20-430.fm Page 16 Wednesday, August 4, 1999 1:29 PM

UNDERSTANDING

BANKS

Channel Storage Banks

To make it easier to identify and select the channels you want to listen to, channels are divided into 10 banks of 30 channels each. Use each channel- storage bank to group frequencies, such as those used by the police de- partment, fire department, ambulance services, or aircraft (see “Guide to the Action Bands” on Page 39). For exam- ple, the police department might use four frequencies, one for each side of town. You could program the police frequencies starting with Channel 1 (the first channel in bank 1) and pro- gram the fire department frequencies starting with Channel 31 (the first channel in bank 2).

Service Banks

The scanner is preprogrammed with the frequencies allocated by public safety, police, fire/emergency, aircraft, and weather services. This is handy for quickly finding active frequencies instead of searching through an entire band (see “Searching Service Banks” on Page 18).

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UNDERSTANDING

TRUNKING

In the past, groups that broadcast fre- quently, such as police departments, were restricted to transmitting on just a few frequencies. This resulted in heavy traffic and often required 2-way radio users to wait for a specific fre- quency to clear before transmitting.

Trunked systems allow more groups of 2-way radio users to use fewer fre- quencies. Instead of selecting a spe- cific frequency to transmit on, a trunked system chooses one of sever- al frequencies when the 2-way radio user presses PTT (push to talk). The system automatically transmits the call on that frequency, and also sends

acode that identifies that 2-way radio user’s transmission on a data channel.

You can set this scanner to monitor the data channel frequency, so you can hear both the call and response transmissions for that 2-way radio user and therefore follow the conver- sation. (You cannot listen to the data channel itself in the trunk mode.)

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Radio Shack PRO-2050 owner manual Understanding Banks, Understanding Trunking, Channel Storage Banks, Service Banks