"Andre Jute" wrote in message
...
A star ground is just a circular bus or a very short bus. Grounding is
is tricky and tiresome in inverse proportion to the amount of thought
you give it, so I do something between what Iain does and what Patrick
does, and I call it a "star-point". Here you can see my star point
http://members.lycos.co.uk/fiultra/K...0T68MZ417A.jpg
on my T68bis "Minus Zero" amp. It is the short piece of stiff wire
sticking up at the right hand side of the aluminium cased resistor
behind the battery boxes in the centre of the top right hand
photograph. It's the bleeder resistor to the power supply and the star
point is at its 0V end. Notice how the convenitonally drawn schematic
http://members.lycos.co.uk/fiultra/t...17acircuit.jpg
tells you nothing of this, leaving you to work it out for yourself.
All the 0V wires are dropped over this stiff wire and soldered on.
Even on such a short bus I take care of the order of the wires as I
put them on. From this point a wire is taken to main's earth. The case
is connected to mains earth by a wire from very sturdy bolt held in
with serrated washers and nuts, which is placed as near as possible to
the mains socket; unfortunately it is not too clear in the photograph,
but it is just below the switch, near the top right hand corner of the
righthand output transformer in the picture.
Most schematics don't tell you enough about earthing. Here, for
instance:
http://members.lycos.co.uk/fiultra/Jute-EL34-SEntry.jpg
I've shown the star earth being implemented but have not said anything
about connecting the case to earth. Mind you, on some of the Lundahl
Modular Series 300B schemos I showed all the 0V connections in order,
with a note saying "mind the order of the grounding connections", and
two people wrote me letters saying that DIYers are not idiots who need
their hands held. (I was, when I started, and I'm very grateful to
people who made 90 mile round trips to come check over my
constructions before I fired them up.)
Andre Jute
Visit Jute on Amps at
http://members.lycos.co.uk/fiultra/
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Great illustration. Did you have those schematics/illustrations
professionally made or is there a particular program you used? Thanks.
west