[Amps] 4CX250 IMD

[Peter Chadwick]

carl said:
>Two tone PEP has been mentioned several times as the reference used for the 
4CX250R under discussion.<
But which RCA were talking about, I don't know. They don't say.

>> Nobody has mentioned measurement uncertainty in this discussion, 
> either......

Oh yes it has. I asked how Eimac measured PEP in the 50's. Some of the 
youngsters on here might be surprised to learn that the micropressor driven 
peak reading, self correcting and wash your windows sir, wattmeter hadnt 
been invented quite yet (;<
Plus there's only a few of us old fogies from the pre - digital readout era appear to understand the difference between resolution and accuracy. And an accredited laboratory is expected to a 95% certainty to measure RF power to better than +/-1dB. To a tighter limit, the certainty drops.....So if your wattemeter tells me that the output is 275.123 watts, I'll give you a Bronx cheer! It's like the clock that strikes thirteen - you don't believe any of it. (except in that case, at Saltaire in Yorkshire)
73
Peter G3RZP