TC1 tester readings

[pcb rookie]

I've been using the TC1 tester to check all components in preparation for all my builds. The res and caps is pretty strait forward.

As for the transistors, I have been measuring/using the hFE but the tester also providing the Ube (mV) and Ic (mA). If we use use 2N5088 for example. Does it provide me with the leakage? Are Ube and Ic relevant data I should consider when mesearing Transistors?

hFE = 586
Ube = 669mV
Ic = 2.9mA
(VBat@4.11v)

https://media.digikey.com/pdf/Data%20Sheets/ON%20Semiconductor%20PDFs/2N5088,%205089%20Rev3.pdf

Same goes for diodes, in this case i'm totally confused when trying to compare reading measures to the data sheet or vF provided by the seller to see if it fall with in expected tolerance. Also trying to identify what relevant in the case of pedal circuit.

BAT46
Uf = 375mV
C = 10pF
Ir = 78nA

www.digikey.ca/en/products/detail/stmicroelectronics/BAT46/691867

1N34A (STI)
Uf = 419mV
Ir = 0.55uA

sold as Vf .25. - .27 range - 60v, 30mV

www.pedalhackerelectronics.com/1N34A-NOS-Germanium-Diode-ITT-1N34-p/1n34a-10itt.htm

 

[fig]

Hi,

A 2N5088 is s silicon transistor and therefore will not have leakage. Germanium transistors do.

Silicon diodes will usually have an average value for forward voltage, but again germanium is unstable so it can vary with temperature, age, and the breakdown of the insulator (someone check me on that statement).
You usually match a germanium sample to a circuit rather than the other-way-round.

 

[pcb rookie]

Hi,

A 2N5088 is s silicon transistor and therefore will not have leakage. Germanium transistors do.

Good point! So let take GT404B transistor for examples. Here are the readings I'm getting from TC1. Is the leakage Ice?

hFE = 91
Une = 118mV
Ic = 1.2mA
Ibe = .26m
Ices=14uA

 

[Big Monk]

Good point! So let take GT404B transistor for examples.

Iceo will be leakage for a germanium on the TC1.

The accuracy is pretty darn good under 100 microamps leakage but starts to deviate from the R.G. Keen Method at around 150 microamps or so.

 

[fig]

I concur with Mr. Monk.

 

[pcb rookie]

So in the case of the reading I get from the GT404B (14uA) is very low right as target is to be under 300 ... i'm I being correct?

hFE = 91
Une = 118mV
Ic = 1.2mA
Ibe = .26m
Ices=14uA

 

[fig]

Is the target in uA or mA?

 

[fig]

Don't handle the transistors prior to measuring...or wait a couple minutes before measuring. They are very sensitive to temperature change, which is part of their charm and usefulness in a guitar pedal.

 

[pcb rookie]

Is the target in uA or mA?

I read my last message and I not even certain I understand my own questions ....so please allow me re-phrase it:

I'm I right to assume that 14uA is low when it comes to transistors leakage? What would be considered a usable leakage range for germanium transistor in general?

 

[Big Monk]

I read my last message and I not even certain I understand my own questions ....so please allow me re-phrase it:

I'm I right to assume that 14uA is low when it comes to transistors leakage? What would be considered a usable leakage range for germanium transistor in general?

Yes. That’s very low.

 

[Barry]

I read my last message and I not even certain I understand my own questions ....so please allow me re-phrase it:

I'm I right to assume that 14uA is low when it comes to transistors leakage? What would be considered a usable leakage range for germanium transistor in general?

Usable range is a loaded question, some circuits require leaky transistors, others not so much, when using GE Transistors, you need to know the circuits requirements

 

[pcb rookie]

Ok so i'm good as far as transistors go but for diodes, I'm still confused on what I should be interpreting our find relevant out of the readings on the TC1 when trying to compare either to the data sheet or the Vf value on the sellers web site. I hope my questioning ain't silly!

BAT46 TC1 readings : Uf = 375mV / C = 10pF / Ir = 78nA

www.digikey.ca/en/products/detail/stmicroelectronics/BAT46/691867

1N34A (STI) TC1 readings: Uf = 419mV / Ir = 0.55uA

"sold as Vf .25. - .27 range - 60v, 30mV"

www.pedalhackerelectronics.com/1N34A-NOS-Germanium-Diode-ITT-1N34-p/1n34a-10itt.htm

Usable range is loaded question, some circuits require leaky transistors, others not so much, when using GE Transistors, you need to know the circuits requirements

got it! That's clear! Thanks!

 

[Barry]

Ok so i'm good as far as transistors go but for diodes, I'm still confused on what I should be interpreting our find relevant out of the readings on the TC1 when trying to compare either to the data sheet or the Vf value on the sellers web site. I hope my questioning ain't silly!

BAT46 TC1 readings : Uf = 375mV / C = 10pF / Ir = 78nA

www.digikey.ca/en/products/detail/stmicroelectronics/BAT46/691867

1N34A (STI) TC1 readings: Uf = 419mV / Ir = 0.55uA

"sold as Vf .25. - .27 range - 60v, 30mV"

www.pedalhackerelectronics.com/1N34A-NOS-Germanium-Diode-ITT-1N34-p/1n34a-10itt.htm

got it! That's clear! Thanks!

Measure Vf with a multimeter not the TC1

 

[pcb rookie]

Measure Vf with a multimeter not the TC1

Got it! My DMM doesn't have a diode mode so this just got bump up on my list! Anyone as a DMM model to recommend?

 

[fig]

There are several that have been suggested (I think it's on the tool thread). I'd make certain it's a 1MΩ input impedance (not 10MΩ).

Again, I agree with Mr. Monk & Barry on their points.