[Icom] FW: [ic756pro2] More on the PEP Test Procedure

[Adam Farson]

Here is some additional input received (with grateful acknowledgement) from
George,W5YR on the test procedure I posted earlier.

1.Prolonged uttering of the word "FIVE!" as in FIIIIIIIVVVVVVVVEEEEE!
provides a particularly useful test signal. The succession of peaks readily
stands out and if the peaks are sharp and clean at their tops, you can be
assured of a clean SSB signal without clipping or distortion.

2. Modest compression or soft peak limiting shows as a gentle rounding of
the speech peaks, rather than the abrupt flat-topping associated with hard
clipping.

3. Also observe the ratio of the total amount of coloured area on the scope
screen whilst speaking into the microphone,  as compared to the CW or RTTY
pattern. That ratio is roughly the difference in average power between the
key-down CW state and SSB. Compression and other processing shows up vividly
as an increase in the amount of coloured area displayed.

4. Note: In the CW modes - CW, RTTY, FM), average power = PEP. In SSB,
depending on voice characteristics, average power may run 50% to 65% of PEP.
In properly-adjusted AM, average power at 100% modulation = 1.5 X resting
carrier power, and PEP = 4 X resting carrier power.

Best 73,
Adam, VA7OJ/AB4OJ
North Vancouver, BC, Canada
http://www.qsl.net/ab4oj/
Note new e-mail address:
mailto:farson@shaw.ca