How to Read CRT Tube Part Numbers

Written by Jestine Yong

All picture tubes, whether monochrome or color type are identified by a specific code consisting of numbers and letters. The codes are different from each other because different tubes have different characteristics.

For example, a certain monitor colour picture tube may haverepparttar designation, M34AFA63X03 that can breakdown into 6 parts: M/34/AFA/63/X/03

Part 1: Application

Computer monitor tubes start withrepparttar 138982 letter "M” while for a TV picture tube, it start with “A”.

Part 2: Screen diagonal measure in centimeters (cm)

The “34” meansrepparttar 138983 diagonal viewing measure is a minimum of 34cm which refers to 14” tube, 36cm is 15”, 41cm is 17” and so on.

Part 3: Family code

The three letters “AFA” designate a family of tubes that have similar physical and electrical characteristic. These letters are assigned alphabetically beginning with “AAA”, followed by “AAB”, “AAC” etc.

Part 4: Family number

The number 63 shows a specific tube withinrepparttar 138984 family code. A different number is assigned to tubes withinrepparttar 138985 same family that have different neck diameters, for example a single digit would be a monochrome tube, but this two-digit number shows it is colour.

Understanding Transistor Data and Replacement

Written by Jestine Yong

If, for some reason, you can’t get an exact replacement forrepparttar transistor that you want to replace, you can refer to one ofrepparttar 138981 transistor substitution guides or book, and try to identify a “near replacement”. Beware, however. A substitution guide will sometimes list a replacement for your part, even thoughrepparttar 138982 two parts are not very similar. The most commonly used transistor substitution guides isrepparttar 138983 Philips ECG semiconductors Master Replacement Guide. Selectingrepparttar 138984 right transistor parameters or specifications forrepparttar 138985 equipment you repair will avoid callbacks from customers. Callbacks or repeated repairs due to wrong transistor substitution will cost you extra money and a waste of time.

Some important transistor parameters are:

Maximum collector-to-base voltage (VCBO) – The replacement part should have a VCBO rating equal to or higher thanrepparttar 138986 original.

Maximum collector-to-emitter voltage (VCEO) – The replacement part should have a VCEO rating equal to or higher thanrepparttar 138987 original.

Maximum emitter-to-base voltage (VEBO) – The replacement part should have a VEBO rating equal to or greater thanrepparttar 138988 original.

Maximum collector current (IC) – The replacement part should be able to handle as much (or more) collector current asrepparttar 138989 original.

Power dissipation (PD Watts) – The replacement part should be able to dissipate as much (or more) power asrepparttar 138990 original part.

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