Cat. No. 19-1127 OWNER’S MANUAL Please read before using this equipment.
FEATURES Your RadioShack HTX-252 2–Meter FM Mobile Transceiver is a compact and versatile transceiver, perfect either in your vehicle or in your home. Vehicle cables and mounting hardware are supplied. Add an optional base-station antenna, cable, and a power supply to make it your home transceiver. It is an all-around ideal choice for your amateur communications needs.
Programmable Frequency Step — lets you set the frequency step for tuning or scanning to 5, 10, 12.5, 15, 20, 25 kHz. Signal Strength Indicator — a graduated bar shows the relative strength of the received signal and transmitting signal. Digital Phase-Locked Loop (PLL) Frequency Synthesizer — provides highly accurate and stable tuning. Built-In Automatic Modulation Control — ensures a constant RF modulation level. Repeater Offset — lets you select the appropriate offset value to match a local repeater.
MANUAL CONVENTIONS Some of your transceiver’s controls perform multiple functions. The abbreviation or symbol for a function is printed on, or above each multi-function button. To activate certain transceiver features, you must press F (function) and then another button. Those key combination instructions are printed as the first button name, +, then the second button name. For example, F+LOCK means press F then press LOCK. Control names are printed in small, bold, capital letters such as CALL or VFO.
CONTENTS Introduction to Amateur Radio ............................................. 7 Preparation ............................................................................. 9 Attaching the Microphone Holder ..................................... 9 Mounting the Transceiver ................................................. 9 Connecting an Antenna ................................................... 11 Connecting the Microphone ............................................ 12 Using an External Speaker .......
Other Special features ......................................................... Using Priority Frequency Monitor .................................... Using VFO Priority ................................................... Using Memory Priority .............................................. Changing the Transmit Frequency Range ...................... Selecting the Transmit Power Level ................................ Locking the Keypad .........................................................
INTRODUCTION TO AMATEUR RADIO This transceiver is the perfect first radio for anyone entering the exciting world of amateur radio, as well as a great additional transceiver for the experienced amateur radio operator. This transceiver opens a door for you to the world from almost anywhere! All you need is an Amateur Radio Operator’s License (Technician Class or higher) issued by the Federal Communications Commission (FCC).
Start studying for the license exams. Do not be intimidated by the word “study,” because most people can go from knowing absolutely nothing about amateur radio to passing the Novice and Technician written exams in less than a month. The exams test your knowledge of basic radio regulations and elementary radio theory. Many clubs hold license classes which can be a fun and easy way to learn about amateur radio. There are good books, cassette tapes, computer programs, and many other study aids available.
PREPARATION ATTACHING THE MICROPHONE HOLDER Follow these steps to attach the microphone holder to your vehicle. 1. Using the holder as a template, mark the position for the mounting screw holes at the desired location. 2. At each marked position, drill a hole slightly smaller than the supplied mounting screw. Caution: Be careful not to drill into anything behind the mounting surface. 3.
Caution: If you use the transceiver in a vehicle, mount it securely to avoid damage to the transceiver or vehicle, or injury to anyone in the vehicle during sudden starts or stops. Follow these steps to mount the transceiver. VO L OP SQ 1. Using the mounting bracket as a template, mark the positions for the screw holes on the mounting surface, 2. In each marked location, drill a hole slightly smaller than the supplied self-tapping screws.
CONNECTING AN ANTENNA You must install an antenna before you can operate the transceiver. There are many different types of antennas suitable for transceiver use. Each has its own benefits, Choose the one best suited to your particular needs. Your local RadioShack store has a wide selection from which to choose. Note: If you are using the transceiver as a base station, see “Using the Transceiver as a Base Station” on Page 13.
