- DL manuals
- Radio Shack
- Measuring Instruments
- 21-534
- Owner's Manual
Radio Shack 21-534 Owner's Manual
Summary of 21-534
Page 1
Cat. No. 21-534 owner’s manual please read before using this equipment. Cb/high-frequency ham power swr meter 21-534.Fm page 1 thursday, august 5, 1999 3:53 pm downloaded by amateur radio directory.
Page 2: Introduction
© 1998 tandy corporation. All rights reserved. Radioshack is a registered trademark used by tandy corporation. 2 introduction your radioshack cb/high-frequency ham power swr meter helps you tune your cb or amateur radio system for the best performance. Cb and amateur radio systems work best when the...
Page 3: Contents
3 contents measuring swr . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4 connecting the meter . . . . . . . . . . . . . . . . . . . . . . . . . . 4 calibrating the meter/measuring swr . . . . . . . . . . . . . 5 interpreting swr readings . . . . . . . . . . . . . . . . . . . . . ...
Page 4: Measuring Swr
4 measuring swr measuring swr shows you how much of your radio’s transmit power is reflected from the antenna back into the antenna ca- ble, generating heat and wasting power. With this information, you can adjust the length of your antenna or antenna cable so your antenna and radio combination can ...
Page 5
5 1. Turn off your radio. Then disconnect the antenna from the radio and plug it into antenna on the back of the meter. 2. Plug the coaxial cable into the radio’s antenna jack and into transmitter on the back of the meter. Calibrating the meter/ measuring swr 1. Turn on your radio. Then set function...
Page 6
6 notes: • an swr reading will be different for different frequen- cies (channels). If you transmit on one channel more often than any other, select that channel. If you trans- mit on several channels, choose a frequency in the middle of the range of channels you use. (for example, if you transmit o...
Page 7
7 4. Release the transmit key, then set function to swr . 5. Press the transmit key again, then find the swr by read- ing the appropriate scale on the meter. • if your transmitter’s power is less than 20 watts, read the lower scale (marked with an l on its right side) • if your transmitter’s power i...
Page 8
8 interpreting swr readings an ideal swr reading is 1.0, but this reading is usually possi- ble only under laboratory conditions or with a dummy load. Ac- tual antenna installations have higher readings. The in- formation below will help you interpret the readings you get. Swr efficiency interpretat...
Page 9
9 when you measure swr, use this chart to determine the per- centage of power that is wasted through reflection of the signal back to the radio. For example, an swr reading of 1.5 also means that 4% of your signal power is lost. However, 96% of the radio’s power is more than enough for almost all ap...
Page 10
10 • adjust the length of your antenna according to the instruc- tions provided by the manufacturer. A change of as little as 1 / 8 inch can make a measurable difference. • see your radio and antenna’s owner’s manuals. 21-534.Fm page 10 thursday, august 5, 1999 3:53 pm.
Page 11: Measuring Power
11 measuring power you can use your meter to show how much power your radio is transmitting. You can use this information with the swr reading (see “measuring swr” on page 4) to determine the efficiency of your antenna and radio combination, or to make sure that your antenna and radio combination ar...
Page 12
12 • if your transmitter’s power is 20 watts or less, set range to 20w . • if your transmitter’s power is more than 20 watts but 200 watts or less, set range to 200w . • if your transmitter’s power is more than 200 watts, or you do not know the transmitter’s power, set range to 2000w . 3. Set mode o...
Page 13
13 4. If your transmitter does not use ssb, select a channel or frequency on your transmitter and hold down its transmit key. Do not speak into the microphone. If your transmitter uses ssb, input a 1000–1500 hz tone signal from the low-frequency oscillator you connected to the transmitter. Then, sel...
Page 14: Care And Maintenance
14 care and maintenance your radioshack cb/high-frequency ham power swr meter is an example of superior design and craftsmanship. The following suggestions will help you care for your meter so you can enjoy it for years. Keep the meter dry. If it gets wet, wipe it dry im- mediately. Liquids can cont...
Page 15
15 modifying or tampering with your meter’s internal components can cause a malfunction and might invalidate the meter’s war- ranty. If your meter is not operating as it should, take it to your local radioshack store for assistance. 21-534.Fm page 15 thursday, august 5, 1999 3:53 pm.
Page 16: Schematic Diagram
16 schematic diagram notes: 1. All resistance values are indicated in “ohm” (k=10 3 ohm). 2. All capacitance values are indicated in “ m f” (p=10 - 6 m f). 3. All diodes ( ) indicated in 1k100-350. (illus - show schematic diagram of meter) 21-534.Fm page 16 thursday, august 5, 1999 3:53 pm.
Page 17: Specifications
17 specifications measurable rf power ...................................... 1–2000 watts swr: at 25 ohms load impedance ...................................... 2.0 at 50 ohms load impedance ...................................... 1.1 at 100 ohms load impedance .................................... 2.0...
Page 18: Notes
18 notes 21-534.Fm page 18 thursday, august 5, 1999 3:53 pm.
Page 19
19 limited ninety-day warranty this product is warranted by radioshack against manufacturing defects in ma- terial and workmanship under normal use for ninety (90) days from the date of purchase from radioshack company-owned stores and authorized ra- dioshack franchisees and dealers. Except as provi...
Page 20
Radioshack a division of tandy corporation fort worth, texas 76102 811081270a 3a8 printed in china (continued) this warranty does not cover: (a) damage or failure caused by or at- tributable to acts of god, abuse, accident, misuse, improper or abnormal usage, failure to follow instructions, improper...