2N1149 datasheet?

[LucifersTrip]

can't seem to find one...just wanted to be 100% certain of the ECB config before the solder starts to flow.

pic:
http://semiconductormuseum.com/MuseumStore/MuseumStore_2N1149_Index_files/image006.jpg

Is the stand-alone lead E or C?

thanx

[zombiwoof]

On the NTE Cross-Reference, it shows that the NTE 123AP is a direct sub, with an EBC pinout.  I would think the one lead that is off by itself might be the emitter.  If you don't know for sure, put it in your meter (if it has a transistor hfe checker) to check the pinout.

Al

[LucifersTrip]

On the NTE Cross-Reference, it shows that the NTE 123AP is a direct sub, with an EBC pinout.  I would think the one lead that is off by itself might be the emitter.  If you don't know for sure, put it in your meter (if it has a transistor hfe checker) to check the pinout.

Al

Yes, I checked the NTE cross site. I'm building the Jen Fuzz:
http://fuzzcentral.ssguitar.com/schematics/jenfuzzschem.gif

...which calls for a BC238B. The BC238B crosses to a NTE123AP. As you realized, the 2N1149 also crosses to  NTE123AP, which is why  I used it.

I actually found a Yahoo post:
http://ph.answers.yahoo.com/question/index?qid=20100116225242AARoHjf

"The base is the middle one. If it is a common transistor or thyristor then the base will still be the middle one and it is closest to the emitter leg if the markings on the device are rubbed or burned away. The collector will be the furthest away from the other two."

...and it seems he is correct. It is the collector that is by itself.

I actually did measure the 2N1149 on my hfe checker and I have to admit I am a total novice with transistors. It gave me a reading in both directions so I had no idea which one was correct.

I did throw the Jen Fuzz together last night. I got sound right away, but just a mild distortion instead of a fuzz. I'll work on the troubleshooting now.

thanx

[zombiwoof]

On the NTE Cross-Reference, it shows that the NTE 123AP is a direct sub, with an EBC pinout.  I would think the one lead that is off by itself might be the emitter.  If you don't know for sure, put it in your meter (if it has a transistor hfe checker) to check the pinout.

Al

Yes, I checked the NTE cross site. I'm building the Jen Fuzz:
http://fuzzcentral.ssguitar.com/schematics/jenfuzzschem.gif

...which calls for a BC238B. The BC238B crosses to a NTE123AP. As you realized, the 2N1149 also crosses to  NTE123AP, which is why  I used it.

I actually found a Yahoo post:
http://ph.answers.yahoo.com/question/index?qid=20100116225242AARoHjf

"The base is the middle one. If it is a common transistor or thyristor then the base will still be the middle one and it is closest to the emitter leg if the markings on the device are rubbed or burned away. The collector will be the furthest away from the other two."

...and it seems he is correct. It is the collector that is by itself.

I actually did measure the 2N1149 on my hfe checker and I have to admit I am a total novice with transistors. It gave me a reading in both directions so I had no idea which one was correct.

I did throw the Jen Fuzz together last night. I got sound right away, but just a mild distortion instead of a fuzz. I'll work on the troubleshooting now.

thanx

So the pinout was EBC, not ECB.  I was wrong about my guess that the standalone lead was the emitter, though!  I guess you got it sorted out, anyway.  Good luck.

I would think you just need to dial in the bias to get it to fuzz.  Try a trimpot in place of the bias resistor.

Al

[LucifersTrip]

On the NTE Cross-Reference, it shows that the NTE 123AP is a direct sub, with an EBC pinout.  I would think the one lead that is off by itself might be the emitter.  If you don't know for sure, put it in your meter (if it has a transistor hfe checker) to check the pinout.

Al

Yes, I checked the NTE cross site. I'm building the Jen Fuzz:
http://fuzzcentral.ssguitar.com/schematics/jenfuzzschem.gif

...which calls for a BC238B. The BC238B crosses to a NTE123AP. As you realized, the 2N1149 also crosses to  NTE123AP, which is why  I used it.

I actually found a Yahoo post:
http://ph.answers.yahoo.com/question/index?qid=20100116225242AARoHjf

"The base is the middle one. If it is a common transistor or thyristor then the base will still be the middle one and it is closest to the emitter leg if the markings on the device are rubbed or burned away. The collector will be the furthest away from the other two."

...and it seems he is correct. It is the collector that is by itself.

I actually did measure the 2N1149 on my hfe checker and I have to admit I am a total novice with transistors. It gave me a reading in both directions so I had no idea which one was correct.

I did throw the Jen Fuzz together last night. I got sound right away, but just a mild distortion instead of a fuzz. I'll work on the troubleshooting now.

thanx

So the pinout was EBC, not ECB.  I was wrong about my guess that the standalone lead was the emitter, though!  I guess you got it sorted out, anyway.  Good luck.

I would think you just need to dial in the bias to get it to fuzz.  Try a trimpot in place of the bias resistor.

Al

Yes, B center & C standalone. I'll definitely be screwing with the bias resistor today...along with all the others.

thanx again

[PRR]

> It gave me a reading in both directions so I had no idea which one was correct.

The primary difference between C and E in semi-modern transistors is that the E junction breaks-down at 7V and the C junction breaks-down at 40V.

In 9-Volt work, there may not be 7V either way. So it may work.

Before FETs, we used BJT transistors in "reverse connection" for very low-voltage signal choppers.

(And transistors as old as this sometimes have 25V E junction break-down....)

Secondarily, the gain is higher one way than the other. The E junction is doped for gain (sacrificing break-down) and the C junction is doped for break-down (sacrificing gain).

I _think_ the way which shows the higher hFE is "probably" the intended pin-out. Though on a device this old there may be other reasons to go one way or the other.

[LucifersTrip]

Thanx for the info...that shouls help out in the future.