From: "Brian Howie"
Subject: Re: BFY91 - What on earth is this?
Date: Wed, 8 Jan 2003 13:24:14 -0000
Organization: Computer Sciences Corporation
NNTP-Posting-Date: Wed, 8 Jan 2003 13:24:15 +0000 (UTC)
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X-Original-Trace: 8 Jan 2003 13:23:15 GMT, esk2649.ct.edinbr.gecm.com
"- = krusty = -" <email@example.com> wrote in message
> Hi all,
> I have a circuit for a masthead preamp that uses a BFY91 tranny, about
> I can find very little information. I have found that the following are
> BFY92 or 2N2639...2N2644, 2N2913...2N2920.
> These are dual transistors, whatever that means and they certainly have
> legs than the normal 3. I think they have six, which would imply that it
> 2 transistors in one package!?
> OK, but, the diagram I have shows only 3 pins being used. Can I then use
> some other transistor? If so, what should I use?
> I have attached the circuit diagram.
> BTW - I plan to use this to boost signal reception to my airband receiver.
> (good idea or not?)
It might be a BFY90 -a four legged friend. The case pin won't be shown on
the circuit. It's a lowish noise (5db/500MHz) VHF Transistor with an ft of
1GHz. It's a very old device. a BFR91 might be better.