[BC] "Cusp Rotation"

[Glen Kippel]

BTU is easy to calculate.  Just subtract the kW out from the kW input (from
the AC line) -- the result is the heat given off.  There is a formula to
compute BTU from kW.  I used to have a computer program that would calculate
that, plus the number of CFM necessary to cool the building.  If you are
exhausting the PA heat to the outside, you could subtract that amount and
that gives you the amount of cabinet radiation.

On 3/16/07, Kent Winrich <kwinrich at gmail.com> wrote:
>
> You are expecting the manufacturers to provide this info???
> HAHAHAHA  They dont know half of what they put out.  Heck I couldnt
> even get a simple thing like BTU output from Continental for their
> 816HD (you know so I could spec out an HVAC system??) let alone a
> bunch of measurement points on their own transmitter.
>
> I like the idea of your Vector analyzer.  Sure would be easier than
> going through the OIB and what have you that I did for my two HD
> installs.  UGH.
>
> Kent Winrich
>
>
> On 3/13/07, Phil Alexander
> <<mailto:dynotherm at earthlink.net>dynotherm at earthlink.net> wrote:
> This whole "phase rotation" / "cusp rotation" business
> drives me slightly nuts, because what we are really
> attempting (as best we can) is indirectly "de-rotating"
> or moving the **actual** PA load at the true output of
> the PA to R = x j0 at the operating frequency with the
> sideband frequencies "horns up." Where "x" is the true
> output resistance of the power amplifier(s). IOW it is
> almost like what we did by tuning and loading a tube
> box "back in the day" by operating slightly off
> resonance for best load to yield best modulation b/w,
> except today we must approximate it and set it in the
> blind.
>
> What is really needed is for manufacturers to include
> a dynamic measurement point(s) for the **actual**
> dynamic, complex impedance across the range of operating
> frequencies as seen at the **true** PA output before
> combining/matching to the Tx output spigot.
>
> That is to say something approaching the idea of a
> **true** PA load sample that might be read by a RF
> vector analyzer.
>
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