CONNECTING THE MICROPHONE 1. Align the notch of the microphone’s plug and the microphone’s jack, located on the left side of the front panel. Then insert the plug and turn the metal ring clockwise to secure the plug. MHz F L CALP STE N SCA PRI Lock FT SHI F ON DTM 2. Slide the microphone onto the microphone holder. To disconnect the microphone from the transceiver, turn the metal ring counterclockwise to loosen it. Caution: Always disconnect the microphone by grasping its plug.
CONNECTING POWER Follow these steps to power the transceiver from your vehicle’s battery. 1. Connect the supplied polarized 13.8V DC power connector to the white power socket and cable on the back of the transceiver. The plug and socket only fit one way. If you can not easily insert the plug, turn it over and try again. Do not force it. 2.
• a base station antenna • coaxial antenna cable and appropriate connectors Your local RadioShack store carries a wide selection of all products needed to set up your transceiver as a base station. Follow these steps to use the transceiver as a base station. 1. Mount the base station antenna as described in its owner’s manual. Warning: Use extreme caution when you install or remove a base station antenna. If the antenna starts to fall, let it go! It could contact overhead power lines.
A QUICK LOOK AT THE CONTROLS Most of the controls on the transceiver have multiple functions. The following charts should help you get a better idea of the function of each control. OFF/VOL SQ Tuning Control REV VFO MR (T-SQ) (MS) Base Unit Use with the F + Key to: Key/Control Use it to: OFF/VOL Turn the transceiver on/ off. Adjust the volume. Reset the transceiver SQ Set the squelch level to block weak signals. N/A Reverse the repeater offset.
CALL (STEP) DN SCAN (PRI) LOCK (SHIFT) UP F (MHz) PTT DTMF Microphone Use with the F + Key to: Key/Control Use it to: Push to Talk (PTT) Transmit by holding it down. Press to store a setting. Change the transmitting power to high or low. UP Increase the frequency by the selected step value. Increase the frequency in 1 MHz steps. DN Decrease the frequency by the selected step value. Decrease the frequency by 1 MHz steps. F (MHz) Temporarily open the squelch.
Microphone Key/Control SCAN (PRI) Use with the F + Key to: Use it to: Start and stop scanning. Set the transceiver to dual watch mode. LOCK (SHIFT) Lock and unlock the controls except PTT, F, VOL, and SQ. Set the repeater offset. AlphaNumeric Keys Enter numerical values and DTMF control letters. N/A Switch to DTMF control.
A QUICK LOOK AT THE DISPLAY 1. FUNC — appears when F key is pressed. 2. — indicates the keypad is locked. 3. — indicates a negative repeater offset. 4. — indicates a positive repeater offset. 5. SCAN — appears when the transceiver is scanning frequencies. 6. PRI — indicates a priority frequency. 7. T — appears when Tone Squelch (CTCSS) is enabled for transmission only. 8. T-SQ — appears when Tone Squelch (CTCSS) is enabled for both transmission and reception. 9.
OPERATION TURNING THE TRANSCEIVER ON AND OFF To turn on the transceiver, rotate VOL clockwise until it clicks. The last used frequency and other settings appear (the default frequency is 142.50 MHz, with a frequency step of 5 kHz/.005 MHz). To turn the transceiver off, rotate VOL counterclockwise until it clicks. SELECTING FREQUENCIES To select a frequency in the VFO (variable frequency oscillator) mode, use either UP or DN on the top of the microphone or the tuning control.
RECEIVING TRANSMISSIONS Follow these steps to receive standard transmissions. 1. With the transceiver on, rotate SQ counterclockwise until you hear a hissing sound. Then slowly rotate SQ clockwise just until the noise stops. Notes: • BUSY appears when the transceiver receives a standard transmission or if the squelch is open. • If the transceiver picks up unwanted and weak transmissions, rotate SQ clockwise to prevent the squelch from opening for these transmissions.
