Hi
Where can I buy BF422 BF423?
I am trying to buy BF422 but Mouser just stopped selling them. They used to be 200 for £20. However they are no longer available at Mouser and they do not plan to restock. BF423 are also getting scarce.
The specs for BF422/423 are;
Vdc 250
Ima 50
mW 600/800
MHz 60
gain 50
Cpf 2.8/1.6
BF421/423 are the same except 300Vdc however these have not been around for some time.
Don
Where can I buy BF422 BF423?
I am trying to buy BF422 but Mouser just stopped selling them. They used to be 200 for £20. However they are no longer available at Mouser and they do not plan to restock. BF423 are also getting scarce.
The specs for BF422/423 are;
Vdc 250
Ima 50
mW 600/800
MHz 60
gain 50
Cpf 2.8/1.6
BF421/423 are the same except 300Vdc however these have not been around for some time.
Don
Hi
Thanks for the replies
Mjselan Thanks; these look nice parts, however I am hoping to find some semiconductors with a lower capacitance. In the BF422 and BF423 the capacitance is 1.6 / 2.6 pf as against 7pf in most of the possible replacements I have seen todate.
Katie and dad Yes both of these sources do sell the parts. However the price at other companies has always been around £0.07 per part as against £1.25 and £0.25 at the companies you mention. Those sounces are OK if you only want 1 or 2 for replacements but the prices are not realistic for orders of more than 1 or 2.
Don
Thanks for the replies
Mjselan Thanks; these look nice parts, however I am hoping to find some semiconductors with a lower capacitance. In the BF422 and BF423 the capacitance is 1.6 / 2.6 pf as against 7pf in most of the possible replacements I have seen todate.
Katie and dad Yes both of these sources do sell the parts. However the price at other companies has always been around £0.07 per part as against £1.25 and £0.25 at the companies you mention. Those sounces are OK if you only want 1 or 2 for replacements but the prices are not realistic for orders of more than 1 or 2.
Don
Do you really need the 250V breakdown?
The KSA916/KSC2316 may be suitable substitutes.
Be careful when comparing capacitance specs from Data Sheets. The values vary over a WIDE range depending on test conditions (i.e., the amount of reverse bias on the PN junction). A manufacturer who publishes a spec based on a modest reverse bias of 5 or 10 volts may show a worse value than a manufacturer who measures with 50 or 100 volts - even though the "worse" part is actually faster!
Dale
The KSA916/KSC2316 may be suitable substitutes.
Be careful when comparing capacitance specs from Data Sheets. The values vary over a WIDE range depending on test conditions (i.e., the amount of reverse bias on the PN junction). A manufacturer who publishes a spec based on a modest reverse bias of 5 or 10 volts may show a worse value than a manufacturer who measures with 50 or 100 volts - even though the "worse" part is actually faster!
Dale
AFAIK, BF420..423 are current production parts from NXP China and widely available. The Toshiba counterparts are a bit scarcer. You can look for BF821 if SOT23 works for you.
Thanks for thr replies. I did manage to find some BF422 from Toshiba but I believe I may have got the last ones around.
Ketje
Thanks for your suggestions. I tried the company you suggested. He had just sold out the week before and his friends had also sold out the week before.
D Chisholm
You may well be correct that the capacitance figures are not what they seem with some transistors. However I always try to buy transistors with the most linear transfer curves and lowest capacitance. The audio equipment I have built seems better when I stick to that position - and some makers do claim that their parts were designed to have low capacitance.
linuxguru
Thanks for your help although I do have all the parts I need now.
Thanks for thr help
Don
Ketje
Thanks for your suggestions. I tried the company you suggested. He had just sold out the week before and his friends had also sold out the week before.
D Chisholm
You may well be correct that the capacitance figures are not what they seem with some transistors. However I always try to buy transistors with the most linear transfer curves and lowest capacitance. The audio equipment I have built seems better when I stick to that position - and some makers do claim that their parts were designed to have low capacitance.
linuxguru
Thanks for your help although I do have all the parts I need now.
Thanks for thr help
Don
- Status
- Not open for further replies.