Germanium substitutes…

[Plaidesaurus]

I don’t have any experience with germanium transistors. I understand that the hfe/gain needs to be staged upward from Q1 - Q3 but I have a couple of questions.

I’ve got a cheap T7 tester but that will not give me those values. Should I get a Peak DCA55?

Due to so many of these transistors being hard to find I see a number of members say “any germanium” will do. Maybe this applies mostly to diodes but I’m walking in the dark. Can someone give me some input here?

Thx

 

[drgonzo1969]

I bought a dca55 a few months ago. No regrets. Great tool to have in your arsenal. Worth the investment

 

[spi]

If you use sockets or build on a breadboard you can just swap 'em and see which sounds best to you. For example, I found I liked the tonebender mk3 when I put the lowest gain in Q2, which is not the usual recipe.

Also, I measured the gain and hfe of mine using this technique http://www.geofex.com/Article_Folders/ffselect.htm

 

[Cybercow]

If you have a PC and would like see/visualize the trace curves on BJTs, diodes & such, get the Peak Atlas DCA75 - it comes with a bit of software for the PC run trace-curves on such devices. Either the DCA55 or DCA75 is a great investment if you're serious about building and learning electronics.

 

[jwin615]

Also, I don't think the 55 measures fets.

 

[Cybercow]

Also, I don't think the 55 measures fets.

The Peak Atlas DCA55 does do JFETs, but only identifies the Gate because JFETs are symmetrical - meaning the Source & Drain are interchangeable.

 

[swelchy]

if your already spending money towards the 55 I think the 75pro is the way to go... NO Regarts here..

 

[Kroars]

You can get hfe and leakage from a $20 TC1 tester. As a plus, they test closer to the voltages we see in our builds, as opposed to the DCA75, which tests a bit hotter.

https://a.co/d/eGIdimb

 

[knappster]

You can get hfe and leakage from a $20 TC1 tester. As a plus, they test closer to the voltages we see in our builds, as opposed to the DCA75, which tests a bit hotter.

https://a.co/d/eGIdimb

was going to post this, I bought the $20 tc-1 after buying a $40 tester lol

 

[joelorigo]

was going to post this, I bought the $20 tc-1 after buying a $40 tester lol

I will second this suggestion. I bought the TC1 and event though it has been said it may not as accurate as the more expensive ones, it is good for getting ranges in comparing transistors. And it seems pretty accurate when measuring caps and resistors compared to my DMM.

 

[jwin615]

You can get hfe and leakage from a $20 TC1 tester. As a plus, they test closer to the voltages we see in our builds, as opposed to the DCA75, which tests a bit hotter.

https://a.co/d/eGIdimb

Technically you get hFE, not hfe...
I wish there was a cheap and easy way to get hfe readings.

 

[Kroars]

Technically you get hFE, not hfe...
I wish there was a cheap and easy way to get hfe readings.

My apologies. I rarely speak (or type) technically.

 

[jessenator]

If you're into experimenting a bit, there's biggybacking, both to approximate/simulate germanium and reducing gain.

And here are a couple of external threads on the subject which have more detail. Definitely something to do on the breadboard first.

 

[Feral Feline]

Fixed a few anomalies...








Can you spot them all?

[PS: added another couple tweaks I missed the first time ]

 

[jessenator]

Typographical changes aside, you've completely removed the Torgo Tone out of the equation.

C1 iS a SMOOthing CAp to mIMICk GE transISTor higH-frEQUENcy RoLl-ofF



Now I want to make a pedal called the Torgo Tone. Or that should be the name of my company…

 

[jwin615]

Typographical changes aside, you've completely removed the Torgo Tone out of the equation.

C1 iS a SMOOthing CAp to mIMICk GE transISTor higH-frEQUENcy RoLl-ofF

View attachment 90695

Now I want to make a pedal called the Torgo Tone. Or that should be the name of my company…

Deep cut