background image

5

PREPARATION

Caution:

 

Make all the necessary connections before you plug in 

or turn on the receiver.

POSITIONING SPEAKERS

Speaker (not supplied) placement can make a noticeable 
difference in your system’s sound. The guidelines in this 
section will help you choose the best locations. After you use 
your receiver for a while, you might want to try different 
locations for your speakers.

Bass response depends largely on speaker location. For strong 
bass, place the speakers in the corners of the room. If you want 
even stronger bass, place the speakers directly on the floor. If 
the bass is too strong, move the speakers slightly away from 
the corners of the room, or raise them 6 to 18 inches off the 
floor. You can buy speaker stands at your local RadioShack 
store.

The distance between the speakers should be about the same as 
the distance between the normal listening point and the point 
halfway between the speakers. If you place the speakers too 
close together, you reduce the stereo separation. If you place 
them too far apart, you reduce the bass effect and create a hole 
in the middle of the sound.

Most speakers have a tweeter dispersion angle of about 60 
degrees. Ideally, your listening position should be just inside 
the overlap area of the tweeter dispersion. You can angle the 
speakers toward you for better stereo effect.

CONNECTING SPEAKERS

Follow these guidelines when you select and connect speakers.

• Only connect speakers that are rated at between 8 and 16 

ohms.

• Be sure you properly connect all speakers.

• Do not connect two pairs of speakers to a single set of 

terminals (A or B) at the same time. When you use two 
pairs of speakers, connect one pair to the A SPEAKERS 

terminals and the other pair to the B SPEAKERS 
terminals.

• Optimus, and other high-quality speakers have color-

coded speaker terminals (red for positive polarity and 
black for negative polarity). Use these color-coded 
terminals as a guide to help you properly connect the 
speakers to the receiver.

Use 16-gauge (or larger) speaker wire for all speaker 
connections, and consider possible speaker locations before 
you decide how much speaker wire you need.

Preparing the Speaker Wires

Speaker wire consists of two conductors (individual wires) 
encased in insulation and is usually color-coded or marked 
with a ridge along one side so you can identify each conductor. 
Use these markings as a guide to help you properly connect the 
speakers to your receiver.

Follow these steps to prepare the speaker wires.

1. Cut the speaker wires to the necessary length.

2. Separate the wires about 4 inches on each end.

3. Using a wire stripper, carefully strip about 

3

/

4

 inch of 

insulation from the end of each conductor.

4. Twist the end of each conductor to secure any loose wire 

strands.

Caution: Twisting the end of each conductor helps prevent 
a short circuit because stray speaker wire strands do not 
touch other speaker terminals or any other receiver 
terminals.

Connecting Speakers to the A and B Terminals

Note:

• Be sure you connect the receiver’s right and left positive 

(+) and negative (–) terminals to the speaker’s 
corresponding right and left positive (+) and negative (–) 
terminals.

• Fully insert the speaker wires to ensure a good connection. 

Leave extra wire at the back of the receiver so you do not 
disconnect the wires when you move the receiver.

Follow these steps to connect each speaker (

A

 right or left or 

B

 

right or left).

1. Press open the receiver’s positive (

+

) red lever for the 

speaker you want to connect and insert the ridged or color-
coded conductor’s end into the small hole. Release the 
lever to secure the conductor.

Summary of Contents for STA-3850

Page 1: ...owner s manual STA 3850 STEREO RECEIVER ...

Page 2: ...k for extended periods FCC NOTICE This system complies with the limits for a Class B digital device as specified in Part 15 of FCC Rules These limits provide reasonable protection against radio and TV interference in a residential area However your equipment might cause TV or radio interference even when it is operating properly To eliminate interference you can try one or more of the following co...

Page 3: ...ord Power Cord Protection Route power supply cords so they are not likely to be walked on or pinched by items placed on or against them paying particular attention to cords at plugs convenience receptacles and the point where they exit from the product Lightning For added protection for this product during a lightning storm or when it is left unattended and unused for long periods of time unplug i...

Page 4: ...ntrol s Batteries 8 Connecting to AC Power 8 Operation 9 Using the Sleep Timer 9 Tuning the Radio 9 Manual and Automatic Tuning 9 Direct Tuning Remote Control Only 10 Memory Tuning 10 Automatically Storing Stations 10 Manually Storing a Station 10 Tuning to a Station in Memory 10 Adjusting Balance 11 Muting the Receiver 11 Using Headphones 11 Listening Safely 11 Cassette Deck Features 11 Using the...

