[Elecraft] H mode mixer

[Giancarlo Moda]

Hi Julius and Geoff and all.....

Thanks again for your notes. I hope to be clear on all
of them. 

I will reply to both Geoff and Julius notes and these
will match Geoff comments/questions (I hope).

--- Geoffrey Mackenzie-Kennedy
<gmk at gm4esd.fsworld.co.uk> wrote:

> Hi Julius,
> 
> It might have something to do with Intellectual
> Title, but not being well 
> versed in such matters I could well be wrong. I have
> read very recently that 
> the H-Mode is being used in a new receiver for
> military use, and I know that 
> Rhode & Schwarz use a very similar mixer in one of
> their "Professional" 
> receivers designed during the mid or late 1990s - I
> would have to look up 
> the model. Perhaps the differences in the R&S mixer
> are sufficient to 
> prevent legal problems. 

NO, that is not an H-Mode Mixer althought it was a
simple switched single balanced demodulator using
CD4066.

> I have asked myself the same
> question as yours 
> because the original H-Mode design appeared at least
> 15 years ago and has 
> been "maturing" ever since, and without any doubt is
> a high class performer.
> 
> In the European amateur press the H-Mode has
> received good coverage which 
> includes the publication of rceiver designs in which
> the mixer is used. The 
> ARRL Hanbook 2001 includes a description of the
> "Triad" receiver, a relative 
> of the receiver in the CDG2000, the latter was
> offered as a kit if memory 
> serves me right.

The H-Mode Mixer (3 transformers) using both SD5000
and FST3125, referred to the TRIAD (W7AAZ, W4ZCB and
G3SBI) is reported in the ARRL Book EMRF Design.

> 
> 73,
> Geoff
> GM4ESD
> 
> 
> Julius N2WN wrote:
> 
> 
> > Geoff & Gian,
> >
> > To play devil's advocate (I'm decent in this
> role), if
> > the H-mode mixers is as simple and as effective as
> you
> > both suggest. Why hasn't it been more widely
> adopted?

Good to know you are an "advocate" ... I may have to
use your services if some friends may blow-up their
equipments when volunteering on Mixers mods...hi

The answer maybe simple... see below

> > For the most part, I've seen a couple mixers
> boards
> > and mostly references to homebrew building, but
> > nothing in the way of kits or commercially offered
> > radios.
> >
> > Considering how difficult the 40M situation is in
> > Europe, and how large the ham population is,
> certainly
> > one would think that someone would have championed
> the
> > technology by now...
> >
> > Any thoughts on this?

Intellectual rights on the H-Mode Mixer belong to
Colin Horrabin, G3SBI, and manufacturers do not like
to pay some extra $$$$ or ££££ or €€€€€ (Euro) ... or
maybe they try not to use someone else "brain
products" ... I guess ... hi.

The H-Mode Mixer has been used in two important
European Designs, as already mentioned, CDG2000 (G3SBI
part of the team) and Pic-A-Star or STAR by G3XJP. In
both designs you will see the "presence" of Bill,
W7AAZ and Harold, W4ZCB, particularly in the STAR.
Many European homebrewer designs have included the
H-Mode mixer in both 3T and 2T configurations. A
couple of projects are also been undertaken in JA-land
(see JA9TTT webpage).
Also several mods to commercial equipment have been
undertaken mainly in Europe and a couple in W-land.
When I published the I7SWX 2T H-Moder Mixer
configuration, LZ1OV produced the PCBs and if I do
recall over 200 pieces were sold all over Europe and
some in W-land and JA.

Why the H-Mode Mixer is not so well known in W-Land?
this is a question people may ask --- maybe is due to
the fact that QST is OK to publish NE602 projects and
less available to just a little more complex ones.
An article on the H-Mode Mixer was published in QEX by
IK4AUY ... but I am sure it did not "wake-up" the
interest in too many readers.... (????)

Have a nice weekend and up with the H-Mode Mixer ...
hi

73

Gian
I7SWX

> >
> > Cheers,
> >
> > Julius
> > n2wn
> 
> 
> 



       
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