"bcdlr" ) writes:
All good answers. The main reason I was not going to build a Micro R2
was not the building but the single band.
I wanted something multiple band and as to frequency readout I was
thinking of adding a digital dial.

But this goes back to the previous thread.

It's far better to build a single band receiver well, and get it
working, than to deal with the issues of multiple bands.

But, that receiver will work all over the place, with some changing
of frequency sensitive circuitry. One of those R2 receivers is
even set up for using modules to change bands.

One of the points of building a receiver that tuned a fixed range,
and then putting converters ahead of it, was that you could build
the main receiver, and use it immediately, and then deal with adding
the other bands.

I've often felt it makes lots of sense to make a good receiver, minus
the frequency selective elements, and then put it into a good box.
Put the "variable oscillator" in a separate box, so you can have a simple
single band VFO to begin with, or even a crystal oscillator for a fixed
frequency, and get the receiver going easily. Then you can work on
the fancier wide range synthesizer, or go through various iterations.
The basic receiver is always available, and so is the fallback variable
oscillator, which is not the case if you need to put the receiver on
the workbench to make some modification.

Now that broadband techniques have come to amateur radio, your "black
box" receiver can keep the frequency selective elements outside the
box. You can play with plug-ins for the desired bands, or something
that switches the LC circuits. Or both, migrating from the simple
to the complicated. You might find that on some bands that are less
important to you, you can get by with a simpler front end filter,
but other bands you want something fancier. If you build a receiver
all in one box, and the ultimate is the end goal, then you don't have
the chance of having the receiver relatively early, and you don't learn
from the experimenting. Plus, your ultimate standards have to be
there across the bands, rather than applied selectiviely.

Ray Moore wrote an artilce in Ham Raido magainze about 1973 or '74 about
receiver design, and showed off what was to him his "ultimate receiver".
But it was a broadcast band receiver, which few of the readership would
be interested in. He was merely using it as an example. His point was
that it's easier to build a really good receiver for a dedicated task
than to build a general purpose receiver that does everything well. He
mentioned that commercial receivers were often a series of tradeoffs because
they needed to provide something to a wide range of buyers, yet then
people are often paying extra for features they will never use.

Starting with a "black box" provides a lot more flexibility than when
putting the frequency selective elements in the box.

It doesn't even have to be the R2. Get a good passive mixer, a decent
SSB-bandwidth 9MHz crystal filter (or build one), and then build up a good
basic receiver that doesn't work without added circuitry. ANd use
that as the "black box".

Michael VE2BVW