wrote:
On Fri, 18 Aug 2006 19:54:00 +0200, "i3hev, mario held"
wrote:
Michael Black wrote:
However be wary of ICs like the MC1350 as the gain reduction occurs
the internal noise is bad. I've built several recievers using this
part and at ~10db gain reduction the noise jumps way up. I've gone
to cascode JFETs as the noise is more predictable and generally
lower. The device used does make a difference.
Allison
I have to disagree on the MC1350 and way back 30 years to its
predecessor, MC1590. The prototype HF receiver presently on
my workbench has a NF of 5.5 and that hardly rises more than
that with AGC current applied to the AGC pin.
BTW, that receiver, single-conversion with one IF at 21.4 MHz,
uses only MC1350s up to the detector, including the one mixer
stage. [ LO is a separate PLL board ]