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Needing transistor equivalents

bmallett

bmallett

New Member
I am a bit green to fully understanding the solid state transistors. I was able to round up the actual part numbers for the following transistors, but at $70 shipped, the 6 I needed were more than the unit's worth IMO.

Someone mentioned getting the newer equivalent transistors, but when I tried to look them up, it honestly went over my head. I'm hoping if I post the originals and their specs, one of the more educated members can help me out. :)

Thanks guys!


2SA640 Transistor Datasheet:
Type Designator: 2SA640
Material of transistor: Si
Polarity: PNP
Maximum collector power dissipation (Pc), W: 0.25
Maximum collector-base voltage |Ucb|, V: 50
Maximum collector-emitter voltage |Uce|, V: 45
Maximum emitter-base voltage |Ueb|, V: 5
Maximum collector current |Ic max|, A: 0.03
Maksimalna temperatura (Tj), °C: 125
Transition frequency (ft), MHz: 50
Collector capacitance (Cc), pF: 15
Forward current transfer ratio (hFE), min: 100
Noise Figure, dB: -
Package of 2SA640 transistor: TO92


MPSU06 Transistor Datasheet:
Type Designator: MPSU06
Material of transistor: Si
Polarity: NPN
Maximum collector power dissipation (Pc), W: 10
Maximum collector-base voltage |Ucb|, V: 80
Maximum collector-emitter voltage |Uce|, V: 80
Maximum emitter-base voltage |Ueb|, V: 4
Maximum collector current |Ic max|, A: 2
Maksimalna temperatura (Tj), °C: 150
Transition frequency (ft), MHz: 50
Collector capacitance (Cc), pF: 12
Forward current transfer ratio (hFE), min: 80
Noise Figure, dB: -
Package of MPSU06 transistor: X17


2SC485 (B1) Transistor Datasheet:
Type Designator: 2SC485B
Material of transistor: Si
Polarity: NPN
Maximum collector power dissipation (Pc), W: 0.8
Maximum collector-base voltage |Ucb|, V: 120
Maximum collector-emitter voltage |Uce|, V: 80
Maximum emitter-base voltage |Ueb|, V: 5
Maximum collector current |Ic max|, A: 1.5
Maksimalna temperatura (Tj), °C: 150
Transition frequency (ft), MHz: 10
Collector capacitance (Cc), pF:
Forward current transfer ratio (hFE), min: 100
Noise Figure, dB: -
Package of 2SC485B transistor: TO39


2SA485 (B1) Transistor Datasheet:
Type Designator: 2SA485B
Material of transistor: Si
Polarity: PNP
Maximum collector power dissipation (Pc), W: 0.8
Maximum collector-base voltage |Ucb|, V: 80
Maximum collector-emitter voltage |Uce|, V: 80
Maximum emitter-base voltage |Ueb|, V: 5
Maximum collector current |Ic max|, A: 1.5
Maksimalna temperatura (Tj), °C: 150
Transition frequency (ft), MHz: 10
Collector capacitance (Cc), pF:
Forward current transfer ratio (hFE), min: 100
Noise Figure, dB: -
Package of 2SA485B transistor: TO39
 
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So I am trying to get this figured out to keep moving forward on this repair. So far, I think the first two would work. I just don't know about the 485 pair.

Looking for a good sub on the 2SA485(B1) and 2SC485(B1)

2SA640 with 512-KSA992FBU
MPSU06 with MJE243G(NPN)
2SC485(B1) with ???
2SA485(B1) with ???
 
The 2SC458 are known to fail and be noisy. From my reading on here, many techs on here are using KSC1845 as a suitable replacement.
 
dherrick said:
The 2SC458 are known to fail and be noisy. From my reading on here, many techs on here are using KSC1845 as a suitable replacement.
Click to expand...

The ones that are specd are 2SC485 not 2SC458. I didn't see anything referencing them as equivalent, but I am not completely knowledgeable on these either.
 
Hyperion said:
Just search AK for the transistor type numbers you want to substitute, seldom come up empty.

There is also a thread dedicated to this exact topic, somewhere...

Here
http://audiokarma.org/forums/showthread.php?t=583009
Click to expand...

I ran across that post, but I didn't see any of the ones I had on there.

I've also looked on various sites to find equivalent ones, but the values vary so much and they caution to use what's suitable for the application. Being I am unsure of transistors, I am at a loss on deciding the right ones. :(
 
elnaldo said:
Do you need that TO39 case?
Click to expand...

