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Part 15 AM transmitter output voltage?

J

JasonW

Guest
Hello All,

What is the voltage at the output terminals (between the antenna and ground terminals, that is) of a 100 milliwatt Part 15 AM transmitter?

I want to try a "no tune" aperiodic resistor-terminated antenna for short-range use. I think a standard 1/4 watt carbon film or carbon composition resistor (maximum voltage 250 volts) will work. The resistor's value is selected to be equal to the transmitter's output impedance.

Many thanks in advance to anyone who can help. -- JasonW
 
> Hello All,
>
> What is the voltage at the output terminals (between the
> antenna and ground terminals, that is) of a 100 milliwatt
> Part 15 AM transmitter?
>
> I want to try a "no tune" aperiodic resistor-terminated
> antenna for short-range use. I think a standard 1/4 watt
> carbon film or carbon composition resistor (maximum voltage
> 250 volts) will work. The resistor's value is selected to
> be equal to the transmitter's output impedance.
>
> Many thanks in advance to anyone who can help. -- JasonW
>
Ohms Law

E = voltage
R = resistance
E/R=I(current)
E x I=P(power)
E x E / R = P
E xE = P x R
If R=50 ohms
If P=0.1 watts
E x E = 50 x .1 = 5
Therefore the voltage is the square root of 5, about 2.23 volts
 
Thank you very much, bossbill! Ages ago in high school science class we touched upon Ohm's law, but only DC circuit examples were given. I wasn't sure if RF worked the same. In any event, the 1/4 watt resistor will work, with plenty of margin to spare. -- JasonW

> > Hello All,
> >
> > What is the voltage at the output terminals (between the
> > antenna and ground terminals, that is) of a 100 milliwatt
> > Part 15 AM transmitter?
> >
> > I want to try a "no tune" aperiodic resistor-terminated
> > antenna for short-range use. I think a standard 1/4 watt
> > carbon film or carbon composition resistor (maximum
> voltage
> > 250 volts) will work. The resistor's value is selected to
>
> > be equal to the transmitter's output impedance.
> >
> > Many thanks in advance to anyone who can help. -- JasonW
>
> >
> Ohms Law
>
> E = voltage
> R = resistance
> E/R=I(current)
> E x I=P(power)
> E x E / R = P
> E xE = P x R
> If R=50 ohms
> If P=0.1 watts
> E x E = 50 x .1 = 5
> Therefore the voltage is the square root of 5, about 2.23
> volts
>
 
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