxial Cable ........... 13

Operation .............................................................. 14

Turning On/Off the Counter ............................. 14

Setting the Input Impedance ........................... 14

Setting the Frequency Range ......................... 15

Setting the Gate Speed ................................... 16

Using the Backlight ......................................... 18

Using Hold ....................................................... 18

Measuring Frequencies ....... .. .......................... 19

Care and Maintenance ......................................... 23

Specifications ....................................................... 25

Ty pical Input Sensitivity .................. ................. 28

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PREPARATION

CONNECTING THE ANTENNA

To connect the supplied antenna to
the connector, place it over the con­nector on top of the counter and
align the r ecess on the antenna with
the two tabs on t he connector. Then
slightly push down on the antenna’s
connector and turn it clockwise until
it locks.

Note:

You can also connect an an­tenna (not supplied) that is tuned to
the frequency band of the signal
you want to measure.

CONNECTING POWER

You can power your counter from four AA batteries (al­kaline or rechargeable nickel-cadmium) or from a stan­dard AC outlet using an AC adapter ( not supplied).

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Using Batteries

Your counter can use four AA batteries (not supplied)
for power. We recommend alkaline batteries, such as
RadioShack Cat. No. 23-552. You can also use re­chargeable nickel-cadmium batteries, such as Cat. No.
23-125.

Cautions:

• Only use fresh batteries of the required size and
type.

• Do not mix old and new bat teries, different types of
batteries (standard, alkaline, or rechargeable), or
rechargeable batteries of different capacities.

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Follow these steps to install batteries into the counter.

1. Use a Phillips screwdriver to loosen the screw on
the counter’s battery compartment cover. Then
remove the co ver.

2. Using a small screwdriver , set the counter’s battery
type switch to the appropriate position —

LINE

for alkaline batteries or

Ni-Cd

for recharge-

ALKA-

able nickel-cadmium batteries.

3. Put the batteries in the compartment as indicated
by the polarity symbols (+ and –) marked inside.

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Warning: If you use alkaline or other non­rechargeable batteries, do not connect the AC
adapter to the counter with the battery type switch
set to

. Doing so activates the counter’s

Ni-Cd

charging circuit. Trying to charge non-recharge­able batteries can cause the batteries to leak or
explode, possibly causing personal injury.

4. Replace the battery compartment cover, then
tighten the screw to secure the cover.

When the battery voltage becomes too low, or there is
a low AC voltage condition,

appears on the low-

BATT

er left corner of the display and the counter might dis­play incorrect measurements. If

BATT

appears,
replace or recharge the batteries or check the AC con­nection.

To ensure consistent operation, replace alk ali ne batter­ies at least every 12 m onths.

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Recharging Nickel-Cadmium Batteries

To recharge nickel -cadmium batteri es, you need an AC
adapter (such as Cat. No. 273-1455) (see “Using AC
Power” on Page 11).

Warning:

Do not try to recharge alkaline or other non-

rechargeable bat ter ies. They might rupture or explode.

Follow these steps to recharge nickel-cadmium batter­ies while they are inside the counter.

1. Be sure the bat ter y type switch is set to

2. Plug the AC adapter’s barrel plug into the

Ni-Cd

.

DC 9V

jack on the left side of the counter.

3. Plug the other end of the adapter into a standard
AC outlet.

4. Charge the bat teries for 12 to 14 hours.

Caution:

Charging batteries for longer than the

recommended time can damage them.

5. Unplug the adapter from the AC outlet first. Then
unplug it from the

DC 9V

jack.

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Note: Occasionally, fully discharge nickel-cadmium
batteries before you recharge them. Otherwise, the
batteries lose their ability to fully charge.

Important: Your counter can use rechargeable nickel­cadmium batteries. At the end of a battery’s useful life,
it must be recycled or disposed of properly. Contact
your local, county, or state hazardous waste manage­ment authorities for information on recycling or disposal
programs in your area. Some options that might be
available are: municipal curbside collection, drop-off
boxes at retailers such as your loc al Radi oShack store,
recycling collection centers, and mail-back programs.

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