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Cat. No. 19-1126
OWNER’S MANUAL
HTX-242 TWO-METER MOBILE TRANS-
CEIVER
Please read before using this transceiver.
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INTRODUCTION Your HTX-242 Two-Meter Mobile Transceiver is an exciting addi- tion to Radio Shack’s growing line of high-quality amateur radio equipment. It offers some of the most advanced, and most requested, features available in a mobile transceiver. Be sure to read this entire manual to understand how to use all the radio’s features. You must have a Technician Class or higher Amateur Radio Operator’s License and a call sign issued by the FCC to legally transmit using this transceiver. T
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Programmable Frequency Step—lets you set the frequency step for tuning or scanning to 5, 10, 12.5, 20, 25, 50, or 100 kHz. Extended Band Coverage —receives from 136 to 174 MHz and lets you extend transmit coverage to include 2-Meter ham, MARS (Military Amateur Radio Service), and CAP (Civil Air Patrol). Dual VFO (Variable-Frequency Oscillator) and Duplex Modes— two independent VFOs let you quickly select between two directly- entered frequencies. You can also use one of the VFOs as a repeate
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CONTENTS Installation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6 Unpacking the Transceiver . . . . . . . . . . . . . . . . . . . . . . . . . 6 Connecting the Microphone . . . . . . . . . . . . . . . . . . . . . . . . . 6 Mounting the HTX-242 in a Vehicle . . . . . . . . . . . . . . . . . . . 7 Connecting an Antenna . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8 Connecting to your Vehicle’s Power . . . . . . . . . . . . . . . . . . . 9 Using the HTX-24
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Advanced Operation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 25 Frequency Offset Defaults . . . . . . . . . . . . . . . . . . . . . . . . . 25 Turning Auto Duplex On and Off . . . . . . . . . . . . . . . . 25 Changing the Default Offset . . . . . . . . . . . . . . . . . . . . 26 Reversing the Offset . . . . . . . . . . . . . . . . . . . . . . . . . . 26 Overriding the Duplex Offset . . . . . . . . . . . . . . . . . . . . 26 Using the Dual VFOs for Duplex Operation . . . . . .
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INSTALLATION Unpacking the Transceiver As you unpack the transceiver, check to be sure you have all the items shown in this illustration. Connecting the Microphone Plug the microphone’s connector into the microphone jack, secure the microphone holder to either the left or right side of the trans- ceiver, then clip the microphone to the holder. 6
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Mounting the HTX-242 in a Vehicle When you select a mounting location for the HTX-242, be sure: • You can easily reach it • No wires or cables will interfere with the vehicle’s operation • It is not directly in front of heating vents • All wires will reach their connection points Cautions: • To avoid damaging your vehicle’s electronic systems, contact your vehicle’s manufacturer before you install the HTX-242 to find out about the proper transceiver mounting locations, antenna loca- tions, and
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Connecting an Antenna You can connect a variety of antennas for both mobile and base- station use (see “Using the HTX-242 as a Base Station” on Page 10). Each type of antenna has its benefits. Choose one that best meets your needs. When deciding on a mobile or base-station antenna and its loca- tion, consider the following: • The antenna should be as high as possible on your vehicle or house. • The antenna and antenna cable should be as far away as possible from sources of electrical noise (
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Connecting to your Vehicle’s Power Follow these steps to power the HTX-242 in your vehicle. 1. Connect the black wire to your vehicle battery’s negative (–) terminal or to a metal part of the vehicle’s frame. Be sure the metal part is not insulated from the vehicle’s frame by a plastic part. 2. Connect the red wire to a source of voltage that turns on and off with the ignition and that can handle the transceiver’s 10-amp maximum power draw. Or, if you do not want the HTX-242 to turn on and
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Using the HTX-242 as a Base Station Although we designed the HTX-242 primarily for use as a mobile transceiver, you can also use it as a base station. To do so, you need these items: • 13.8-Volt DC regulated power supply that can supply at least 10 amps continuous power • Base station antenna • 50-ohm coaxial antenna cable and connectors Follow these steps to connect the HTX-242 as a base station. 1. Mount the base station antenna according to its instruc- tions. Warning: For your safety, fol
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Using the HTX-242 with Packet Radio You can connect your HTX-242 directly to a packet radio terminal node controller, as shown below. Note: You can purchase an 8-pin plug that matches your HTX- 242’s MIC jack at your local Radio Shack store (Cat. No. 279-440). Connecting an External Speaker (Optional) You can connect an external speaker to your HTX-242. Use an 8-ohm communications or PA speaker that can handle 5 or more watts of power (such as Radio Shack Cat. No. 21-549). The 1 speaker’s cab
