>
>Rich wrote:
>
>> ? How many peak volts on your 'scope? With "normal" ALC indication, my
>> TS-440S overshoots to about 120v-p. into 50-ohms. .
>
>The actual pulse lasts less than one mS, eyes can't follow and non-
>storage scopes won't display random one mS pulses that occur
>right at the leading edge of envelope rise.
? Oscilloscopes that use a vertical def. delay line can.
>
>If you used a FAST peak-storage wattmeter, you would have a
>clear and accurate indication of overshoot levels. Lacking that, you
>could use a triggered storage scope triggered off the source at
>some early stage, and store about a dozen shots of leading edges
>and find the worse of the batch.
>
? With an oscilloscope that uses a std.-persistence phosphor CRT, one
has around 500mS of persistence to see how high the spike went. My HP
oscilloscope has a 26kV accelerator, so the trace can be made quite
bright in order to stretch the persistence. // To see an ALC attack
spike, I set my oscilloccope to trigger at c. 50v, switch on the VOX, and
speak one word into the microphone. To confirm the peak voltage
measurement, I speak again and watch the deflection on the oscilloscope.
. . An easy calc. gives me the peak W into my 49.8 ohm termination.
For the TS-440, this works out to be c. 144w PEP.
>
- cheers, Tom.
Rich...
R. L. Measures, 805-386-3734, AG6K, www.vcnet.com/measures
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