Posted by
John Oppenheimer on
Jun 20, 2019; 3:34pm
URL: http://elecraft.85.s1.nabble.com/Measuring-SSB-RMS-Power-tp7653233p7653238.html
Hi Don,
On 6/20/19 9:21 AM, Don Wilhelm wrote:
> John,
>
> That connection is OK if you realize that your scope is reading the DC
> voltage developed by rectifying the RF from 1/2 of the load. You still
> have to use the power formula that is in the DL1 manual.
Well yes, power references are DCV^2 / 25
DdB ratios computed using voltage ratios in the form of
20 * Log(v1/v2). For example, 0 compression Pep/Pav dB =
20 * log(15.3/5.24) = 9.3. I do need to flip the table title to Pav/Pep
for proper negative dB values, Done.
> I prefer to allow the 'scope to read the full peak RF voltage. Connect
> the 'scope probe to the side of one resistor which is connected to the
> BNC jack (one of the leads closest to the BNC), and the 'scope ground
> probe to one or the resistor leads furthermost away from from the BNC jack.
Using detected RF envelope for oscilloscope average RF measurement at
each digitized point during long, six second, trace. This will result
with increased accuracy when measuring modulated speech.
John KN5L
> On 6/20/2019 9:38 AM, John Oppenheimer wrote:
>> Using DL1 with Oscilloscope to measure KX3 SSB RMS power:
>>
>>
https://www.kn5l.net/ssbpower/>>
>> Question, is this technique correct?
>>
>
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