On 24 Feb 2007 08:35:28 -0800, "harry"
wrote:

I have recently purchased two different VSWR Bridges.

One was made by Johnson.

The second is a clone.

Both use a fifty ohm resistor in series with the signal path. This
strikes me as a lossy setup. Is there a theory of operation posted or
a text which can explain the operation of the bridge?

Hi Harry,

You don't offer enough information. Some resistance is necessary in
the bridge to terminate the sample collected. It is often 50 Ohms,
and just as often it is not. The actual value is a product of the
bridge configuration.

73's
Richard Clark, KB7QHC