Yes a calorimeter is the better way to measure power. Not inexpensive
however.
Bob, K4TAX
Sent from my iPhone
> On Jul 23, 2019, at 10:07 AM, W2xj <w...@w2xj.net> wrote:
>
> If you really want precision, use a water cooled load. Measure the flow rate
> and input and output temperature. You can precisely calculate power.
>
> Sent from my iPad
>
>> On Jul 23, 2019, at 9:38 AM, Bob McGraw K4TAX <rmcg...@blomand.net> wrote:
>>
>> Since power meter systems are calibrated at a known impedance {usually 50
>> ohms}, and they are voltage sensing devices, any deviation from the
>> calibration value will introduce an error in power indication. It just
>> depends on how precise one prefers to be with power measurements.
>>
>> 100 watts into 50 ohms is 70.71 volts
>>
>> 100 watts into 55 ohms is 74.16 volts
>>
>> 100 watts into 45 ohms is 67.08 volts
>>
>> 73
>>
>> Bob, K4TAX
>>
>>
>>> On 7/23/2019 5:43 AM, CUTTER DAVID via Elecraft wrote:
>>> I often wonder just how useful a precision dummy load really is in the
>>> amateur service. I picked up home brew dummy load at the club the other
>>> day. It measured 57ohms dc and comprises 4 wire-wound resistors attached
>>> in a cluster across the end of the coax. After lots of disparaging remarks
>>> I put it on the VNA and it didn't look at all bad out to 30MHz: nothing
>>> over 1.5:1 and no spikes or dips to indicate resonances. I'll have to do it
>>> again and make a print-out for posterity.
>>> I've heard that salt water in a bucket works after a fashion.
>>> So the question is: how good do you need it to be?
>>> David G3UNA
>>>
>>>
>>>> On 22 July 2019 at 23:58 "hawley, charles j jr" <c-haw...@illinois.edu>
>>>> wrote:
>>>>
>>>>
>>>> Used Bird Attenuator is a good deal.
>>>>
>>>> https://nm3e.com/AttenuatorSampler.htm
>>>>
>>>> Then you’ll have a sample to plug into your counter or scope
>>>>
>>>> Chuck Jack Hawley
>>>> KE9UW
>>>>
>>> ______________________________________________________________
>>> Elecraft mailing list
>>> Home: http://mailman.qth.net/mailman/listinfo/elecraft
>>> Help: http://mailman.qth.net/mmfaq.htm
>>> Post: mailto:Elecraft@mailman.qth.net
>>>
>>> This list hosted by: http://www.qsl.net
>>> Please help support this email list: http://www.qsl.net/donate.html
>>> Message delivered to rmcg...@blomand.net
>>
>> ______________________________________________________________
>> Elecraft mailing list
>> Home: http://mailman.qth.net/mailman/listinfo/elecraft
>> Help: http://mailman.qth.net/mmfaq.htm
>> Post: mailto:Elecraft@mailman.qth.net
>>
>> This list hosted by: http://www.qsl.net
>> Please help support this email list: http://www.qsl.net/donate.html
>> Message delivered to w...@w2xj.net
>
>
______________________________________________________________
Elecraft mailing list
Home: http://mailman.qth.net/mailman/listinfo/elecraft
Help: http://mailman.qth.net/mmfaq.htm
Post: mailto:Elecraft@mailman.qth.net
This list hosted by: http://www.qsl.net
Please help support this email list: http://www.qsl.net/donate.html
Message delivered to arch...@mail-archive.com
