dot on germanium transistor

Frequently asked question on transistors: types, substitutions, how to test, use and misuse them.

dot on germanium transistor

Postby copachino » 13 May 2014, 21:02

what does it mean a red dot on the transistors?? i have seen many dealers that says that their transistor have a red dot, but im not sure what ir means
Solder Soldier
Posts: 162
Joined: 14 Sep 2013, 00:53
Has thanked: 6 times
Have thanks: 6 times

Re: dot on germanium transistor

Postby tonyharker » 14 May 2014, 09:37

A red dot or other colour dot on the side of the transistor case ONLY denotes the collector lead.
A red spot elsewhere on older transistors - usually on the top - used to indicate the goodness/gain/frequency response of the device. There were red spots - the best, white spots - good, and unmarked low gain. The manufacturing processes of early transistors was not as exact/precise as modern ones.

For this message the author tonyharker has received thanks:
Intripped (15 May 2014, 06:38)
Posts: 44
Joined: 23 Jun 2011, 22:50
Has thanked: 8 times
Have thanks: 11 times

Return to Transistors

Who is online

Users browsing this forum: No registered users and 1 guest