[Boatanchors] Using a SG-230 tuner on AM

[Gary Schafer]

Then why are you arguing about and using .006 watts as a reference when
everyone else was talking about a 100 watt transmitter?

> -----Original Message-----
> From: rbethman [mailto:rbethman at comcast.net]
> Sent: Monday, August 10, 2009 3:32 PM
> To: boatanchors at mailman.qth.net
> Cc: Gary Schafer
> Subject: Re: [Boatanchors] Using a SG-230 tuner on AM
> 
> The reference states that you must specify what ZERO - OR - the
> reference point for calculations are based upon.
> 
> You obviously do NOT have any of the references, as the accompanying
> table goes from 6 micro-micro watts up through 6000 Watts.
> 
> It is in power.  I have given the formula, the cited reference by page,
> edition, and date.
> 
> Whether you start with a reference of 0.006 W or start at 100 W, when
> you use the formula, Log Base 10, the results are the same.
> 
> Bob - N0DGN
> 
> Gary Schafer wrote:
> > That person was stating that doubling the VOLTAGE gave a 6 dB increase
> (4x
> > power) in power.
> > The person stating that when doubling the voltage is 4 times the power
> is
> > correct. That would be 6 dB. You can look that up on a dB table that
> shows
> > volts as a reference rather than power. Or take 20 log of the voltage
> rather
> > than 10 log for power.
> >
> > Just do an easy example with ohms law. 100 volts across 50 ohms is 100
> > squared divided by 50 or 10000/50 = 200 watts.
> >
> > Now double the 100 volts to 200 volts. 200x200 = 40000/50 = 800 watts.
> That
> > is 4 times the power. Or expressed in dB that is a 6 dB increase.
> >
> > And yes when you double the voltage across a given load the current also
> > doubles. You can verify that with a little math too. Just another way of
> > expressing that power increases by a factor of 4x.
> >
> > The problem with your table that you reference is that we are NOT
> starting
> > out with .006 watts as the reference.
> >
> > 73
> > Gary  K4FMX
> >