Radio Shack HTX-242 manual

Cat. No . 19-1126 O WNER’S MANU AL HTX-242 T W O-METER MOBILE T RANS- CEIV ER Please read bef ore using this transceiver .[...]

2 Y our HTX-242 Two-Meter Mobile T ransceiver is an exciting addi- tion to Radio Shack’s growing line of high-quality amateu r 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. FEA TURES Auto[...]

3 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 fr om 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 (V ariable-Frequency Osc[...]

4 CONTENTS Installation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6 Unpacking the Transceiver . . . . . . . . . . . . . . . . . . . . . . . . . 6 Connecting the Microphone . . . . . . . . . . . . . . . . . . . . . . . . . 6 Mounting the HTX-242 in a Vehicle . . . . . . . . . . . . . . . . . . . 7 Connecting an Antenn[...]

5 Advanced Operation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 25 Frequency Offset Defaults . . . . . . . . . . . . . . . . . . . . . . . . . 25 Turning Auto Duplex On and Off . . . . . . . . . . . . . . . . 25 Changing the Default Offset . . . . . . . . . . . . . . . . . . . . 26 Reversing the Offset . . . . . . . . . . . . . . . .[...]

6 INSTALLATION Unpac king the T ransceiv er As you unpack the transceiver , check to be sure you have all the items shown in this illustration. Connecting the Micr ophone Plug the microphone’s connector into the microphone jack, secure the microphone holder to either the left or right side of th e trans- ceiver , then clip the microphone to the h[...]

7 Mounting the HTX-242 in a V ehicle When you select a mounting location for the HTX-242, be sure: • Y ou c an easily reach it • No wires or cables will interfer e with the vehicle’s operation • It is not directly in front of heating vents • All wires will reach their connection points Use the supplied screws, metal washers, bracket, rubb[...]

8 Connecting an Antenna Y ou can connect a variety of antennas for both mobile and base- station use (see “Using the HTX-242 as a Ba se 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 a ntenna and its loca- tion, consider the following: • The antenna[...]

9 Connecting to y our V ehic le’ s Po w er Follow these steps to power the HTX-242 in your vehicle. 1. Connect the black wire to your vehicle battery’s negative (–) ter minal or to a metal p art 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 o[...]

10 Using the HTX-242 as a Base Station Although we designed the HTX-242 primari ly for use as a mobile transceiver , you can also use it as a base station. To do so, you need these items: • 13.8-V olt DC regulated power supply that can supply at least 10 amps continuous power • Base station antenna • 50-ohm coaxial antenna cable and connecto [...]

11 Using the HTX-242 with P ack et Radio Y ou can connect your HTX-242 directly to a packet radio terminal node controller , a s shown below. Note: Y ou can purchase an 8-pin plug that matches your HTX- 242’s MIC jack at your local Radio Shack store (Cat. No. 279-4 40). Connecting an Exter nal Speak er (Optional) Y ou can connect an exter nal spe[...]

12 UNDER STANDING 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 (V ariable-Frequency Oscillator) modes let you directly select a frequency anywhere within the HTX-242’s o perating range. Y our HTX-242 has two VFOs[...]

13 Subaudible T one (CTCSS) F eatures 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 t h[...]

14 Under standing the Display One or more of the following indicators appear when you tur n 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 (tr ansmit on VFO-A and receive on VFO-B). See “Using the Dual V FOs for[...]

15 + or – — indicates the duplex offset dir ection. 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 — ind icates the transmit power level. See “Setting the Power Level” on Page 17. ON-AIR — appears when you transmit . See “T ransmittin[...]

16 BASIC OPERATION Tu r n i n g O n / O f f Y o u r H T X - 2 4 2 To tur n your HTX-242 on or of f, press PO WER . When you tur n 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 displ ays PLL Err or EEP Err , or if [...]

17 Setting V olume and Squelch SQUELCH sets the minimum signal level th at must be present for the HTX-242 to amplify the signal through the speaker or to stop when scanning. Follow these steps to set th e squelch. 1. Rotate SQUELCH fully counterclockwise. 2. Set VO L U M E so you can hear the background hiss between transmissions. Note: If you do [...]

18 Selecting a Frequenc y Y ou can select a frequency in any of three ways: • Direct entry • Tuning • Scanning Directly Entering a Frequenc y 1. Press VFO to select either VFO-A or VFO-B . 2. Enter the last five digits of the frequency. For example, t o enter 145.050, simply press 45050 . T uning to a Frequency 1. Press VFO to select either V[...]

