[HBR] WARC bands?

[Walt Hutchens]

Ian said:

> I  think that one problem with the crystal-controlled converter
> in front of a tunable IF is that you may decide to adopt that
> architecture instead of the HBR! - worked pretty well for Collins,
> after all.

It worked very well for Collins but no receiver using this
architecture could be called 'simple' or 'easily duplicated by a ham
with modest skills.'

The Collins receivers mostly used two or three two IFs, at least one
of them tunable. Often one IF was either shifted or omitted on some
bands. Multiple conversions (and sometimes a varying number of
conversions) make these sets very difficult to design for a strong
signal environment like the ham bands. Collins did it, all right, but
they went out of business because they could never recover the cost of
the engineering.

Never say 'never': There may be situations where a crystal controlled
converter ahead of an HBR is the way to go -- perhaps you're not the
builder of the HBR and you can't do that sort of coil winding: The
coils for a converter ARE simpler, since they usually aren't expected
to deliver any selectivity. And specific coil data will be included
with any description of such a converter.

Converter design is a thing unto itself and if one wants to learn
about it, this might be a good way to go. Equal performance (to just
winding the WARC coils) will be tricky but that could be part of the
fun.

Walt
KJ4KV