Bill
I'm not sure this explanation holds water.
The 8 bit D to A will reduce that 1/10th dB resolution from the precision
arithmetic to 114/256 dB or just better than 1/2 dB. Unless the S-meter
movement is really bad, there's something else at work here.
73
Bob, 5B4AGN
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At times my S-meter doesn't seem very accurate, why is that?
Precision arithmetic is used to calculate the S-meter measurements
and the (digital) output is extremely
accurate. The digital S-meter readings can be read over the serial
port using the ?S command. The
s-meter numeric precision is roughly 1/10 of a dB.
The analog meter is the analog representation of the digital S-meter
result. The meter accuracy is affected
by two things. First, the meter is electromechanical and subject to
manufacturing and environmental
variations. Second, the DSP/Logic board drives the meter through an
8-bit Digital-To-Analog converter
which limits the meter to 256 steps.
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The PWR control seems to be fairly accurate
except at the lowest settings. The minimum power I
can set on my Orion is about 4 Watts at a setting of 1.
73, Bill W4ZV
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