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That "0.707" is for the peak of a sine wave.

Not the same thing as your AM modulation envelope.

If what you want is a peak modulated power reading, that is NOT the same thing at all.

You can only calculate the PEP of your AM transmitter's modulation envelope with a 'scope or peak-reading meter. An average-reading meter alone won't tell you this, no matter how sincerely you want it to.

The 'scope method is easy. You'll need a radio that can deliver a carrier at least four times the carrier power of the radio you want to measure.

Modulate the radio. Make a mark on the 'scope screen at the highest point the modulation peaks reach on the screen.

Now disconnect that radio. Connect the bigger radio, and turn up the carrier until IT reaches the mark on the screen. Don't modulate it, you only want the carrier for this measurement.

Now that the second radio's carrier shows the exact same spot on the scope as the first radio's peaks, read your average wattmeter. This is what the first radio's PEP will be.

73

<blockquote data-quote="nomadradio" data-source="post: 605655" data-attributes="member: 22">That &quot;0.707&quot; is for the peak of a sine wave. Not the same thing as your AM modulation envelope. If what you want is a peak modulated power reading, that is NOT the same thing at all. You can only calculate the PEP of your AM transmitter&#039;s modulation envelope with a &#039;scope or peak-reading meter. An average-reading meter alone won&#039;t tell you this, no matter how sincerely you want it to. The &#039;scope method is easy. You&#039;ll need a radio that can deliver a carrier at least four times the carrier power of the radio you want to measure. Modulate the radio. Make a mark on the &#039;scope screen at the highest point the modulation peaks reach on the screen. Now disconnect that radio. Connect the bigger radio, and turn up the carrier until IT reaches the mark on the screen. Don&#039;t modulate it, you only want the carrier for this measurement. Now that the second radio&#039;s carrier shows the exact same spot on the scope as the first radio&#039;s peaks, read your average wattmeter. This is what the first radio&#039;s PEP will be. 73</blockquote>

[QUOTE="nomadradio, post: 605655, member: 22"] That "0.707" is for the peak of a sine wave. Not the same thing as your AM modulation envelope. If what you want is a peak modulated power reading, that is NOT the same thing at all. You can only calculate the PEP of your AM transmitter's modulation envelope with a 'scope or peak-reading meter. An average-reading meter alone won't tell you this, no matter how sincerely you want it to. The 'scope method is easy. You'll need a radio that can deliver a carrier at least four times the carrier power of the radio you want to measure. Modulate the radio. Make a mark on the 'scope screen at the highest point the modulation peaks reach on the screen. Now disconnect that radio. Connect the bigger radio, and turn up the carrier until IT reaches the mark on the screen. Don't modulate it, you only want the carrier for this measurement. Now that the second radio's carrier shows the exact same spot on the scope as the first radio's peaks, read your average wattmeter. This is what the first radio's PEP will be. 73 [/QUOTE]

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