> Rarely does Roger even need correcting, but this is one of those
> times.
No, Roger is correct. Bird's specification is 5% *of full scale*.
That means the Bird's accuracy is +/- 125 Watts *anywhere* using a
2500 Watt element. While in practice the accuracy may be higher
at other places on the scale, the Bird specifications allow that
percentage accuracy may be worse than +/- 5% of the reading below
full scale.
73,
... Joe, W4TV
On 2015-05-03 12:40 AM, Bill Turner wrote:
------------ ORIGINAL MESSAGE ------------(may be snipped)
On Sat, 02 May 2015 21:39:04 -0400, K8RI wrote:
The nearest slug I can find to the legal limit is 2500 Watts. 5% is 125
watts, 125 watts is a bit over 8% (8.333%...)+/- 125 Watts, or
1500-125=1375 to 1500+125= 1625
REPLY:
Rarely does Roger even need correcting, but this is one of those
times.
The 125 watt figure is applicable only at full scale, not part scale.
Assuming the meter is linear across its full scale, the 5% spec
applies to any lower reading. For example, 5% of 1500 watts is 75
watts, not 125.
Most RF meters are not perfectly linear (especially at low scale
readings), but for our purposes we can assume they are close.
73, Bill W6WRT
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