Lamb wrote:
>
> I think for EME work, good means putting out enough power to be barely heard
But Rick did say 'good linearity' not 'good power'. He defined the power
(900 W), but it was the linearity to which a rather subjective measure
(excuse the pun) 'good' was used. I'm trying to make the point that
there is little to be gained by arguing about how much power a 4CX250B
can produce, without defining at what linearity this is to be taken.
I've seen numerous audio devices rated at huge output powers. Maybe '100
W music power'. Then in the small print they might (if you are lucky)
quote something like '10 W RMS. at a THD of 10%'. Nobody wants to listen
to much that has 10% distortion, so really it is not capable of
producing 10W at what most people would consider acceptable distortion.
Without some specification of distortion, the power rating of a "linear
amplifier" is rather pointless.
I could say my computer has good performance (it is a Sun SPARCstation
20 with 4 x 125 MHz CPUs and 448 Mb RAM). Its performance is more than
adequate for most things I do, but hardly acceptable for modern-day
weather forecasting. Good is subjective.
Subjective words like 'good' are fine in everyday usage, but when people
are arguing about the finer points of the 4CX250B, then I feel that
'good' should quantified.
--
Dr. David Kirkby Ph.D,
email: drkirkby@ntlworld.com
former email address: davek@medphys.ucl.ac.uk
web page: http://www.david-kirkby.co.uk
Amateur radio callsign: G8WRB
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