Hi Peter,
my ARRL Antenna Handbook from 1974 also shows the chart
with the R line orientated vertically,
zero Ohm on top,maximum R on bottom.
My 'Hf Antennas for all Locations' from 1991 has it also vertically
orientaded but vice versa, i.e. zero Ohm on bottom,maximum R on top.
For sure it's just a 'matter of taste' how you rotate the chart.
Maybe the authors thought it would be better for their purposes when
visualizing what they tried to explain.
On the other hand since many decades vector network analyzers (VNA)
e.g. like my HP 8407A from around 1970
always have had zero ohm at the left and infinity ohms at the right on their
display.
So it seems to have become a convention to print the charts with the same
orientation
when VNAs became more common.
73
Clemens
DL4RAJ
----- Original Message -----
From: "Peter Dodd" <[email protected]>
To: <[email protected]>
Sent: Thursday, September 08, 2011 11:12 PM
Subject: LF: The Smith Chart
Earlier literature such as:
The Services Textbook of Radio (1958)
ARRL Antenna Book 14th edition (1984)
HF Antennas for all Locations 2nd edition (1993)
describe a Smith Chart with the centre straight line of R j0 vertically
orientated.
All later and current literature containing Smith Charts show the centre
straight line of R j0 horizontally orientated with maximum R to the right, but
without explanation.
Is there a good technical reason for this change or is it just fashion.
Regards
Peter, G3LDO
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