1. Product Overview
The KELUSHI C019 is a smart and lightweight telephone line tester designed for telecommunication professionals and enthusiasts. It provides essential functions for checking telephone lines, including Caller ID display, redial capabilities, and various connection options. Its compact design makes it suitable for field use and computer lab environments.

Figure 1: KELUSHI C019 Telecom Check Telephone Line Tester
2. Key Features
- Smart and Lightweight Design: Optimized for portability and ease of use in various settings.
- FSK / DTMF Dual System Caller ID: Supports both FSK and DTMF Caller ID formats for broad compatibility.
- Multiple External Plug Heads: Includes three types of external plug heads for versatile connection options.
- Take-Function (Line Function): Enables specific line operations.
- Last Group Dial Number Redial Function: Allows for quick redialing of the most recently dialed number.

Figure 2: KELUSHI C019 Tester with highlighted functions
3. Package Contents
Verify that all items are present in the package:
- KELUSHI C019 Host Unit x 1
- Straight Line Cable x 2
- Straight-Through Head Adapter x 1
- Product Packaging Box x 1

Figure 3: KELUSHI C019 Product List

Figure 4: KELUSHI C019 Shipping Styles (Note: Two styles may be shipped randomly)
4. Setup and Connections
To set up your KELUSHI C019 tester, identify the appropriate connection method for your task:
- Direct Line Connection: Use one of the provided straight line cables to connect the tester directly to a telephone wall jack or a compatible port.
- Alligator Clip Connection: For connecting to bare wires or terminals, attach the alligator clips to the straight line cable or use the dedicated alligator clip adapter if provided. Ensure proper polarity when connecting.
- Straight-Through Head: Utilize the straight-through head adapter for specific testing scenarios where a pass-through connection is required.
Ensure all connections are secure before proceeding with any tests or operations.

Figure 5: KELUSHI C019 Connection Cables and Alligator Clips
5. Operating Instructions
The KELUSHI C019 is designed for straightforward operation. Familiarize yourself with the keypad and display for optimal use.
5.1 Basic Operation
- Power On/Off: Use the designated ON/OFF button to power the device.
- Making a Call: Dial the desired number using the numeric keypad.
- Redial: Press the 'REDIAL' button to call the last dialed number.
- Flash Function: Use the 'FLASH' button for specific telephone system functions, such as call waiting or transferring.
5.2 Caller ID
When connected to a line with Caller ID service, incoming call information (number, name if available) will be displayed on the LCD screen. The device supports both FSK and DTMF Caller ID systems.
5.3 Line Testing
The C019 can be used to check for line presence and basic continuity. Observe the display and listen for dial tone to confirm line status. For detailed line diagnostics, consult advanced telecommunication testing procedures.

Figure 6: KELUSHI C019 Keypad Detail

Figure 7: KELUSHI C019 Earpiece/Microphone
6. Maintenance
To ensure the longevity and proper functioning of your KELUSHI C019 tester, follow these maintenance guidelines:
- Cleaning: Wipe the device with a soft, dry cloth. Avoid using harsh chemicals or abrasive cleaners.
- Storage: Store the tester in a cool, dry place away from direct sunlight and extreme temperatures.
- Battery: The device requires Nonstandard Battery batteries. Replace batteries as needed to maintain optimal performance. Refer to the battery compartment for specific battery type and replacement instructions.
- Cable Care: Avoid sharp bends or excessive pulling on the coiled cord and connection cables to prevent damage.
7. Troubleshooting
If you encounter issues with your KELUSHI C019 tester, try the following steps:
- No Power: Ensure batteries are correctly installed and have sufficient charge. Replace batteries if necessary.
- No Dial Tone/Line Signal: Check all cable connections to the telephone line and the tester. Ensure the line itself is active.
- Caller ID Not Displaying: Verify that your telephone line service includes Caller ID. Ensure the connection is secure.
- Buttons Unresponsive: Power cycle the device (turn off and on). If the issue persists, check for physical damage.
For persistent issues not resolved by these steps, please contact customer support.
8. Specifications
| Feature | Specification |
|---|---|
| Model Number | C019 (FBA_KLSC019) |
| Brand | KELUSHI |
| Dimensions | 16.1 x 5.8 x 5.4 cm |
| Item Weight | 133 Grams |
| Material | Plastic, Metal |
| Power Source | Corded Electric (requires Nonstandard Battery batteries) |
| Telephone Type | Corded |
| Dialer Type | Single Keypad |
| Answering System Type | Digital |
| Caller ID | Yes (FSK / DTMF dual system) |
| Compatible Devices | Telephone Line, Computer |
| Multiline Operation | Single-Line Operation |
| Phone Standby Time | 5 minutes |

Figure 8: KELUSHI C019 Dimensions and Basic Specifications
9. Warranty and Support
For warranty information, technical support, or service inquiries, please refer to the contact details provided with your purchase or visit the official KELUSHI website. Keep your purchase receipt as proof of purchase for warranty claims.
10. Additional Details

Figure 9: KELUSHI C019 Hanging Buckle Design for Portability

Figure 10: KELUSHI C019 Cable Tester in Use