re nikko alpha parts
Hi Tom
Try main electronics in Vancouver. They have some of the devices
you seek. Didnt see the 2sc2088 though. Try conatacting them
maybe they can get them.
http://www.mainelectronics.com
Good Luck
Hi Tom
Try main electronics in Vancouver. They have some of the devices
you seek. Didnt see the 2sc2088 though. Try conatacting them
maybe they can get them.
http://www.mainelectronics.com
Good Luck
The 968 and 2238 have a bandwidth of over 100 MHz, remarkable i think for a 25 watt device.
And with very low capacity !
Hfe for these is between 200 and 700.
An 2SA1667 only goes to 15-20 MHz, i think.
Capacity is twice of the one for the 968.
Hfe no higher than 200.
The 968 and 2238 were produced in 160/180/200 types.
Overhere we still have them, thank goodness.
And price is half of that for the 1667/4381.
(i bought a doodoo load for matching at CAD$ 0.60 when Elektor started using them in the high 80s)
Can you still have the 2SA1859A/2SC4883A overthere ?
Those are a decent substitute for the 968/2238, imo.
(180V, 2A, 120 MHz, Hfe~240, 20watts )
btw:
if anyone has a picture of the insides of the Nikko, i am game.
I wished i had known about it at the time.
For the ones who are not bored out of their skull from my ML talks: Levinson used the 2SD555 and 2SB600 in one of their amps.
And with very low capacity !
Hfe for these is between 200 and 700.
An 2SA1667 only goes to 15-20 MHz, i think.
Capacity is twice of the one for the 968.
Hfe no higher than 200.
The 968 and 2238 were produced in 160/180/200 types.
Overhere we still have them, thank goodness.
And price is half of that for the 1667/4381.
(i bought a doodoo load for matching at CAD$ 0.60 when Elektor started using them in the high 80s)
Can you still have the 2SA1859A/2SC4883A overthere ?
Those are a decent substitute for the 968/2238, imo.
(180V, 2A, 120 MHz, Hfe~240, 20watts )
btw:
if anyone has a picture of the insides of the Nikko, i am game.
I wished i had known about it at the time.
For the ones who are not bored out of their skull from my ML talks: Levinson used the 2SD555 and 2SB600 in one of their amps.
Hi SR71,
You have to watch the suffix on those parts. 2SC2238, 2238A, 2238B. The collector emitter breakdown goes up towards "B". Watch you are looking at collector emitter, not collector base voltages. 2CS2336, 2SA1006 are 180V 1.5A. The "B" versions get us up to 250V. They should still be available as well.
-Chris
You have to watch the suffix on those parts. 2SC2238, 2238A, 2238B. The collector emitter breakdown goes up towards "B". Watch you are looking at collector emitter, not collector base voltages. 2CS2336, 2SA1006 are 180V 1.5A. The "B" versions get us up to 250V. They should still be available as well.
-Chris
Lights up the room.... Now what?
Reply to email for others to keep up on thread. Boom - oops!
Hi Tom,
These things confuse us all. We know better but do "it" anyway. Now we know why we knew better.
Power off. Discharge caps. Meter on diode test. Test all transistors for two diode drops E-B and C-B. Shorts normally rule out a transistor from being good. Take pictures of stuff before taking apart. Make notes. Retest all low value resistors. Report on what's dead and what's not. Drink coffee & smile.
-Chris
Hi Tom,
These things confuse us all. We know better but do "it" anyway. Now we know why we knew better.
Power off. Discharge caps. Meter on diode test. Test all transistors for two diode drops E-B and C-B. Shorts normally rule out a transistor from being good. Take pictures of stuff before taking apart. Make notes. Retest all low value resistors. Report on what's dead and what's not. Drink coffee & smile.
-Chris
what could have happened?
I'm sort of in the dark is to the reason for my short across the resistor. I obviously don't want that fiasco to occur again. Fundamental question: When measuring bias, I am measuring current, correct? So... If I set my DMM correctly, for mA, black lead in common, red in mA, and I measured across a resistor, why would it spark and create a short. I could kick myself now, but I was trying to establish a baseline for comparison to the faulty right channel. Of course, now I've increased my fun factor a few notches, and have two problems to deal with. My hat is off and much respect to all you pros out there!!!
Tom
I'm sort of in the dark is to the reason for my short across the resistor. I obviously don't want that fiasco to occur again. Fundamental question: When measuring bias, I am measuring current, correct? So... If I set my DMM correctly, for mA, black lead in common, red in mA, and I measured across a resistor, why would it spark and create a short. I could kick myself now, but I was trying to establish a baseline for comparison to the faulty right channel. Of course, now I've increased my fun factor a few notches, and have two problems to deal with. My hat is off and much respect to all you pros out there!!!
Tom
A brief synopsis of where things are
Before I start my re-checking, here's a brief synopsis of the state of Nikko Alpha II. Apply power on; relay does not trip, remains in protect. Prior to the right channel fiasco, right channel functional with meter lamp lit. Now right meter lamp is also out. Lamps pass continuity check. Thought I might have fried them too! There is a change in status of the right channel (the original problem channel. I reported in a previos post that upon power up, the "test light bulb" stays brightly lit. Now, upon power up, it illuminates brightly, then dims to a dull glow. But then I sensed an odor from the power amp board, and immediately cut power (I only did this once.)
Started re-checking the components as instructed, but I can't seem to locate anything suspicious yet. Can I effectively check these components while they are soldered to the board? For example, the meter was reading a short across a transistor, only to have it check out okay when removed from the board. But then with other T's, they seem to check out okay in place? Huh?
Tom
Before I start my re-checking, here's a brief synopsis of the state of Nikko Alpha II. Apply power on; relay does not trip, remains in protect. Prior to the right channel fiasco, right channel functional with meter lamp lit. Now right meter lamp is also out. Lamps pass continuity check. Thought I might have fried them too! There is a change in status of the right channel (the original problem channel. I reported in a previos post that upon power up, the "test light bulb" stays brightly lit. Now, upon power up, it illuminates brightly, then dims to a dull glow. But then I sensed an odor from the power amp board, and immediately cut power (I only did this once.)
Started re-checking the components as instructed, but I can't seem to locate anything suspicious yet. Can I effectively check these components while they are soldered to the board? For example, the meter was reading a short across a transistor, only to have it check out okay when removed from the board. But then with other T's, they seem to check out okay in place? Huh?
Tom
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