The Sencore TR139 service manual provides detailed instructions for setting up and operating the in-circuit transistor tester, including how to connect the device to transistors and diodes for accurate testing of AC beta and leakage. It also offers troubleshooting guidance, highlighting the importance of beta and leakage measurements and ensuring that no damage occurs to components if the device is improperly connected.
Manual Overview
The Sencore TR139 Transistor Tester is designed for both in-circuit and out-of-circuit testing of transistors and diodes. It is particularly useful for measuring AC beta and leakage, which are critical parameters for assessing transistor performance. The device features a large 6-inch meter for easy readings and is housed in a durable vinyl-clad steel case. For troubleshooting, the TR139 provides accurate diagnostics by checking transistors for AC beta and leakage, and diodes for shorts and opens. It uses a NPN-PNP switch to select the correct polarity for testing, and an Off-Beta-Leakage switch to choose between different testing modes. The Beta Cal Control is crucial for adjusting readings to account for internal impedance differences in transistors. When connecting the tester, leads are attached to the collector, base, and emitter of the transistor. The manual emphasizes that improper connections will not damage components unless left for extended periods. For calibration, the TR139 requires adjustments for each transistor type to ensure accurate readings. The manual advises consulting a transistor specifications manual for precise beta and leakage values.
Quick Issues Covered
- Diagnose AC beta and leakage issues in transistors.
- Calibrate using Beta Cal Control for accurate readings.
- Use schematics for circuit tracing and connection guidance.
Overview
The Sencore TR139 is an in-circuit transistor tester designed to check transistors directly in the circuit, making it a time-saving tool for servicemen, labs, and production lines. It is capable of accurate out-of-circuit testing for transistors and diodes as well. The TR139 can test high and low power transistors for AC beta and leakage, and diodes and rectifiers for opens and shorts. It features a large meter for easy viewing and is housed in a modern vinyl-clad steel case. The device is designed to be versatile and cannot become obsolete.
Specifications
- Transistor Test
- Beta (hfe) measured at f=60 cycles, Ic=2.0MA, Vce=10V
- Range Beta. Accuracy
- LO 2-100 ±5%
- HI 16-500 ±5%
- Leakage (Icbo) measured at Vce=4V, Ib=0
- One range 0-100 microamps lower 1/2 of scale.
- 100-5000 microamps upper 1/2 of scale.
- Diodes and Rectifier Testing:
- In-circuit – checked for shorts and opens, can be detected with loads of 20 ohms paralleling the device.
- Out of circuit – checked for forward to reverse current ratio
- Electrical
- 117V AC 60Hz 2.5 watts
- Physical
- Dimensions – 9-1/2" high x 7-1/2" wide x 6" deep
- Weight – 7 pounds
Controls & Indicators
NPN-PNP Switch: Selects the proper polarity of DC voltage for testing transistors and diodes.
Off-Beta-Leakage Switch: Turns power off and selects Beta or Leakage range.
Beta Test Switch: Used for checking the beta of a transistor.
Beta Cal Control: Adjusts for accurate beta reading.
Test Jacks: Connect to the emitter (black), base (yellow), and collector (red) of the transistor.
Installation / Setup
Refer to the PDF for details.
Operation
The TR139 In-Circuit Transistor Tester is designed for testing transistors both in-circuit and out of circuit. It checks high and low power transistors for AC beta and leakage, as well as diodes and rectifiers for opens and shorts. The tester features a large meter for easy viewing and is housed in a modern vinyl-clad steel case. It includes controls such as an NPN-PNP switch for selecting the proper DC voltage polarity, an Off-Beta-Leakage switch for selecting test ranges, a Beta Test switch for checking transistor beta, and a Beta Cal control for adjusting readings. Test jacks are provided for connecting to the emitter, base, and collector of the transistor. The TR139 is versatile and can be used in design, production, or servicing of transistorized equipment, providing measurements of AC beta and leakage, which are critical parameters for transistors.
Troubleshooting & Error Codes
Refer to the PDF for details.
Safety & Warnings
Refer to the PDF for details.
Download 2 Service manual (PDF – 459.2 KB)
Sencore TR139 Transistor Tester Model 2 manual: troubleshoot, calibrate, and service operations. PDF size: 459.2 KB.
- Brand: Sencore-tr139-transistortester-operation-service-manual
- Model: 2
- Type: Service manual
- File size: 459.2 KB
Overview
Brief overview of the product.
Specifications
- Key spec 1
- Key spec 2
Controls & Indicators
Control panel/button layout.
Installation / Setup
- Step 1…
- Step 2…
Operation
Basic usage, modes, cycles.
Troubleshooting & Error Codes
| Issue / Code | Fix |
|---|---|
| Example | How to fix… |
Safety & Warnings
- Important warning…
Downloads
Download 2 service manual (PDF)
Sencore TR139 Transistor Tester Overview
The Sencore TR139 Transistor Tester is a precision diagnostic tool designed for testing and analyzing transistors and other semiconductor devices. It provides accurate measurements of transistor parameters, helping technicians and engineers quickly identify faulty components and verify device functionality. This tester is essential for electronics repair, manufacturing, and quality control applications.
Main Features and Specifications
- Tests NPN and PNP transistors, diodes, and other semiconductor devices
- Measures gain (hFE) and leakage current
- Easy-to-read analog meter display for quick diagnostics
- Compact and portable design for field and bench use
- Operates on standard batteries for convenient power supply
- Simple push-button operation for device selection and testing
Basic Usage and Operation Tips
To use the Sencore TR139, first ensure the device is powered with fresh batteries. Insert the transistor or semiconductor device into the appropriate test socket according to its type (NPN or PNP). Press the corresponding test button to initiate measurement. Read the analog meter to determine the gain and leakage characteristics. For accurate readings, make sure the test leads and sockets are clean and free of corrosion. Always consult the manual for specific device pin configurations before testing.
Troubleshooting and Maintenance
If the tester does not power on, check and replace the batteries as needed. Ensure all connections and test sockets are clean and intact. If readings appear erratic or inconsistent, clean the contacts with a suitable electronic contact cleaner. Avoid exposing the tester to moisture or extreme temperatures to maintain accuracy. Periodic calibration by a qualified technician is recommended to ensure continued reliable performance.
Safety Reminder
Always disconnect the device under test from any power source before testing to prevent damage or injury. Handle the tester and semiconductor devices with care to avoid electric shock or component damage. Use the tester only as described in the manual and store it in a dry, safe location when not in use.