[Elecraft] H mode mixer

[J F]

Hi Gian,


> 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.

Perhaps I missed these, been reading more about
antennas than Rx design, particularly if it was SDR.
Mea Culpa here...


> 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.

I know how this goes, still, if the need and demand
was there, some fee seems better than not having a
good product. Still, maybe it's because many equipment
manufacturers, like many hams, are adverse to change
at times...

> 
> 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.

I am aware of the STAR (had forgot about it) As I
recall there were some personality issues that may
have stunted growth or wider adoption. I could be
wrong...

> 
> 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.... (????)

Actually, I've read IK4AUY's article(s) with much
interest. QEX is not as widely read as say QST or CQ.
These days those types of articles are considered too
specialized for the mainstream. We could use a
publication like "Ham Radio" again. It is rare to see
a RadCom at any but the large hamfests. That seems to
keep technical and non-technical in the same rag,
versus the segmenting that is so popular here.

I might consider modifying one of my K2s (assuming I
don't sell one off for the K3!). It will be
interesting to see how this morphs.

H-mode and tinkering forever ;o)

Ciao bello!

Julius
n2wn