19 Scanning f or a Frequenc y 1. Press VFO to select either VFO-A or VFO-B . 2. Press F . Then press ▲ to scan up or ▼ to scan down. Setting the Frequenc y Step The factory default frequency step is 20 kH z. Each time y ou rotate TUNE one click, or press UP or DO WN on the microphone, the fre- quency changes by 20 kHz. When scanning, the HTX-24[...]

20 Setting the Scan Options Stor ing Scan Skip Frequencies Y ou 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. F UNC flashes. 3. Press MR . The HTX-242 displays SC and the current scan r[...]

21 Setting the Scan Resume Delay When you set the scan resume condition to cr (carrier), the HTX- 242 resumes scanning after the carrier drops. The scan resume delay option lets you set the HTX-242 to pause bef ore resuming so you can hear replies. The factory default is 2 seconds. Follow these steps to change the scan resume delay. 1. Press VFO . [...]

22 Receiving T ransmissions To receive a transmission, tur n on the HTX-242, adjust the volume and squelch, and tune to the frequency you want to mo nitor . The HTX-242 displays BUSY , and the signal-strength indicator sh ows the relative signal strength when it receives a signal. Note: If BUSY appears but you hear nothing from the speake r , be su[...]

23 Manually T ransmitting DTMF T ones To transmit DTMF tones, follow the steps for transmitting. Then, while holding down P TT , press the digits on the microphone to transmit the tones. T ransmitting DTMF T ones fr om Memor y 1. Press DTMF so the HTX-242 displays DTMF and the current DTMF memory number . 2. To select a dif ferent DTMF memory, pres[...]

24 Limiting T ransmit Duration When you communicate on the 2-meter ban d, you should keep your transmissions as brief as possible. Mos t repeaters have built- in timers that limit single transmissions to 3 minutes or less. Y ou can set the transceiver to stop transmitting and sound a bee p if a single transmission exceeds the selected time (n one, [...]

25 ADV ANCED OPERATION Frequenc y Offset Def aults When you select a frequency, the HTX-242 defaults to th e following frequency of fsets if auto duplex is turned on: The default offset is 600 kHz. For example, if you tune to receive 146.940 MHz, the HTX-242 automatically tr ansmits at 146.340 MHz (600 kHz less than 146.940). T ur ning Auto Duple x[...]

26 Chang ing the Def ault Of fset Follow these steps to change the default offset for the VFO modes. 1. Press VFO . 2. Hold F for at least 1 second. F UNC flashes. 3. Press SHIFT . The HTX-242 displays oS and the current of fset (in MHz). 4. Rotate TUNE , press UP or DO WN on th e microphone, or directly enter the step using the microphone’s keyp[...]

27 Using the Dual VFOs f or Duple x Operation Follow these steps to use one VFO to transm it and the other to receive. 1. Press VFO to select VFO-A . 2. Select a frequency. 3. Press VFO to select VFO-B . 4. Select a frequency. 5. Press DUP . When the HTX-242 displays: VFO-A-T VFO-B it transmits on the VFO-A frequency and receives on the VFO-B frequ[...]

28 USING MEMOR Y CHANNELS The HTX-242 has 40 standard memory channels and on e calling- frequency memory, where you can store frequently-used frequen- cies, along with all settings, for quick access . Stor ing a Frequenc y 1. Press VFO and tune to a frequency you want to store. Set all duplex and subaudible ton e sett ings (see “Using Subaud ible[...]

29 7. Press ▲ . The HTX-242 displays rC and the current receive subaudible tone. 8. Rotate TUNE , or press UP or DO WN on the microphone, to change the receive subaudible tone. 9. Press ▲ . The HTX-242 displays tC and the current transmit subaudible tone. 10. Rotate TUNE , or press UP or DO WN on the microphone, to change the transmit subaudibl[...]

30 T uning to a Standard Memor y Channel 1. Press MR . 2. Rotate M-CH , or press UP or DO WN on the microphone, to select the desired memory channel. Using the Calling-Frequenc y Memor y Press CALL . The HTX-2 42 recalls all settings saved in the calling- frequency memory. Checking Prior ity Channel 1 To have the HTX-242 periodically “look back?[...]

31 Scanning Memor y Channels To set the HTX-242 to scan memory channels, press and release MR . Then press and hold MR for at least 1 second. . flash es, and the HTX-242 scans memories that have the scan option turned on (see “Enabling/Disabling Scanning for Mem ory Channels” on this page). The HTX-242 stops when it encounte rs a transmission. [...]

32 USING DTMF AND SUBAUDIBLE T ONES Y our HTX-242 has 10 DTMF (Dual-Tone, Multiple Frequency — another name for touch tones ) memories where you can store DTMF sequences. DTMF Memory 0 can hold a 7-digit DTMF paging sequence your HTX-242 must receive for DTMF paging. DTMF Memories 1-10 each hold 15 digits you can quickly transmit. Stor ing a DTMF[...]

