Radio Shack 200 Owner's Manual download pdf (Page 27)

Guide to the Action Bands

462.9375–463.1875 ........................................................................................................... MED

463.200–467.925 ................................................................................................................ BUS

FM-TV Audio Broadcast, UHF Wide Band (470–512 MHz)

(Channels 14 through 20 in 6 MHz steps)

475.750 .................................................................................................................... Channel 14

481.750 .................................................................................................................... Channel 15

487.750 .................................................................................................................... Channel 16

493.750 .................................................................................................................... Channel 17

499.750 .................................................................................................................... Channel 18

505.750 .................................................................................................................... Channel 19

511.750 .................................................................................................................... Channel 20

Note:

Some cities use the 470–512 MHz band for land/mobile service.

AVOIDING IMAGE FREQUENCIES

You might discover one of your regular stations on another frequency that is not listed. It might

be what is known as an image frequency. For example, you might find a service that regularly

uses a frequency of 453.275 also on 474.675.

To see if it is an image, do a little math.

Note the new frequency. 474.675

Double the intermediate frequency of 10.7 MHz (21.400)

and subtract it from the new frequency. –21.400

If the answer is the regular frequency, 453.275

then you have tuned to an image.

Occasionally, you might get interference on a weak or distant channel from a strong broadcast

21.4 MHz above or below the tuned frequency. This is rare, and the image signal is usually

cleared whenever there is a broadcast on the actual frequency.

FREQUENCY CONVERSION

The tuning location of a station can be expressed in frequency (kHz or MHz) or in wavelength

(meters). The following information can help you make the necessary conversions.

1 MHz (million) = 1,000 kHz (thousand)

To convert MHz to kHz, multiply the number of MHz by 1,000:

30.62 MHz

1000 = 30,620 kHz

To convert from kHz to MHz, divide the number of kHz by 1,000.

127,800 kHz ÷ 1000 = 127.8 MHz

To convert MHz to meters, divide 300 by the number of MHz.

300 ÷ 50 MHz = 6 meters

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Radio Shack 200 Owner's Manual Page 27