Transistor matching tester....help needed

[peth]

Hi,

I am constructing a Bedini SG and need help with the transistor tester I have constructed it and the meter needle does not budge no matter where I have the pot set or with the 27k resistor bypassed. I measured the voltage between the push button switch and the base of the transistor that will vary between 12 volts and 11.70 depending on the pot setting. I even tried reversing the transistor and the needle will move and the transistor will heat up. I can take a picture of what I have built.

Thanks

Ian

[Ed_Morbus]

Ian can you make picture

[peth]

Here are a couple of pics

[peth]

am having trouble uploading pics will keep tying

[peth]

I have tried again to post a couple of pics but I get this red icon come up......,some kind of error message what other ways can I send you a pic

Ian

[peth]

Lets hope this the pics tried another method
Ian

[BobZilla]

Ian,
Sorry I can't help with your transistor matching but how did you fix your picture upload? I am having the same problem on my post.

[peth]

Hi Bob,
Yes it was a bit of a pain for as I have not been on forums for a while click in the immage icon that brings up a box with options, in the bottom right hand corner there is a "basic uploader" that is what I ended up using.

Ian

[BobZilla]

Testing upload pic



*Edit*

Many thanks Ian,,worked like a charm!

[guyzzemf]

I cant tell from you pics but it looks wrong to make things easier ..leave out meter and push button switch
if you flipped the transistor it may be bad
i dont see a ne2
more pics will be helpful
i dont see any diodes either
if you are building a trans tester then disregard all i said
i test trans with dmm https://www.youtube.com/watch?v=b0jCUsenNsY
if you have a diagram of what you are building post it

[peth]

I have tried a number of different new transistors the diagram is in the bedini manual

[peth]

previous was wrong pic

[guyzzemf]

iv never built that. it looks straight fwd ck a few transistor with d meter ck ur build/ then with a good transistor ck build
be sure u build it exactly as it is ,use cheap transistors
do u need to match gain for a multi transistors build ,if u havent built a single transistors [1 power 1 trigger] ssg yet [u should ]
if u just need to ck trane use dmm


https://www.youtube.com/watch?v=JLXKffm7VF4

https://www.youtube.com/watch?v=BgT9-VRf1Cw

[peth]

I began to experiment substuting resistors instead of the pot and found if I had a resistance of 19k the meter would give a reading of about 40ma if I went a couple of thousand ohms each way needle of the meter droped way back to very little. seems to be a narrow sweet spot.
Ian

[guyzzemf]

IAN
There are many diy transistor testers out there with instructions ,or for sale cheap
i have no experience with transistor matching . but i hear you will go through a lot of transistors to get a few that match
guy