Peter, I don't know *why* you need a phase-capable
indicating system for use with a bridge - when
a simple 'detection' (diode, meter, etc) will
suffice to detect 'the null' when the bridge
has reached the balanced state ... a simple
diode RF detector outfitted to your favorite
DVM can provide that function ...

Between what two points do you hope to view
the phase and what information might this reveal?

When I do check/memasurement of an series inductor/capacitor
combo across a 50 Ohm line with my network analyzer
I can observe for 1) reflection coefficient at
resonance (also verified by phase 'swing' as the
resonant point is tuned through) as well as observe
where the 3 dB points are in order to determine
circuit Q.

I could read inductor directly by looking at Refl. Coef.
and phase angle then using a Smith Chart (or equation)
compute the actual inductance value.

As to needing 'extra pairs of scope probes' for
a scope for to be used in a particular dedicated
application - I would suggest the use of 'resistive
dividers' in the manner of 'minimum-loss matching
pads' (or even the use of buffer amplifiers!)
designed placed at the output of the DUT (or test
set) and 50 (or 75 or 93) Ohm cable routed for display
on  the O-scope where said cable is terminated in
it's characteristic Z. Many newer/high frequency
scopes also have a termination selection built-in.

The point being, the lowly O-scope should not be
overlooked for some of the more slightly exotic
applications such as observing phase and magnitude
of two signals ...

RF Jim

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