On Sat, 19 Jun 2004 22:18:46 -0400, Ken Scharf
wrote:

I saw a web page somewheres showing that you can simulate a dual gate
mosfet with two jfets in series cascade. J310's work well in this
circuit and they are cheap.

Though not if you buy them from MkV in the UK where they want seven
quid! What's that...$11 for a lousy common JFET. Happily they're
readily available elsewhere for a fraction of that ridiculous price.
Yeah, the cascade solution's good if space permits.

--

"What is now proved was once only imagin'd." - William Blake, 1793.

Bill Hennessy wrote in message om...
Does anyone know where I can get a double gate fet like the old 40673?
I know Ocean State has it but it's kind of high $8.50, I know their are
others like the 3N201 and BF900. But can't seem to find them anyplace.

Bill, N5NOB

What sort of project did you have in mind? There
is a reason they don't make 40673s any more, and I
am always slightly suspicious when somebody is
looking specifically for them. At the height of
their popularity, ham projects used 40673 for all
sorts of things. Now, about the only thing people
still do with them is low-noise RF amplifiers
(e.g. BF991).

My supply of BF961/981s came from Cricklewood in London
and Les Cyclades in Paris. Barend Hendriksen have them
too.

Laura Halliday VE7LDH "Que les nuages soient notre
Grid: CN89mg pied a terre..."
ICBM: 49 16.05 N 122 56.92 W - Hospital/Shafte

Laura Halliday wrote:
Bill Hennessy wrote in message om...

Does anyone know where I can get a double gate fet like the old 40673?
I know Ocean State has it but it's kind of high $8.50, I know their are
others like the 3N201 and BF900. But can't seem to find them anyplace.

Bill, N5NOB


What sort of project did you have in mind? There
is a reason they don't make 40673s any more, and I
am always slightly suspicious when somebody is
looking specifically for them. At the height of
their popularity, ham projects used 40673 for all
sorts of things. Now, about the only thing people
still do with them is low-noise RF amplifiers
(e.g. BF991).

My supply of BF961/981s came from Cricklewood in London
and Les Cyclades in Paris. Barend Hendriksen have them
too.

Laura Halliday VE7LDH "Que les nuages soient notre
Grid: CN89mg pied a terre..."
ICBM: 49 16.05 N 122 56.92 W - Hospital/Shafte

A regenerative receiver by useing one of the gates in the normal way.
And the other is used with a pot to controal the voltage and will affect
the regeneration. The FET is acting like a screen-grid tube or
replaceing the tube.

Send me a SASE and I'll send you a pinch of BR998 dual gate mosfets (better
than 40673, but small surface mount package,, but will still solder down to
0.1 inch spaced pads if a little care is taken.

Bob, KE6F

Bob Miller, KE6F
9655 Appalachian Dr.
Sacramento, CA 95827

73
Bob