ID a FET or BJT

I was writing for Popular Electronics in 1996, but it isn't mine. I'm guessing the schematic was mis-transcribed. If sufficiently motivated I may go and look and see if I can find it. Can the person who posted the circuit tell us which issue and page he got it from?

"Watson A.Name - "Watt Sun, the Dark Remover"" wrote in message news: snipped-for-privacy@corp.supernews.com...

It's the sort of circuit where you'd see the 2N918. Oddly, it crosses at the ECG site to the ECG108, basically the same as one the bit mentions (though I didn't do a direct comparison).

I don't think the exact type is going to matter. It's a cheap FM preamp, and it's not likely to work that well anyway. It's bound to overload in an urban area, and as you say oscillate. But it's the configuration that will oscillate, not the particular bipolar transistor. SOmething with reasonable gain, and a high bandwidth is what's needed; pull one off an existing FM tuner, or an old TV tuner. Or for that matter, copy the the full circuit from the FM tuner.

A few years back I came across "FM preamplifiers" in a dollar store, selling for an actual dollar if I recall. They were in the window, so I went in and bought one. Turned out to use an actual mosfet, so I went back and bought the three or four that remained. The circuit was very simple, not what you'd expect to find in decent equipment. I never even tried one out.

Most FM tuners are too sensitive, and an amplifier won't do anything even if it does work.

Michael

self

metal

datasheets

Well, I found a source for those elusive MFE201s. Ebay.

Howsomever, they're worthless for this circuit. They are dual gate MOSFETs, which are nowheres near what the circuit needs. I think antoon is just making another huge boo-boo, as he has done in many other schematics.