RadioShack FM Mobile Transceiver HTX 252 Owners Manual

							31
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 fre-
quency for 
1/2 second. If the transceiver finds a signal on the sec-
ondary frequency, it automatically remains there for 5 seconds
before returning to the primary frequency.
Using VFO Priority
1. Select the desired secondary frequency using the tuning
control or 
UP/DN. 
2. Press 
F+PRI (SCAN)
3. Select the primary frequency using the tuning control or UP/
DN. The transceiver starts to monitor both selected frequen-
cies.
4. To disable priority monitor, press 
F+PRI (SCAN) again.
Using Memory Priority
1. Select the desired secondary VFO frequency using the tun-
ing control or 
UP/DN. 
2. Press 
F+PRI (SCAN)
3. Press MR (MS) then select the desired memory location for
your primary frequency. The transceiver starts to monitor
both selected frequencies.
4. To disable priority monitor, press 
F+PRI (SCAN) again. 
						

							32
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 pro-
cedure.
SELECTING THE TRANSMIT POWER 
LEVEL
You can select either of two transmitting power levels: high (25
watts) for normal operation or low (10 watts). Choose the lower
level to reduce the possibility of overloading nearby receivers.
Choose the higher level when conditions warrant maximum
transmitting power. To switch levels, press 
F+PTT. If low is select-
ed, 
LOW appears. If high is selected, LOW disappears.
LOCKING THE KEYPAD
To lock the transceiver’s keypad so you do not accidentally
change a setting, press 
LOCK (SHIFT).   appears. This locks all
controls except 
PTT, F, VOL, SQ, and LOCK. 
To unlock the keypad, press 
LOCK again. 
						

							33
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 fre-
quency step appears. Then repeatedly press 
UP or DN or rotate
the tuning control to change the setting. The default is 5 kHz. You
can change the frequency step to 5 kHz, 10 kHz, 12.5 kHz, 15
kHz, 20 kHz, or 25 kHz.
REDUCING INTERFERENCE
Because your transceiver is exceptionally quiet, any noise you
hear probably originates from a source within your vehicle such
as the alternator, the spark plugs, or unshielded wires.
To solve the problem, you must locate the noise’s source. You
can determine the noise’s source by first turning off the engine
and operating the transceiver with your vehicle’s ignition set to
ACC. If the noise decreases or disappears completely, the prob-
lem is with your vehicle’s ignition or associated wiring.
Here are a few suggestions to help you reduce or eliminate such
noise:
• Make all of the transceiver’s power and antenna wires as
short and as direct as possible.
• Route the power wires away from the antenna wires.
• Be sure the chassis ground connection is secure. 
						

							34
• Replace old ignition wires with new, high-voltage, noise sup-
pression 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 capaci-
tors and other appropriate noise reduction components. 
						

							35
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 Possible Cause and Solution
Problems with reception
Squelch setting too high. 
Adjust as needed.
Tuned to a non-operating fre-
quency.
Tune to an active frequency.
Antenna not properly attached.
Check and reconnect if needed.
Poor antenna cable connec-
tions. Check connections and 
repair or replace as needed.
Problems with transmis-
sionPoor antenna cable connec-
tions. Check connections and 
repair or replace as needed. 
Check all connections for corro-
sion and clean if necessary.
PTT button not fully pressed. 
Press firmly and hold down when 
transmitting.
Microphone connection loose. 
Secure the connection.
No Power
Check fuse. Replace if blown.
Check power cables and con-
nections. Repair or replace if 
broken or disconnected. 
						

							36
CARE AND MAINTENANCE 
Your RadioShack 2-Meter FM Mobile Amateur Transceiver is
an example of superior design and craftsmanship. The follow-
ing 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 tem-
perature environments. Temperature extremes
can shorten the life of electronic devices, dam-
age batteries, and distort or melt plastic parts.
Keep the transceiver away from dust and dirt,
which can cause premature wear of parts.
Handle the transceiver gently and carefully.
Dropping it can damage circuit boards and cases
and can cause the transceiver to work improper-
ly.
Wipe the transceiver with a damp cloth occasion-
ally to keep it looking new. Do not use harsh
chemicals, cleaning solvents, or strong deter-
gents to clean the transceiver.
Modifying or tampering with the transceiver’s internal compo-
nents can cause a malfunction and might invalidate its war-
ranty and void your FCC authorization to operate it. If your
transceiver is not performing as it should, take it to your local
RadioShack store for assistance.  
						

