Rangemaster build problem

[Herec]

Hey,
I'm building an PNP Rangemaster

I used the NPN perfboard layout that I found but converted it to PNP (made the ground negative, turned around the capacitors) and it is not working.



To measure the voltages I had the black lead (common) touching the negative side of the battery (the negative ground) and touched each lead of the transistor with the red lead.

Here are the voltage readings

C = 1.98

B = 7.87

E = 8.02

The readings are the same whether or not I switch the two DMM leads around, and I didn't think I was supposed to have negative voltages.
I do not have a footswitch wired in.

I am going to try building a whole different unit using Dragon's stripboard layout, that should work.

!ALSO!

I have axial 47uF capacitors. The "crimped" end (the one with the little ball) is the positive side, correct?

Thank you.

[Dragonfly]

...your transistors voltage readings are all wrong...

...i "modified" the NPN layout you posted to what it should look like as a PNP layout...check to make sure you have done your layout correctly.

....what transistor are you using ?

AC

[Herec]

Hey Dragonfly,

The layout I posted I hadn't changed from its NPN state. I did the changes "in my mind".

I'm using an OC44

Anywho, I just dismantled the whole thing and decided not to build a new unit using new parts but just use your veroboard layout using the old parts.

Two questions:

1. On an axial capacitor, the end that has the silver "ball" is the positive end, correct?

2. How do I correctly measure the voltage readings of a transistor (or when you said my transistor readings were all wrong did you mean the values)

Thank you.

[Dragonfly]

Hey Dragonfly,

The layout I posted I hadn't changed from its NPN state. I did the changes "in my mind".

usually its best to "draw" out the changes till youve got quite a few builds under your belt...and even then its helpful...
btw...you switched the battery as well, correct ? (negative lead connects to 470k resistor and lug-1 of gain pot)

I'm using an OC44

good...

Anywho, I just dismantled the whole thing and decided not to build a new unit using new parts but just use your veroboard layout using the old parts.

just a note for future reference...often times you'll learn more about a circuit by "debugging" it than you could by just building it and having it "fire right up"...

Two questions:

1. On an axial capacitor, the end that has the silver "ball" is the positive end, correct?

2. How do I correctly measure the voltage readings of a transistor

set your MM at 20v ...on a pos ground circuit, touch rec lead to ground, black to the OC44's collector...you "should" optimally read about 7.2v, if everything is biased correctly (....incidentally, if you touch the red lead to the collector and black to ground, it'll read -7.2v)

(or when you said my transistor readings were all wrong did you mean the values)

yep...the values are off

Thank you.

no poroblem...good luck !

[Herec]

Hey Dragonfly,

I used your layout and it fired up first try. I'm pretty sure it was my layout, musta not switched something the right way.

Anywho I like the new layout better, its so small!

Thank you!

[petemoore]

I'm building an PNP Rangemaster

I used the NPN perfboard layout that I found but converted it to PNP (made the ground negative, turned around the capacitors)
  For use with a PNP transistor, the ground would be positive...battery positive would be ground.

[Dragonfly]

Hey Dragonfly,

I used your layout and it fired up first try. I'm pretty sure it was my layout, musta not switched something the right way.

Anywho I like the new layout better, its so small!

Thank you!

cool...glad you like it !

AC