33 Using DTMF P age DTMF page lets other operators page you. To turn on DTMF page, press DTMF so DTMF appe ars. The HTX-242 does not pass trans- missions to the speaker until it receives the sequence you stored in DTMF Memory 0. If DTMF Memory 0 is emp ty, DTMF page does not operate. When you receive a DTMF pag e, the HTX-242 turns on the speaker a[...]

34 • Assuming all club members have DTMF pag e activated, to page everyone, transmit 465ABC. • To page W est Side members, transmit 4654ABC. • To page Doug and Cary, transmit 46518ABC. • To page only one person, transmit the 7-digit sequence. Using A uto-Reply If you turn on the auto-reply feature, the HTX-242 automatically sends the sequen[...]

35 Using DTMF Auto Send If you turn on the DTMF auto-send feature, the HTX-242 automat- ically sends the sequence stored in the currently-selected DTMF memory every time you press P TT . Follow these steps to turn on auto send. 1. Press VFO . 2. Hold F for at least 1 second. F UNC flashes. 3. Press MR . 4. Repeatedly press ▲ to select the dA opti[...]

36 Using Subaudible T ones Some repeaters require you to transmit a subaudible tone to acti- vate them. Y ou can set your HTX-242 to transmit any of the 38 standard subaudible tones. Y ou can also limit incoming reception by setting the HTX-242 to open the squelch only when someone transmits a subaudible tone you select. V alid Subaudible T ones Se[...]

37 5. Press ▲ . The HTX-242 displays tC and the currently set transmit tone. 6. Rotate TUNE , or press UP or DO WN on the microphone, to set a differ ent transmit tone. If yo u do not want a transmit tone, select oFF . 7. Press T- S Q L or P TT to save the settings. Activ ating Subaudible T one T ransmit an d Squelch 1. Press T- S Q L once. T app[...]

38 USING THE MENU Y our HTX-242 has a menu that lets you select how some functions work. The previous sections included procedures that access this menu — this section provides an overview. Follow these steps to use the menu: 1. Press VFO . 2. Hold F for at least 1 second. F UNC flashes. 3. Press MR . The first menu item appears. Then press ▲ o[...]

39 Menu Item Default Option Explanation/Avai lable Settings Page # SC ti Scan resume option. ti — time out in 10 seconds. Cr — resume after carrier drops. SE — do not resume scanning. 20 Sd 2.0 Scan delay (delay before resume when SC is set to Cr ). 0.5 , 1 , 2 , or 4 . 21 S 1 –––.––– Scan skip frequency 1 (frequency for HTX-242 t[...]

40 T R OUBLESHOOTING Error Codes Y our HTX-242 has the following three built-in error codes. tF Err — appears if you try to transmit outside the allowed range (see “Extending the Transmit Frequency Range” on Page 16). PLL Err — appears if the HTX-242’s PLL (phase-locked loo p) sec- tion malfunctions. If turning the HTX-242 of f then back [...]

41 Replacing the Fuse Y our HTX-242 (and vehicle) are protected by a 15-amp fuse in the HTX-242’s positive (red) power wire. If the HTX-242 does not turn on, even when you are sure the power wire is properly connected to a 12V DC power source, check the fuse and replace it, if necessary. 1. Snap open the in-line fuse holder . 2. Remove the fuse f[...]

42 SPECIF ICATIONS General Frequency Range (Factory) T ransmit . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 144 – 148 MHz Receive. . . . . . . . . . . . . . . . . . . . . . . . 136.000 – 17 4.000 MHz Frequency Step . . . . . . . . . . . . . . 5/10/12.5/20/25/50/100 kHz Frequency Stability . . . . . . . . . . . . . . . . . . . . . .[...]

43 T ransmitter RF Power Output . . . . . . . . . . . . . . . . . . . 45 W (high)/10 W (Low) Maximum Deviation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5 kHz Hum and Noise . . . . . . . . . . . . . . . . . . . . . . . . Better than 35 dB Audio Distortion . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3% (TX) Au[...]

44 SCHEMATICS[...]

45 RF SCHEMATIC[...]

46 DIG ITAL SCHEMATIC[...]

47 MICR OPHONE SCHEMATIC[...]

Radio Shack A Division of T andy Corporation Fort W orth, T exas 76102 7A6 Printed in K ore a Radio Shack Limited W arranty This product is warranted against def ects for 1 y ear from date of purchase from Radio Shack company-o wned stores and authorized Radio Shack franchisees and dealers. Within this period, we will repair it without charge for p[...]