I can find at the local dealer a BF471 and BF472 video application transistors. Those are, if Philips production, quite good transistors with low Cob of 1.8pF, to be used instead 2SA1380/81 and 2SC 3502/03.
Does anyone has experience with CDIL production of those BF transistor, are thy any good, as those are possible to be found local here?
Does anyone has experience with CDIL production of those BF transistor, are thy any good, as those are possible to be found local here?
I use BF469 and BF470, but I do not trust my model for those transistor. The datasheet do not have many information.
BF469 -> VAF=25.51 ?
BF470 -> VAF=465.9 ?
Do have better models?
No, I don't have better models. I measured the Hfe for Philips 471/472 and it was between 120 and 140. It is not question of the models but haw they work in real amp and if CDIL are good enough.
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Just need to get the heat to a piece of copper, then to a sink.
Or glue a sink directly on top of the package.
At least you know it is NXP and not some unknown Fab.
Patrick
Or glue a sink directly on top of the package.
At least you know it is NXP and not some unknown Fab.
Patrick
I used these devices on my Ovation 250 power. They are very good devices with low Cob. However, the spice models are terrible.
They were discontinued about 10 years ago - so make sures you are getting NOS and they they are not fakes.
They were discontinued about 10 years ago - so make sures you are getting NOS and they they are not fakes.
He asked about CDIL company.
Look here.BF471 - Continental Device India Ltd
It seems like CDIL isn't the manufacturer of those transistors.
Look here.BF471 - Continental Device India Ltd
It seems like CDIL isn't the manufacturer of those transistors.
I believe that all models of the BF series (BF42x, BF47x, BF62x BF87x are based on one and the very same crystal, just different housing, just compare the datasheets from the same mfg. Hell, even the spice models are almost identical. They are all very, very good transistors...just don't expect to deliver much current!
It says CDIL on the package and datasheet is here: BF471 Datasheet(PDF) - Continental Device India Limited
It could be used as a VAS transistors or BF42x as replacement for 2SA970/2SC2240.
All variants could be use as vas transistors (I have used the TO-202 as vas and pass devices in HV regulators for tube stuff). For input duty, if you are Phillips buff, I would recommend even more rare diamonds...the one and only BFV420/421😉...Also, if you want to replace some relatively low Vce japanese pinout transistors with Philips BC550/560...don't, you have Philips JC55x/JC56x for that.
I am not Philips buff, just want good transistor but not unobtainable types. Where I can buy JC55x/56x (NXP?) transistors and BFV420/421 those look really good?
Today, devices like the ones above comes from only one place...China, sorry!
China is not problem, fakes are the problem. Do you know reliable source?
I buy all obsolete devices via taobao...so you have to be very patient and very careful. If you are interested, I could recommend my taobao agent (off line)...not a single hick-up yet and very good english for a change.
e.g. JC547B JC557C JC547AÈý¼«¹Ü ½ø¿ÚPHIÆ·ÅÆ TO-92 ±¾Æ·10¸öÆðÂô-ÌÔ±¦Íø
e.g. JC547B JC557C JC547AÈý¼«¹Ü ½ø¿ÚPHIÆ·ÅÆ TO-92 ±¾Æ·10¸öÆðÂô-ÌÔ±¦Íø
Alternatives
Hi, Don't know if you went to the NXP device, but Fairchild do KSA1381 and KSC3503. These are supposed to be 2SA & 2SC look-alikes. Both available through Farnell in Europe.
Hi, Don't know if you went to the NXP device, but Fairchild do KSA1381 and KSC3503. These are supposed to be 2SA & 2SC look-alikes. Both available through Farnell in Europe.
using the Fairchild Ib=50uA curve I get Vaf for the
ksa1381 as ~841Vaf, & Cob ~4.2pF @ -10Vce
ksc3503 as ~1106Vaf, & Cob ~3.2pF @ 10Vce
Farnell are charging 30p+vat for 30off ksa1381e & 31p+vat for 25off ksc3503d
Farnell offers KSC3503 in D grade only, and KSA1381 in E grade only, so not easy to match and quite low hfe.
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