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UNDERSTANDING THE HTX-242 This section explains some of the HTX-242’s features. See “Basic Operation” on Page 16 for instructions about how to use these fea- tures. Dual VFO Modes The VFO (Variable-Frequency Oscillator) modes let you directly select a frequency anywhere within the HTX-242’s operating range. Your HTX-242 has two VFOs: VFO-A and VFO-B. You typically use the VFOs to tune to frequencies you have not stored into one of the HTX-242’s memory channels (see “Memory Channels” on Page
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Subaudible Tone (CTCSS) Features Subaudible tones, also known as CTCSS (Continuous Tone-Coded Squelch System) are low-frequency tones that are mixed with a transmission. They are used by many repeaters to limit interfer- ence from other nearby radio transmitters. When a repeater uses a subaudible tone, it does not react to any transmission that does not include that tone. Your HTX-242 includes all 38 standard subaudible tones. You can set your HTX-242 to include any of these tones with your
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Understanding the Display One or more of the following indicators appear when you turn on and use your HTX-242. VFO-A or VFO-B — appears when you select one of the VFO modes. See “Dual VFO Modes” on Page 12. VFO-A-T VFO-B — appears when you select the DUP-A mode (transmit on VFO-A and receive on VFO-B). See “Using the Dual VFOs for Duplex Operation” on Page 27. VFO-A VFO-B-T — appears when you select the DUP-B mode (receive on VFO-A and transmit on VFO-B). See “Using the Dual VFOs for Dupl
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+ or – — indicates the duplex offset direction. See “Overriding the Duplex Offset” on Page 26. DTMF — appears when you turn on DTMF squelch. See “Using DTMF Page” on Page 33. HIGH or LOW — indicates the transmit power level. See “Setting the Power Level” on Page 17. ON-AIR — appears when you transmit. See “Transmitting” on Page 22. — appears when you turn on the Channel 1 alarm. Flashes when there is a transmission on Memory Channel 1 and the alarm is turned on. See “Checking Priority Chan
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BASIC OPERATION Turning On/Off Your HTX-242 To turn your HTX-242 on or off, press POWER. When you turn it on, all display elements briefly turn on and the HTX-242 sounds five tones. Then it returns to the last-used settings. Resetting the HTX-242 When you first use your HTX-242, if it displays PLL Err or EEP Err, or if you ever want to reset the HTX-242 to the factory defaults and clear all memory, follow these steps. Important: This procedure clears all stored information. ! 1. Turn off the
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Setting Volume and Squelch SQUELCH sets the minimum signal level that must be present for the HTX-242 to amplify the signal through the speaker or to stop when scanning. Follow these steps to set the squelch. 1. Rotate SQUELCH fully counterclockwise. 2. Set VOLUME so you can hear the background hiss between transmissions. Note: If you do not hear hissing, turn TUNE/M-CH to select a frequency that does not have communications in progress. 3. Slowly turn SQUELCH clockwise until the hissing sto
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Selecting a Frequency You can select a frequency in any of three ways: • Direct entry • Tuning • Scanning Directly Entering a Frequency 1. Press VFO to select either VFO-A or VFO-B. 2. Enter the last five digits of the frequency. For example, to enter 145.050, simply press 45050. Notes: • The HTX-242 rounds the last digit down to 5 or 0. • The HTX-242 does not accept entries outside its range. ! • If you have turned on the AS option, the HTX-242 automatically selects the correct duplex offset
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Scanning for a Frequency 1. Press VFO to select either VFO-A or VFO-B. 2. Press F. Then press s to scan up or t to scan down. Notes: • You can set the HTX-242 to scan in 5, 10, 12.5, 20, 25, 50, or 100 kHz steps. The default is 20 kHz. See “Setting the Frequency Step” on Page 19. • You can program up to five frequencies for the HTX-242 to skip when scanning. See “Storing Scan Skip Frequencies” on Page 20. • When the HTX-242 reaches one end of the scanning range, it starts over at the other e
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Setting the Scan Options Storing Scan Skip Frequencies You can store up to five frequencies for your HTX-242 to skip when scanning. This lets you prevent the HTX-242 from stopping on beacon or packet repeater frequencies. 1. Press VFO. 2. Hold F for at least 1 second. FUNC flashes. 3. Press MR. The HTX-242 displays SC and the current scan resume setting. 4. Repeatedly press s until the HTX-242 displays S1 and the first scan skip frequency (or –––.––– if no frequency is stored). 5. Select th
