Missed that one Steve, dont you guys use very often the fonetic way to write
?..........1 to 1 hi hi
jos
----- Original Message -----
From: "Steve Katz" <stevek@jmr.com>
To: "'on4kj'" <on4kj@skynet.be>; <amps@contesting.com>; "Bill Fuqua"
<wlfuqu00@uky.edu>
Sent: Thursday, November 07, 2002 10:53 PM
Subject: RE: [Amps] RMS-PEP & 2x8877
>
>
>
> > Adding a bunch to the confusion :
> > Why antenna or baloon constructors say ;
> > Max power ( as an example )
> > ssb/1500 w
> > cw/750 w
> > rtty/500 w
> >
> [Steve Katz] Well, I don't know about Belgium, but here in the
> States, we rate baloons in pounds per square inch, or cubic feet, or
> something like that. I never saw one rated in Watts! <hi hi>
>
> Seriously, this is based on heating effect only. If the limiting
> factor in a component is voltage breakdown, then "mode" would have nothing
> to do with it. But if it's heating, then obviously, RTTY, with 100% duty
> cycle, will create more heat in any dissipative component than CW, with
~50%
> duty cycle, or SSB, with even lower duty cycle than that. Heating is
> usually from IR loss in materials. If the component were lossless, it
would
> have an unlimited power rating...
> -WB2WIK/6
>
>
>
> > Just rember something ( 1950 ) like first derivation and the second
> > derivation of a sine........
> > Why two-tone is used when measuring .....?
> >
> > Jos on4kj
> >
> > ----- Original Message -----
> > From: "Bill Fuqua" <wlfuqu00@uky.edu>
> > To: <amps@contesting.com>
> > Sent: Thursday, November 07, 2002 8:41 PM
> > Subject: [Amps] RMS-PEP & 2x8877
> >
> >
> > > When this came back the columns were messed up. I hope this is better.
> > >
> > > OK enough...
> > > RMS has one meaning, definition or procedure if you want to call it
> > that.
> > > R take square root
> > > of
> > > M the average (mean)
> > > of
> > > S the square of a number of data points
> > > It may look complicated as an equation or an integral expression
> > (calculus)
> > > but it is SIMPLE!!!!
> > > For example...
> > >
> > > Take one cycle of a 1 volt peak sine wave and divide into at least 8
> > > equally spaced points starting at zero degrees.
> > > Calculate instantaneous voltage, voltage squared and power into 50
ohms
> > > load at each point.
> > > Do not use 360 degrees because it is the same point as 0 degrees. You
> > may
> > > do this for any number
> > > of full cycles and you may want to do this on a spread sheet for each
> > > degree (ie 360 points) or what ever.
> > > Phase Voltage Voltage Squared Power into
50
> > ohms
> > > Degrees
> > Watts
> > > 0 0 0
> > > 0
> > > 45 .7071 .5
> > > .01
> > > 90 1 1
> > > .02
> > > 135 .7071 .5
> > > .01
> > > 180 0 0
> > > 0
> > > 225 -.7071 .5
> > > .01
> > > 270 -1 1
> > > .02
> > > 335 -.7071
> > > . 5 .01
> > > totals 0 4
> > > .08
> > >
> > > average of
> > > totals 0 .5 .01
> > >
> > > Square Root of average of
> > > the voltage squared .7071
> > >
> > > The RMS value of the signal is .7071 times the peak (1 Volt)= .7071
> > volts
> > > GEE look at above bold and underlined.
> > > What is the power of this signal into a 50 ohm load?
> > > .7071 volts squared divided by 50 ohms= .01 watts Look again above at
> > the
> > > average power bold.
> > > It is all very consistent with calculations using RMS voltage or
Current
> > > and resistance and power.
> > > Now what happens when we take RMS of the Power??
> > >
> > > Phase Voltage Voltage Squared Power into 50
> > > ohms Power Squared
> > > Watts
> > > 0 0 0
> > 0
> > > 0
> > > 45 .7071 .5
.01
> > > .0001
> > > 90 1 1
> > .02
> > > .0004
> > > 135 .7071 .5
.01
> > > .0001
> > > 180 0 0
> > 0
> > > 0
> > > 225 -.7071 .5
.01
> > > .0001
> > > 270 -1 1
> > .02
> > > .0004
> > > 335 -.7071 .5
.01
> > > .0001
> > > totals 0 4
> > .08
> > > .001
> > >
> > > average of
> > > totals 0 .5
> > .01
> > > .00015
> > >
> > > Square Root
> > > of
> > > average 0 .7071
> > > 0.01225 RMS power
> > ?????
> > > OK above is your RMS power for what ever good it is....
> > > And it does not relate to any of the other numbers you may use such as
> > > voltage, current. resistance or power. But does give you 22.5% bigger
> > > number in this example.
> > > 73
> > > Bill wa4lav
> > >
> > > _______________________________________________
> > > Amps mailing list
> > > Amps@contesting.com
> > > http://lists.contesting.com/mailman/listinfo/amps
> > >
> > >
> >
> >
> > _______________________________________________
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> > Amps@contesting.com
> > http://lists.contesting.com/mailman/listinfo/amps
>
>
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