J M Noeding wrote:
On the other hand one may experience that HP and Tek uses some extra
components which are difficult for the average constructor to explain
or understand the function for,

They don't have a legal obligation to explain their detailed circuit
design... but you can learn a lot by trying to work it out for yourself.

and one may experience that even among the amateurs somebody manage
some technique which almost nobody else can copy - not even very
experienced persons, may I mention SM5BZR Leif's techniques, it is many
constructions, they may look so easy, but one often need some more
deeper understanding to succeed, what say's G3SEK?

I don't have any personal experience of copying Leif's designs (assuming
this is SM5BSZ we're talking about) but they have been widely copied. It
just takes everyone else a whole lot longer... so he's still way out
ahead.


--
73 from Ian G3SEK 'In Practice' columnist for RadCom (RSGB)
http://www.ifwtech.co.uk/g3sek