Richard Clark wrote:
On Sat, 15 Oct 2005 18:25:02 GMT, Cecil Moore wrote:
a calibration cap which has no effect at all on the *physical* reference Z0.

If it had an effect, the Z would change, wouldn't it? The cap has a
Z, that much is sure. The purpose of the cap is not what you ascribe
to it - but that is par for the course as this inclusion quoted above
has no meaning either in or out of context.

Here's a schematic of an MFJ SWR meter at the bottom:

http://www.mfjenterprises.com/man/pdf/MFJ-816.pdf

What do you think is the purpose of the 10pf variable cap
if not to vary the voltage in the voltage divider?

The question is: Between the "transmitter" terminal and
the "antenna" terminal, what determines the physical
characteristic impedance of the sampling circuit?
--
73, Cecil http://www.qsl.net/w5dxp