Page 5: ...and the other pair to the B SPEAKERS terminals Optimus and other high quality speakers have color coded speaker terminals red for positive polarity and black for negative polarity Use these color coded terminals as a guide to help you properly connect the speakers to the receiver Use 16 gauge or larger speaker wire for all speaker connections and consider possible speaker locations before you deci...

Page 6: ...und wire to the receiver s GND screw terminal Connecting a CD Player To connect a CD player to the receiver connect the CD player s left and right output jacks to the receiver s L and R CD IN jacks Connecting a Cassette Deck You can connect a cassette deck to the TAPE MONITOR jacks Connect the cassette deck s output jacks to the PLAY jacks and connect the cassette deck s input jacks to the REC jac...

Page 7: ...se only or an outdoor VHF TV antenna To connect the TV antenna to the receiver you need a VHF UHF FM splitter not included RadioShack stores carry a full line of quality antennas and antenna connection accessories Warning To prevent injury read and follow all cautions and warnings that accompany the outdoor antenna For the best radio reception use an outdoor antenna Follow these steps to connect a...

Page 8: ...he battery compartment cover push the compartment s tab in the direction of the arrow then lift off the cover 2 Place two fresh AA batteries in the compartment as indicated by the polarity symbols and marked inside 3 Replace the battery compartment cover Note If the remote s range is reduced replace the batteries CONNECTING TO AC POWER Warning To prevent electric shock do not use this polarized pl...

Page 9: ...u can use VOLUME and on the remote control 5 To adjust the tone turn BASS and TREBLE toward or To increase the high and low ranges of sound at low volume press LOUDNESS To turn off this feature press LOUDNESS again 6 To adjust the balance of sound between the left and right speakers see Adjusting Balance on Page 11 7 When you finish using the receiver press POWER to turn it off USING THE SLEEP TIM...

Page 10: ...st frequency station in the band Repeat these steps to automatically store stations in the other band Manually Storing a Station When the receiver automatically stores stations some of them might not be your favorites Or the 30 channel memory might have filled up before the receiver reached your favorite station at the high end of the frequency range Follow these steps to manually replace a statio...

Page 11: ...the volume level so a volume level that does not cause discomfort might still damage your hearing CASSETTE DECK FEATURES You can connect a cassette deck to the receiver Selecting TAPE MONITOR lets you hear the playback from the cassette deck you connected to the receiver s TAPE MONITOR jacks Using the Tape Monitor Button Press TAPE MONITOR TAPE MON appears along with the last program source you se...

Page 12: ...ne of the speaker wires or the input cord is disconnected Check all connections BALANCE is set too far to one side Set BALANCE to the center position High noise level Station not correctly tuned Adjust tuning Antenna not connected Connect the antenna FM antenna still coiled or is not pointing in the correct direction Stretch both ends of the antenna taut and reposition the antenna AM loop antenna ...

Page 13: ...hack and is covered by a limited warranty from RadioShack If your receiver is not operating as it should take it to your local RadioShack store or call 1 800 THE SHACK for assistance THE FCC WANTS YOU TO KNOW Your receiver might cause radio or TV interference even when it is operating properly To determine whether your receiver is causing the interference turn off your receiver If the interference...

Page 14: ...B FM Tuner Frequency Range 87 5 to 108 MHz Usable Sensitivity Mono 15 µV m EMF Signal to Noise Ratio Mono 68 dB Stereo 63 dB Distortion Stereo 0 5 1 kHz Alternate Channel Selectivity 45 dB 400 kHz Stereo Separation 35 dB 1 kHz AM Tuner Frequency Range 530 to 1720 kHz Sensitivity IHF Loop Antenna 500 µV m Selectivity 25 dB Signal to Noise Ratio 35 dB General Power Requirements 120 Volts AC 60 Hz Po...

Page 15: ...15 NOTES ...

Page 16: ...nt of a product defect during the warranty period take the product and the RadioShack sales receipt as proof of purchase date to any RadioShack store RadioShack will at its option un less otherwise provided by law a correct the defect by product repair without charge for parts and labor b replace the product with one of the same or similar design or c refund the purchase price All replaced parts a...

Reviews: