[Elecraft] Noise bridge

[Ron D'Eau Claire]

A noise bridge seams like a good addition to may test equipment. Home
brew looks like it might be possible for me, but a kit would be nice. I
would like a kit that is complete so I can get on to the projects that I
want to use the bridge for. Ideally, price should to be less that $60.

The Galbraith Noise Bridge
http://www.nzart.org.nz/nzart/branches/chch/branch05/nb-flyer.htm is a
possibility. Has anyone tried this kit? What did you think? I would like
some feedback before I order something all the way from NZ....
Jeff Burns
AD9T

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It depends upon what you are trying to measure, Jeff. They are excellent
for tweaking an antenna into providing a 50 ohm resistive load at some
frequency, or for measuring the amount of inductive or capacitive
reactance the antenna is presenting when it is close, but not exactly
resonant at the test frequency.

But they typically do not provide the sort of range you might want if
you are trying to evaluate any so called "resonant" feeder situation. I
had a Heath Noise Bridge for years and as I recall it was good for
reactance values out to about 100 ohms. A "resonant" feeder situation
can easily present you with values 20 or 30 times greater than that. The
bridge won't give you a clue about what is going on in that case. 

The newer "analyzers" such as those by Autek and MFJ are also fairly
limited in this regard, although probably better than the older Noise
Bridges. Still, their main purpose is for figuring out what needs to be
"tweaked" in an antenna that is designed to present a 50 ohm resistive
load to the feedline.

Ron AC7AC
K2 3 1289