2. Hold the microphone about 3 inches from your mouth. 3. Hold down the ribbed transmit button on the side of the microphone, then speak slowly and clearly into the microphone. TX appears while you transmit, and signal strength bars appear on the bottom to indicate the relative transmitting signal output. Note: If you try to transmit outside the transmit frequency range, E appears instead of TX to indicate you are outside the transmitting range. 4. Release the transmit button when you finish transmitting.
UNDERSTANDING REPEATERS Operating through a repeater, where you transmit on one frequency and receive on another, is called duplex operation. Operating direct to another station, where you transmit and receive on the same frequency, is called simplex operation. A repeater is a station that receives a signal on one frequency (the input frequency) and then retransmits that signal on a different frequency (the output frequency).
SETTING THE REPEATER OFFSET FREQUENCY Note: This setting affects only the VFO mode. If you saved a repeater offset in a memory, that setting is not affected. 1. Press F+SHIFT (LOCK). The offset frequency and appear. 2. While the offset frequency appears, rotate the tuning control or repeatedly press UP or DN until the desired offset appears. The transceiver’s default repeater offset is 600 kHz, which appears as 0.60 (MHz). You can select a value from 100 kKz to 8.000 MHz. 3.
REVERSING THE TRANSMIT AND RECEIVE FREQUENCIES To swap the input and output frequencies, press REV. For example, if you have set the transceiver to repeater operation on 146.94 MHz with a positive offset of 600 kHz, the transceiver would normally receive on 146.94 MHz and transmit on 147.54 MHz. After you press REV, the transceiver is set to receive on 147.54 MHz and transmit on 146.94 MHz.
MEMORY OPERATION Your transceiver has 10 standard memory locations that you can use to store frequencies for quick access. You can also store other settings for each memory location, such as the repeater offset and the CTCSS tones. STORING A TRANSMIT/RECEIVE FREQUENCY 1. Select the frequency you want to store by using the tuning control or UP/DN. 2.
USING THE CALLING-FREQUENCY MEMORY The calling-frequency memory location lets you quickly jump to a specific programmed frequency at any time. The default calling frequency is 146.52 MHz. You can store a different frequency into memory as well as other settings associated with that frequency, such as the repeater offset and CTCSS tone. 1. Select the desired calling frequency using UP/DN or the tuning control. 2. Press F+MR (MS). A memory location and ME appear. 3.
SCANNING OPERATION SCANNING FOR ACTIVE FREQUENCIES 1. To search for activity on a frequency, press SCAN (PRI). SCAN appears. The transceiver begins to scan up or down the full frequency range. The transceiver stops on each active frequency for 5 seconds if squelch is on. If squelch is off, the transceiver stops on each location for about 1 second. 2. To change the scanning direction, press UP or DN. 3. To stop on a frequency or to stop scanning completely, press SCAN again.
CONTINUOUS TONE CODED SQUELCH SYSTEM FEATURES Your transceiver can transmit and receive a low-level, selectable subaudible tone at the same time as it transmits (TX) or receives (RX) a regular signal. This special tone lets you listen only to other transceivers set to the same tone frequency when you use the transceiver in simplex operation. It also lets you match your transceiver to the subaudible tone frequency used by a local repeater.
Subaudible Tone Frequencies (Hz) 67.0 107.2 167.9 71.9 110.9 173.8 74.4 114.8 179.9 77.0 118.8 186.2 79.7 123.0 192.8 82.5 127.3 203.5 85.4 131.8 210.7 88.5 136.5 218.1 91.5 141.3 225.7 94.8 146.2 233.6 97.4 151.4 241.8 100.0 156.7 250.3 103.5 162.
USING DTMF TONES DTMF (Dual-Tone, Multiple Frequency) is another term for touchtones (the tones a telephone produces when you press a digit). This standard set of tones is used by many different amateur transceiver systems for accessing programmable features and dialing through autopatches to a standard telephone. Your transceiver produces all 16 standard DTMF tones (0–9,*, #, A, B, C, and D). Follow these steps to use the DTMF feature. 1. Set DTMF on the bottom of the microphone to ON. 2.
