[Elecraft] Feature wanted for W2 wattmeter

[Walter Underwood]

No. That is wrong. Forward and reflected are aspects of the standing wave, not power delivered. —wunder, K6WRU

On Jan 12, 2015, at 8:53 PM, Vic Rosenthal <k2vco.vic at gmail.com> wrote:

> What I want is just forward - reflected. Neglecting losses, this is what the tx is 'delivering'. In real life somewhat less gets to the antenna.
> 
> Vic K2VCO /4X6GP 
> 
>> On Jan 13, 2015, at 3:19 AM, Fred Jensen <k6dgw at foothill.net> wrote:
>> 
>> Well ... sort of.  Some of the reflected power heats up the ATU and/or PA depending on the match it sees [actually, some of the forward power does too, tuners have forward losses].  "Delivered Power" is somewhat difficult to calculate.  Working into a matched, non-reactive load [common for AM broadcast, at least a number of years ago], it's "I squared R" where R is the radiation resistance of the antenna ... and some minor conductor losses in the antenna.  Things get pretty sticky if it's not a matched load.
>> 
>> 73,
>> 
>> Fred K6DGW
>> - Northern California Contest Club
>> - CU in the 50th Running of the Cal QSO Party 3-4 Oct 2015
>> - www.cqp.org
>> 
>>> On 1/12/2015 4:46 PM, Phil & Debbie Salas wrote:
>>> 
>>> Actually, "delivered power" is pretty much what you are measuring.
>>> Remember that reflected power is re-reflected by the source and adds
>>> back into the forward power.  So in your example, you are transmitting
>>> 1200 watts, having 200 watts reflected, then the 200 watts is
>>> re-reflected by the source giving you the 1200 watts.  Of course, there
>>> will be transmission line SWR-related losses.
>> 
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