Honestly, I'm not sure. I am trying to replace the transistors that are in place on the board now. The specs call for one thing, but the existing ones are another. It doesn't appear that anyone has been in here before. If so, they are clean with their work.

The specs call for 2SA640, MPSU06, 2SC485(B1), and 2SA485(B1).
The existing ones are A561, C983, C1382-0, and A682-Y

Here are pictures of each one in there now. Keep in mind, I don't know if these are correct though. Their numbers read differently that the ones in the original specs.
 

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Ray Gianelli said:
I've had good luck with this site:

http://www.alltransistors.com/

You have to select the transistor after the search (it may come up with the same number with different suffixes, for example) then click the hyperlink for equivalents.

HTH, Ray
Click to expand...

Thanks Ray. That's where I've been getting the info I have thus far. ;)

The only two that really seem to be problematic with any of my electronic buddies or groups seem to be the last pair. :(
 
If the unit is working, you could stay with what's in the unit now. Add a "2S" to the numbers you wrote.

Check specs of the transistors in the unit, just in case. Usually, you match (or exceed) Vbe, Ic, and ft (MHz).

Depending of the application , ft is not important.

BTW, what's wrong with the actual transistors?
 
elnaldo said:
If the unit is working, you could stay with what's in the unit now. Add a "2S" to the numbers you wrote.

Check specs of the transistors in the unit, just in case. Usually, you match (or exceed) Vbe, Ic, and ft (MHz).

Depending of the application , ft is not important.

BTW, what's wrong with the actual transistors?
Click to expand...

They are out of spec on the output. The fm output is weak.
 
I got this wrong, my response was to someting else. Delete please.
 
Last edited:
"They are out of spec on the output. The fm output is weak. "

I is not transistors. DO NOT just change transistors in a tuner, EVER. The worst thing you can do.

If you have low FM utput, and I would assume the thing will not kick into stereo, the place to look is the limiter stage that feeds the discriminator or ratio detector coil, and of course the coil itself as they do go, as well as some of the associated reactive components.

And WHY don't peoplle post the make and model of what they're trying to work on ? Stupfickingitidity ? You think that part only has one purpose and that all manufacturers are made to use it the same way, like by law or something ?

Make and model number. Without that you will not get much REAL help.

You THINK you know. Like those people who put a full race cam in their car and do not even think about the torque convertor or the rear end. A little knowledge is enough for them to extract your money. Like peoplke who run the codes on their car when it doesn't run eright and change $500 worth of sensors n **** and then run into someone who knows WTF they're doing and it is fixed for fifty bucks, total, including beer ! Knowledge is power, knoledge is ALOT of power. We ain't fraid of the governemnt even, becausae they do not have the knowledgre. Yup they have a tape of the phone conversation between you and your Aunt May, but they can't change a tire, or an O2 sensor, or a leaky pipe. They are where we send out useless people.

Your unit needs a part that costs eleven cents. It will cost you maybe fifty bucks to find out which one. This is why technicians make money.

If you change all those transistors, I wkll not even consider evenb looking at the thing for any amount of money, and don't try to fool me I can tell. I can tell almost for sure ho many times a unit has been worked on and to some extent WHEN. you throw that alignment off that way and that is a hundred times harder to correct in some units.

Now how about instead of thinking you can dogfight in an F-16 (or F-35 LOLOLOLOL) we get started on getting that Cessna off the ground ?

Make, model and symptom.

We go from there.

If you are hell bent on wrecking it, just use 2N2222s in all the spots and don't worry about polarity or basing, The end result will be about the same. If you want to really FIX it then you have to TROUBLESHOOT it.
 
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I think a BC560 should work. Pinout is different, check before installing. A KSA992 could work too.

Please check and compare the datasheets and application in your circuit.
 
Hi Elnaldo ✌
You mean BC560 to replace the 2SD811s ? What about the BD317 that I have replaced ? Are they compatible ? Pins meaning the 2 pins of the transistor ? They are Emitter and Base and the metal case is the Collector I believe. When I checked using my tester it shows the E, B and C. And I fit it into the slot respectively. Furthermore these large metallic transistors fit one way only. If it's wrongly fitted, the securing screws can't go in.
KSA992 is another option ?
I'm not a professional technical guy to go I to data sheets . What I do is since the original part numbers are not available, I ask the shop guy to check in their book for alternative part numbers. Can confirm in Google ✌
Can 2SA640 transistor be replaced with A1137? 2SA640 is not available either. So are the rest
 
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