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21-869.fm Page 1 Wednesday, October 13, 1999 11:50 AM
Cat. No. 21-869
10M Ham/CB Base Antenna
Your RadioShack 10M Ham/CB Base
IMPORTANT SAFETY
Antenna provides excellent reception of
PRECAUTIONS
amateur radio, CB, and commercial radio
signals. The antenna can handle up to
Many do-it-yourself and professional an-
2000 watts of transmit power.
tenna installers are injured or killed each
year by electric shock. Many power wires
Your antenna’s features include:
are within 20 to 25 feet of the gr
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21-869.fm Page 2 Wednesday, October 13, 1999 11:50 AM Coaxial Cable Installation BEFORE YOU BEGIN Precautions When deciding on an antenna’s location, consider these points: • Do not install coaxial cable where it will have a pulling tension of greater • The antenna should be as high as than 50 pounds. Leave no tension possible on the building. on the cable after installing it. • The antenna and its cable should be • Use only round-headed staples. as far as possible from sources of Any clamps
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21-869.fm Page 3 Wednesday, October 13, 1999 11:50 AM 2. Remove the cap from the top of the PREPARATION top element. 3. Use a tape measure to measure the Pre-Tuning the Antenna length you need to cut off of the top element, then use a hacksaw to Your antenna is preset to use 27.205 carefully cut the top element. MHz (the middle of the CB band) for the lowest SWR. If you are using your anten- 4. Replace the cap on the top element. na with a CB radio, you do not have to 5. Set the tuning rings
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21-869.fm Page 4 Wednesday, October 13, 1999 11:50 AM Follow these steps to assemble and mount the antenna. 1. Lay the antenna’s components on the ground in a flat, open area. 3 /8 2. Place the supplied -inch lock washer (2) over the threaded end of the top element (1). 3. Insert the threaded end of the top element into the threads on the center element (3), screw the top element into the center ele- 1 /2 ment, then use a -inch wrench to tighten it. 1 /2 4. Place the supplied -inch lock was
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21-869.fm Page 5 Wednesday, October 13, 1999 11:50 AM 4. Using an SWR meter, check the TUNING THE ANTENNA SWR at the top and bottom of the band. If the SWR is higher at the top If you are using your antenna at frequen- of the band than at the bottom, raise cies in the range of 25 to 30 MHz, you both tuning rings counterclockwise can tune the antenna using an standing- 1 1 at increments of /4 to /2 turns. wave ratio (SWR) meter (not supplied) and the dual tuning rings on the bottom 5. Repeat S
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21-869.fm Page 6 Wednesday, October 13, 1999 11:50 AM TROUBLESHOOTING If you have problems mounting or tuning your antenna, here are some suggestions that might help. If you still have trouble, contact your local RadioShack store for assistance. PROBLEM POSSIBLE CAUSE SOLUTION SWR reading is too Depending on the frequency you Pre-tune the antenna (see “Pre- high or cannot be set. want to use it for, the antenna Tuning the Antenna” on Page 3). might be too long or too short. The antenna is not
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21-869.fm Page 7 Wednesday, October 13, 1999 11:50 AM SPECIFICATIONS Reception ....................................................... VHF and UHF (Pre-tuned for 27.205 MHz) Half-Wave Gain ....................................................................................................... 9.9 dBi Optimum SWR Range ............................................................................... Less than 1.5:1 Height (assembled) ...............................................................
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21-869.fm Page 8 Wednesday, October 13, 1999 11:50 AM Limited Ninety-Day Warranty This product is warranted by RadioShack against manufacturing defects in material and workman- ship under normal use for ninety (90) days from the date of purchase from RadioShack company- owned stores and authorized RadioShack franchisees and dealers. EXCEPT AS PROVIDED HEREIN, RadioShack MAKES NO EXPRESS WARRANTIES AND ANY IMPLIED WARRANTIES, INCLUDING THOSE OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURP
