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Re: Making a Q-meter /

 

Jacques, Thanks, makes sense with full scale actually being 3.0. I'm used to AC voltmeters full scale actually being 3.16 even if only marked up to 3.0.

John KK6IL

On 9/20/2022 7:22 AM, Jacques Audet wrote:
John,
The attenuator must adjust levels according to the Q range selected.
To go from a Q range of 30 to 100 requires a level change of 100/30 = 3.333
Attenuation in dB = 20 * log(3.333) = 10.46 dB
To go from a Q range of 100 to 300 requires a level change of 300/100 = 3.000
Attenuation in dB = 20 * log(3.000) = 9.54 dB
Note that to go from a Q range of 30 to 300 requires a level change of 300/30 = 10
Attenuation in dB = 20 * log(10) = 20 dB = 10.46 + 9.54
Jacques,? VE2AZX
ve2azx.net
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