I’m building a small kit radio, just as Shango066 did on his YouTube channel for those of you who watch him. I’m stuck on these last two transistors. They have no markings other then they both have a yellow dot on the back and one has a yellow dot on the top and one a green dot on top. I know that they’re both KT3107, but it appears there are different ones.
Dan
Dan
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Oh wow thank you, that helps quite a bit. I can tell that one of those sections is gain. Testing on a Peak Atlas DCA75 (which measures at lower voltages so gains will be lower) I get these.
Green dot on top has hfe of 45
Yellow dot on top has hFE of 138
So is it safe to say that the one with the green dot is the one that ends in E and the yellow is the one that ends with the X symbol with a line down the center?
Dan
Green dot on top has hfe of 45
Yellow dot on top has hFE of 138
So is it safe to say that the one with the green dot is the one that ends in E and the yellow is the one that ends with the X symbol with a line down the center?
Dan
color — цвет
red — красный (masc.), красная (fem.), красное (neut.)
orange — оранжевый (masc.), оранжевая (fem.), оранжевое (neut.)
yellow — жёлтый (masc.), жёлтая (fem.), жёлтое (neut.)
green — зелёный (masc.), зелёная (fem.), зелёное (neut.)
dark blue — синий (masc.), синяя (fem.), синее (neut.)
light blue — голубой (masc.), голубая (fem.), голубое (neut.)
purple — фиолетовый (masc.), фиолетовая (fem.), фиолетовое (neut.)
pink — розовый (masc.), розовая (fem.), розовое (neut.)
brown — коричневый (masc.), коричневая (fem.), коричневое (neut.)
black — чёрный (masc.), чёрная (fem.), чёрное (neut.)
white — белый (masc.), белая (fem.), белое (neut.)
light — светлый (masc.), светлая (fem.), светлое (neut.)
dark — тёмный (masc.), тёмная (fem.), тёмное (neut.)
red — красный (masc.), красная (fem.), красное (neut.)
orange — оранжевый (masc.), оранжевая (fem.), оранжевое (neut.)
yellow — жёлтый (masc.), жёлтая (fem.), жёлтое (neut.)
green — зелёный (masc.), зелёная (fem.), зелёное (neut.)
dark blue — синий (masc.), синяя (fem.), синее (neut.)
light blue — голубой (masc.), голубая (fem.), голубое (neut.)
purple — фиолетовый (masc.), фиолетовая (fem.), фиолетовое (neut.)
pink — розовый (masc.), розовая (fem.), розовое (neut.)
brown — коричневый (masc.), коричневая (fem.), коричневое (neut.)
black — чёрный (masc.), чёрная (fem.), чёрное (neut.)
white — белый (masc.), белая (fem.), белое (neut.)
light — светлый (masc.), светлая (fem.), светлое (neut.)
dark — тёмный (masc.), тёмная (fem.), тёмное (neut.)
Oh awesome, that helps confirm my thoughts! So the color green starts with the backwards “E” which is equivalent to E in English. The color yellow starts with the “X” looking character. I suspected that the green dot had the lower gain and is the KT3107E and the yellow is the other.
Dan
I get rid of all soviet transistors many years ago and use BC546/547/BC556/557 instead (or any other similar jellybean type).
There were several different marking types of KT3102/3107, so even I (born in the USSR/Ukraine Soviet Republic) can't get the exact type from your photo at the moment. They are a bit confusing, it can be KT3102/3107/KT502 etc.
