Transistor Germanium oxidation

[andregarcia57]

hey guys.
I have some germanium transistors with oxidation on the terminals, and the cover also has a little oxidation.
I'm currently scraping the terminals with a craft knife.
The question is... is there any product that helps remove oxidation without damaging the transistor?
grateful

[theehman]

I just use some steel wool. Pinch the leads in the wool and move the transistor back and forth.

[Manfred]

I use a fiberglass pen to remove oxide layers from connecting leads and solder lugs.

[bumblebee]

#1000 wet and dry sand paper. (Used dry, of course)

[APMT]

The question is... is there any product that helps remove oxidation without damaging the transistor?

Yes, basic flux.

[mozz]

They don't look bad at all. I second the steel wool. When they get really bad they fall off.

[Vitallka]

You can also use a pencil eraser. This is the safest means for cleaning contacts. Ammonia can also be used for cleaning, but it must be washed off

[andregarcia57]

I ended up using steel wool and it turned out really well! without any chemicals. Thanks for the tip!

Moving on to the next conversation, do GE transistors increase leakage after being soldered?

What is the ideal temperature for soldering a GE transistor?

Currently my soldering iron is 30w, without a soldering station.
hugs

[Manfred]

It is recommended to leave the lead wires longer and to fit a crocodile clip or similar between the transistor and the soldering points for heat dissipation .
I only solder germanium transistors with leaded solder because it requires a lower temperature.

[andregarcia57]

It is recommended to leave the lead wires longer and to fit a crocodile clip or similar between the transistor and the soldering points for heat dissipation .
I only solder germanium transistors with leaded solder because it requires a lower temperature.

wow, thanks for another tip, I've normally used it
Lead Free 0,5mm
99,3 Sn (estanho)
0,7 Cu (Cobre)
I bought it on sale.

but I have a 60x40 solder tube here that should be better for germanium. what is the percentage of your weld? What is the good initial temperature for soldering germanium?
thanks!

[mozz]

Get in get out. I've never used a heat sink on transistors to solder. If the solder isn't taking, you have corrosion, old solder, or not enough temp. I think my Weller's are set at about 750f. 63/37 is a bit better than 60/40 because of the liquid to solid state is faster.

As to the leakage, the heat causes a temporary increase. If it has changed a lot, you have damaged the part.

[Manfred]

It is recommended to leave the lead wires longer and to fit a crocodile clip or similar between the transistor and the soldering points for heat dissipation .
I only solder germanium transistors with leaded solder because it requires a lower temperature.

wow, thanks for another tip, I've normally used it
Lead Free 0,5mm
99,3 Sn (estanho)
0,7 Cu (Cobre)
I bought it on sale.

but I have a 60x40 solder tube here that should be better for germanium. what is the percentage of your weld? What is the good initial temperature for soldering germanium?
thanks!

Use a different soldering tip for leaded solder.

[andregarcia57]

It is recommended to leave the lead wires longer and to fit a crocodile clip or similar between the transistor and the soldering points for heat dissipation .
I only solder germanium transistors with leaded solder because it requires a lower temperature.

wow, thanks for another tip, I've normally used it
Lead Free 0,5mm
99,3 Sn (estanho)
0,7 Cu (Cobre)
I bought it on sale.

but I have a 60x40 solder tube here that should be better for germanium. what is the percentage of your weld? What is the good initial temperature for soldering germanium?
thanks!

Use a different soldering tip for leaded solder.

I understand there is this more detail... important
in the first research one indicates this

[Manfred]

I am sorry, I did not express myself exactly.
I did not mean the type and size of the soldering tip, but a soldering tip that has not yet been used for lead-free solder.
The two types of solder do not harmonize with each other and it can lead to a bad solder joint .

[andregarcia57]

I am sorry, I did not express myself exactly.
I did not mean the type and size of the soldering tip, but a soldering tip that has not yet been used for lead-free solder.
The two types of solder do not harmonize with each other and it can lead to a bad solder joint .

I understand my friend... I also carried out welding tests here, I measured before and after welding and in general there was an increase in leakage of 5mA in the soldered transistor without a heatsink.

[RuptorGB]

I measured before and after welding and in general there was an increase in leakage of 5mA in the soldered transistor without a heatsink.

Did you measure the can & room ambient temperature as any temperature difference will affect the transistor and test circuit? I know it sounds pedantic but It comes from a job I did on testing the temperature stability of doped resistors for Harrier Jump Jets back in the day. Germanium leakage goes up with temperature I think from memory so the transistor junctions should be at the same temperature when measured.