On Nov 5, 7:43 am, Joe wrote:
On Nov 2, 9:01 pm, "numeric" wrote:

Looking for a transistor suggestion, for an RF receive pre-amplifier to
cover 10Hz to about 60Mhz. So far, I have found a pair of 2N5109B bipolar
transistors, which work ok in a grounded base push-pull design. These
transistors provide a gain of about 12db over an input voltage range of 1
microvolt or less to over 4 volts. These transistors were designed many
years ago; hopefully better transistors now exist which can provide superior
linearity and better isolation form input to output. In addition, a spice
model must be available.

Thanks.

He did ask for a RECEIVE pre-amp, to 60mHz
Not a power amp, and not 60GHz, and you don't need 4volts for a
receive preamp

How about and MPF102 JFET in Class A
Bias it at about 8mA, and you should get ~20db power gain

Because there are those of us who, for a "receive preamp", would very
much like to get IIP3 greater than +50dBm, and ideally up around
+60dBm. It may only need to handle 0dBm or +10dBm signals, but it
does need to have very low distortion. Not going to happen with an
MPF102, at least not without an exceptionally creative circuit around
it. I'm not quite sure why the OP wants a preamp in the first place,
since noise figure on HF is generally not that much of an issue. It
may be in part to get isolation between the mixer and the antenna so
he doesn't radiate the LO signal, but that can be done with tuned
circuits at least for narrowband radios. I have slightly different
reasons for wanting a modest gain very low distortion amplifier like
that. In any event, it would be a nice circuit to have in my "bag of
tricks."

Cheers,
Tom