OTHER SPECIAL FEATURES USING PRIORITY FREQUENCY MONITOR You can designate one frequency as primary (in either VFO or memory mode) and another frequency as secondary (VFO only). Once you do that, the transceiver tunes the primary frequency or memory location for 5 seconds. Then it checks the secondary frequency for 1/2 second. If the transceiver finds a signal on the secondary frequency, it automatically remains there for 5 seconds before returning to the primary frequency. Using VFO Priority 1.
CHANGING THE TRANSMIT FREQUENCY RANGE You can change the standard transmit frequency range from 144–148 MHz to an extended range of 142.000–149.885 MHz. To set the transceiver to its extended range, turn it off. Then while holding down F and LOCK, turn on the transceiver. To return to the standard frequency range, repeat the above procedure. SELECTING THE TRANSMIT POWER LEVEL You can select either of two transmitting power levels: high (25 watts) for normal operation or low (10 watts).
TURNING THE KEY TONE ON AND OFF The transceiver is preset to sound a beep each time you press a key. To turn off the beep, hold down the PTT button while you turn on the transceiver’s power. To restore the key tone, repeat the procedure. SETTING THE FREQUENCY STEP To change the frequency increment used during scanning and stepping to a frequency, press F+STEP (CALL). The current frequency step appears. Then repeatedly press UP or DN or rotate the tuning control to change the setting. The default is 5 kHz.
• Replace old ignition wires with new, high-voltage, noise suppression wires. • Install noise suppressors on your spark plugs, or install new spark plugs that have built-in noise suppressors. • If problems persist, check to ensure your alternator and electrical system are operating correctly. You can reduce any noise by using bypass capacitors at the various output voltage points. Your local RadioShack store carries a wide selection of capacitors and other appropriate noise reduction components.
TROUBLESHOOTING If your transceiver is not working as it should and it displays an error message, these suggestions might help you eliminate the problem. If the transceiver still does not operate properly, take it to your local RadioShack store for assistance. Symptom Problems with reception Possible Cause and Solution Squelch setting too high. Adjust as needed. Tuned to a non-operating frequency. Tune to an active frequency. Antenna not properly attached. Check and reconnect if needed.
CARE AND MAINTENANCE Your RadioShack 2-Meter FM Mobile Amateur Transceiver is an example of superior design and craftsmanship. The following suggestions will help you care for your transceiver so you can enjoy it for years. Keep the transceiver dry. If it gets wet, wipe it dry immediately. Liquids might contain minerals that can corrode the electronic circuits. Use and store the transceiver only in normal temperature environments.
RESETTING THE TRANSCEIVER If the transceiver’s display locks up or the transceiver does not work properly after you turn it on, you might need to reset it. Important: This procedure clears all the information you have programmed into the transceiver. Before you reset the transceiver, try turning it off then on again to see if it begins working properly. To reset the transceiver, turn it off then hold down F and turn it on again. All display elements appear, confirming the reset operation. Release F.
SPECIFICATIONS GENERAL Frequency: TX ................................................ 144.000–148.000 MHz Extended TX Range .................... 142.000–149.885 MHz RX ................................................ 136.000–174.000 MHz Frequency Control .......................... Digital PLL Synthesizer Display Type.................................................................. LCD Operating Temperature ................................... –4° to 122°F (–22.5° to 49.5°C) Power Requirements ..............
TRANSMITTER Max Power Output: High .................................................................. 25 watts Low .................................................................... 10 watts Spurious Emission .................................. Better than –65dB Deviation ................................................................. ± 5 kHz Battery Drain: High ............................................................................ 5A Low ............................................................
Limited One-Year Warranty This product is warranted by RadioShack against manufacturing defects in material and workmanship under normal use for one (1) year from the date of purchase from RadioShack company-owned stores and authorized RadioShack franchisees and dealers.
