[Elecraft] Measuring SSB RMS Power

[Don Wilhelm]

Ken,

The DL1 is a 50 ohm load.  I did specify that the formula was applicable 
for a 50 ohm load.

For other loads, the formula is Vpeak squared divided by 8R.

It saves the trouble of converting to RMS and then using the more 
familiar Vrms squared divided by R.

If you wish to derive the formula yourself, you can do that, but 
represent the RMS voltage as V time sqrt 2 rather then the approximation 
of 1.414 (or 0.707) which is normally shown.  The sqrt will cancel out 
when it is squared.

73,
Don W3FPR

On 6/20/2019 10:50 AM, Ken Roberson via Elecraft wrote:
>   Don , That may be peak to peak voltage squared decided by 400 for a 50 ohm load.
> Thanks 73 Ken K5DNL
> 
>      On Thursday, June 20, 2019, 9:30:46 AM CDT, Bob McGraw K4TAX <rmcgraw at blomand.net> wrote:
>   
>   Here is a paper on the topic. This covers the correct procedure.
> 
> http://www.eng.auburn.edu/~troppel/courses/TIMS-manuals-r5/TIMS%20Experiment%20Manuals/Student_Text/Vol-A1/a1-12.pdf
> 
> 73
> Bob, K4TAX
> 
> 
> Sent from my iPhone
> 
>> On Jun 20, 2019, at 8:38 AM, John Oppenheimer <john at kn5l.net> wrote:
>>
>> Using DL1 with Oscilloscope to measure KX3 SSB RMS power:
>>
>> https://www.kn5l.net/ssbpower/
>>
>> Question, is this technique correct?
>>
>> John KN5L
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