Cecil Moore wrote:
On Jun 2, 5:28 pm, Owen Duffy wrote:
The '259B is no doubt a handy device, but very limited for measuring
components. Have you tried to measure at an inductance that has more than
250 ohms of reactance at some frequency of interest? Have you tried to
explore self resonance of a coil..., invariably it runs into the same
problem of inductive reactance going off scale way below the point at
which self resonance bites in.

Like anything else, there is a limit to the usefulness of an MFJ-259B
but
it is far from useless. Toroids can be characterized by using one or
two
windings to keep the impedance within the 259's range. And self-
resonance
in a coil is super easy. Set the coil up as a base loaded mobile
antenna
without a stinger. Find the first lowest impedance. That's self-
resonance
when the coil is 90 degrees long and the reflected wave is
interferring
with the forward wave at the test point.

Some of the things that limits the usefullness of the MFJ-259B are the
concepts
of the user. If one doesn't believe in (or ignores) the separate
existence of the
forward and reflected waves, then the 259 becomes a lot less useful.
--
73, Cecil, w5dxp.com


Whaddaya mean, "believe in"? If I pray to the waves, will they
bring good luck?
73,
Tom Donaly, KA6RUH