							37
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 transceiv-
er, try turning it off then on again to see if it begins working prop-
erly.
To reset the transceiver, turn it off then hold down 
F and turn it on
again. All display elements appear, confirming the reset opera-
tion. Release 
F.
REPLACING THE IN-LINE FUSE
The transceiver (and vehicle) are protected by a 10-amp fuse in
the transceiver’s positive (red) power wire. If the transceiver does
not turn on, check the fuse and replace it to be certain.
Follow these steps to check or replace the fuse, 
1. Make sure the transceiver is off.
2. Snap open the in-line fuse holder by applying thumb pres-
sure in opposite directions on the seam lock.
3. Remove the fuse from the holder and slide the fuse out of
the end connectors.
4. If the fuse’s filament is blown, replace the fuse with one of
the same type and rating. Then snap the cover closed. 
						

							38
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  ............................................ 13.8V DC 
(12–16V DC, negative ground)
Antenna  ...................................  50-ohm (coaxial connector)
Dimensions (HWD) ........................  1
1/4 × 53/25 × 51/2 inches
  (32 × 130 × 140 mm)
Weight  ............................................................................  1.54 lb.
(0.7 kg)
RECEIVER
Sensitivity  .........................................  0.22 µV for 10 dB S/N
Overload Audio Fidelity @ 6dB Down ............. 450–2100 Hz
Adjacent Channel Selectivity  .....................................  60 dB
Spurious and Image Rejection  ........................... 60 dB Min.
Maximum Audio Output Power......  2.5 watts @ 8-Ohm load
Squelch Tight Range  ....................................  0.5 m to 1 mV
Battery Drain:
No Signal ............................................................ 300 mA
Maximum Output ................................................ 600 mA 
						

							39
TRANSMITTER
Max Power Output:
High  ..................................................................  25 watts
Low  .................................................................... 10 watts
Spurious Emission ..................................  Better than –65dB
Deviation  .................................................................  ± 5 kHz
Battery Drain:
High ............................................................................ 5A
Low .............................................................................. 3A
Specifications are typical; individual units might vary. Specifica-
tions are subject to change and improvement without notice. 
						

							RadioShack
A Division of Tandy Corporation
Fort Worth, Texas 76102
02A00 Printed in Korea
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 Ra-
dioShack franchisees and dealers. EXCEPT AS PROVIDED HEREIN, Ra-
dioShack MAKES NO EXPRESS WARRANTIES AND ANY IMPLIED
WARRANTIES, INCLUDING THOSE OF MERCHANTABILITY AND FIT-
NESS FOR A PARTICULAR PURPOSE, ARE LIMITED IN DURATION TO
THE DURATION OF THE WRITTEN LIMITED WARRANTIES CON-
TAINED HEREIN. EXCEPT AS PROVIDED HEREIN, RadioShack SHALL
HAVE NO LIABILITY OR RESPONSIBILITY TO CUSTOMER OR ANY
OTHER PERSON OR ENTITY WITH RESPECT TO ANY LIABILITY, LOSS
OR DAMAGE CAUSED DIRECTLY OR INDIRECTLY BY USE OR PER-
FORMANCE OF THE PRODUCT OR ARISING OUT OF ANY BREACH
OF THIS WARRANTY, INCLUDING, BUT NOT LIMITED TO, ANY DAM-
AGES RESULTING FROM INCONVENIENCE, LOSS OF TIME, DATA,
PROPERTY, REVENUE, OR PROFIT OR ANY INDIRECT, SPECIAL, IN-
CIDENTAL, OR CONSEQUENTIAL DAMAGES, EVEN IF RadioShack
HAS BEEN ADVISED OF THE POSSIBILITY OF SUCH DAMAGES.
Some states do not allow limitations on how long an implied warranty lasts
or the exclusion or limitation of incidental or consequential damages, so the
above limitations or exclusions may not apply to you.
In the event of a product defect during the warranty period, take the product
and the RadioShack sales receipt as proof of purchase date to any Ra-
dioShack store. RadioShack will, at its option, unless otherwise provided by
law: (a) correct the defect by product repair without charge for parts and la-
bor; (b) replace the product with one of the same or similar design; or (c) re-
fund the purchase price. All replaced parts and products, and products on
which a refund is made, become the property of RadioShack. New or re-
conditioned parts and products may be used in the performance of war-
ranty service. Repaired or replaced parts and products are warranted for
the remainder of the original warranty period. You will be charged for repair
or replacement of the product made after the expiration of the warranty pe-
riod.
This warranty does not cover: (a) damage or failure caused by or attribut-
able to acts of God, abuse, accident, misuse, improper or abnormal usage,
failure to follow instructions, improper installation or maintenance, alter-
ation, lightning or other incidence of excess voltage or current; (b) any re-
pairs other than those provided by a RadioShack Authorized Service
Facility; (c) consumables such as fuses or batteries; (d) cosmetic damage;
(e) transportation, shipping or insurance costs; or (f) costs of product re-
moval, installation, set-up service adjustment or reinstallation.
This warranty gives you specific legal rights, and you may also have other
rights which vary from state to state.
RadioShack Customer Relations,200 Taylor Street, 
6th Floor, Fort Worth, TX 76102
We Service What We Sell12/99