I think the main issue with the contemporary transceivers is covering DC to
daylight and trying to make the thing work. A single band design seems to
be a lot easier to make bulletproof.

Modern QRP design has advanced a lot since the DeMaw days, even over the
venerable 75s4. Take a look at designs by K8IQY or AD6A or N7VE and you
will find receivers that will be head and shoulders beyond anything that
W1FB ever dreamed of.

The front end overload issues on simple receivers seems to be largely
related to the use of the 602/612 mixer. The passive mixer, or Tayloe
mixer, designs seem to fare much better. The Elecraft K1 is the exception
that proves the rule; I suspect careful gain management may have something
to do with that.

KK7B has also written a LOT on receiver design, and his designs have a good
rep, but I've never used them so I can't comment from experience.

Doug's designs are fun, and sort of nostalgic, but if you are looking for
21st century performance, it isn't the place to look.

...

wrote in message
ups.com...
I don't much like the receivers I've used in contemporary tranceivers
-- the general coverage synthisized open front end ones. (I hasten to
add I haven't used any of the $4000 rigs; can't afford them). But the
ones I have used seem plagued with near-signal desensitization, front
end overload, etc., and I suppose all that comes from putting the
selectivity so far downstream.

I'm almost tempted to get an old 75s4 and shut up, but I really don't
need another room heater, so, instead, I'm thinking of building my own
receiver along the lines laid down by the late Doug DeMaw in his _QRP
Notebook_. Single conversion 160m superhet with Collins mechanical
filters in the IF and a series of down-converters for the other bands.
Anybody got any experience with the DeMaw Design?

Jim, K5YUT