Sentry HO900 Owner's Manual - page 2

Important Safety Instructions:

Battery Installation:

What’s Included:

Transmitter Controls:

Headset Controls:

1) Headset Receiver

2) Transmitter

3) RCA to Phono Plug Adapter

4) Stereo Mini-Plug Adapter

5) Hi-Fi Stereo Adapter

6) Transmitter Cradle

(For use with optional 12V Power Adapter.   

Sold separately.)

Transmitter:

1) Telescopic Antenna 

2) OFF Button

3) ON Button 

4) LED Power Indicator

5) Audio Input Jack

6) Battery Compartment

Headset Receiver:

1) ON Button

2) OFF Button

3) Volume Control Dial

4) LED Power Indicator

5) Battery Compartment

6) Battery Compartment Latch

• To avoid injury to ears and stereo player, lower volume before plugging headphones into device. 

• It is not advisable to listen to headphones while cycling, driving a vehicle or operating machinery.  

• Avoid listening for prolonged periods at high volume which may damage hearing.

Transmitter:

1. Open up the battery compartment on the transmitter and insert one ‘9V’ battery. 

2. Replace the cover to the transmitter’s battery compartment by sliding it back on.

Headphone:

1. Open the battery compartment by sliding the latch downward. 

2. Put in two 'AAA' batteries. Make sure they are placed in the compartment with the polarity 

in the correct position (+/-).

3. Close the compartment by sliding the cover back on & closing the latch.

Using the Optional 12V Power Adapter:

The Transmitter can also be powered by an optional 12V Power Adapter. AC/DC Adapters are

sold separately and are available at most home electronics retailers or department stores. To

use the Power Adapter:

1. Place the Transmitter in the supplied Cradle. 

2. Connect the Power Adapter to the transmitter’s Cradle. 

3. Plug the Power Adapter into a nearby electrical outlet.

NOTE: Make sure the Power Adapter is the correct voltage and polarity as indicated on the 

cradle. Failure to do so may cause damage to the transmitter. 

If Something Doesn’t Sound Right:

If you experience static, distortion, or signal loss while listening to the Headphones:

1. Refer to the QUICK-START GUIDE and verify that all of your connections are correct.

2. Make sure that all connections are secure. 

3. Make sure the Transmitter is connected to the “Audio-Out” jacks of the source device.

4. Replace the batteries in either the Headset or the Transmitter.

5. Make sure that the source audio device is turned on and set to a reasonable volume.

6. Ensure that you are within approximately 100 feet of the Transmitter. 

Plugging in and Turning On:

Please refer to the QUICK-START GUIDE included with this product for detailed instructions 

on connecting the Transmitter to most commonly used audio devices.

1. Connect the Transmitter to the “Audio-Out” jacks of your audio device using the supplied 

cables and adapters. (NOTE: When connecting the Transmitter to a Television, the RCA 

“Audio-Out” jacks are located on the back of your TV Set, not the front).

2. Make sure that your audio device is turned on and set to a reasonable listening volume. 

3. Fully extend the Transmitter’s Telescopic Antenna.

4. Turn the Transmitter on by pressing the “On Button” located on top of the Transmitter.

5. Turn the Headset on by pressing the “On Button” located on the side of the Headset.  

6. Adjust the listening volume to a comfortable level using the Headset’s Volume Control Dial.