R. Measures wrote:
>
> On Mar 22, 2005, at 11:18 AM, Gary Schafer wrote:
>
>>
>>
>> R.Measures wrote:
>>
>>> On Mar 22, 2005, at 8:16 AM, Gary Schafer wrote:
>>>
>>>>
>>>> ... ... ...
>>>
>> 1. How much peak power do you get when you have 10 volts peak across a
>> 50 ohm resistor?
>> @ 2 watts.
>
>
> Agreed
>
>>
>> 2. What is the average power across that resistor?
>> @ 1 watt. (average power = 1/2 peak power)
>
>
> The question is indeterminate unless the waveform is stated.
>
A sine wave is considered in all of the above calculations.
>>
>> 3. If you find the RMS voltage of that 10 volts peak that = 7.07 volts.
>
>
> Not unless the waveform is stated. For example, the RMS potential of a
> square-wave is not .707 of E-pk.
A sine wave is considered in all of the above calculations.
>
>> What do you get when you find power from the RMS voltage?
>> @ 1 watt.
>>
>> Why would the one watt be average power in one case and RMS power in
>> the other ?
>
>
>
> PEP measurement as used for SSB does not indicate the average power
> delivered to the load, instead, it is the RMS value of the power
> delivered at the instant of the crest of modulation.
>
Yes it is AVERAGE power. Look at the FCC's definition of peak envelope
power. It says average power delivered to the load at the crest of the
modulation envelope over one rf cycle. They do not say RMS power.
73
Gary K4FMX
>>
>> 73
>> Gary K4FMX
>>
>>
>>
>>
>
> Richard L. Measures, AG6K, 805.386.3734. www.somis.org
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