Heathkit EK-1

[Ed Lambert" "K1ZOK]

Ah yes, but you have forgotten the most important point.... how the meter
works

The meter works because the current flowing in the internal coil creates
a magnetic field.  This field opposes the field that is present in the
meter movement due to the internal MAGNET.  If the magnet loses it's
magnetism, the meter doesn't work any more.  If the magnetic field is
reduced, the deflection is equally reduced.

The force necessary to return the pointer to the zero position is created
by two spirally shaped springs, which also provide the electrical path to
the coil.  If the springs become damaged due to the meter being dropped,
the spring force is changed, however I would expect this to cause a zero
problem too.

The coil spins on two needle pointed pivots one on either end of the
moving coil.  Sometimes these come out of the support and this causes the
meter coil to be not centered in the field.  This also will cause
erroneous readings.

None of these failures will cause the internal resistance to change but
will affect the meter reading.

Ed
K1ZOK

On Mon, 18 Dec 2000 04:03:45 -0500 Jack Crenshaw <jcrens at EARTHLINK.NET>
writes:
>
> I'm stumped.  I've never seen a meter before that works, that
> measures the right
> resistance, but that doesn't read but a fraction of its rated full
> scale.
>

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