any semi conductor experts here? Guitar Guys?!

[phatdave]

Anybody know the technical aspect of Transistors? ie Germanium,silicon,mosfet,sft etc?

 

I bought a guitar pedal on Ebay. It was supposed to have a NOS Germanium trans. in it. The actual Trans. in it is marked SFT 306. It's noisy like a MudderFugger.

 

I know this isn't about Datsuns and most people on the board are more interested in bagging a truck or which Titan wheels will make their Truck look like a cartoon truck, or how to paint a Jap flag...but...

 

Somebody here probably nows a bunch about electronics. Your help would be appreciated. Really.

[edakotaford]

hah, sorry bro. i'ma drummer :D

[phatdave]

Drummer eh? What do you do when a drummer knocks on your front door? You pay him for the Pizzas....HAH!

 

I asked a drummer once to spell Mississippi...he asked me the River or the state? :D

[datzenmike]

Ah... I see you have a Stacking-Fault Tetrahedron STF 306.

[phatdave]

Not spin filter transistor?

 

Stacking fault tetrahedra..... although they have a peculiar structure, are the most general type of vacancy clustered defects in f.c.c. metals and alloys. Placing these stacking fault tetrahedra at the center, the story of point defect reaction is told...... The structure of the defect and the energy relation are first described. Various experimental treatments which lead to the formation of stacking fault tetrahedra are described, featuring characteristic point defect processes in each.......?! Quenching from high temperature leads to an understanding of the nucleation processes. Electron irradiation focuses on the relation with the local accumulation of vacancies, and the stochasticity of point defect reaction is detected in terms of the behavior of the defects during irradiation. Microstructural evolution by irradiation with neutrons and ions is well illustrated by the formation of stacking fault tetrahedra directly from collision cascades. Subcascade formation, estimation of deposited energy density, impact effect from cascade collision to point defect reaction, and roles of freely migrating point defects are included in the story related to the formation of stacking fault tetrahedra. Finally, plastic deformation, especially recent results on high-speed heavy deformation, presents the striking result of the formation of high density stacking fault tetrahedra even in pure aluminum, which leads to a proposal of plastic deformation without dislocation.

[Xnke]

Ge transistors are known for the noise characteristics. probably has tin whiskers growing in the can...this is a failure mode.

 

best shot at fixing it is this:

 

remove from circuit

charge a 100uF cap to 12-24V

tie all three active leads together, and short cap from leads to case.

 

This will blow out all the metal whiskers, and probably fix your problem. No guarantees, as I'm only familiar with the AF series Ge transistors.

[phatdave]

What about pulling the sft and putting in it's place an old OC ? or nkt,Sanyo, Raytheon, Germanium?

 

The treble boost is great but the noise is pretty loud. Thanks for your response, by the way.