Thanks to all who responded with great info.
The consensus is that even with the variables, the duty cycle will not likely
be over 50% at my regular contest speed of 30-35wpm.
The reason for my question is that I am evaluating a portable antenna that
claims a 50% duty cycle at 800W,
but drops to 25% duty cycle for CW at 1500W. It appears I should be OK
operating around 600-700W safely with the 50% duty cycle.
This would be used on an island dxpedition where putting up regular (proper)
antennas would not be possible, probably from a villa.
73 and thanks again for taking the time to answer,
Darrell AB2E
________________________________
From: CQ-Contest <cq-contest-bounces+ab2e=hotmail.com@contesting.com> on behalf
of Barry W2UP <w2up.co@gmail.com>
Sent: Monday, July 4, 2022 9:55 AM
To: Paul O'Kane <pokane@ei5di.com>
Cc: CQ-Contest Reflector <cq-contest@contesting.com>
Subject: Re: [CQ-Contest] calculating CW duty cycle
The overall duty cycle DOES vary with speed because the pauses after a CQ,
between S&P QSOs, etc. are relatively fixed spaces independent of speed.
SO, if the CW is faster, there will be less transmit time relative to
listening time.
Barry W2UP
On Mon, Jul 4, 2022 at 7:19 AM Paul O'Kane <pokane@ei5di.com> wrote:
> On 04/07/2022 05:24, AB2E Darrell wrote:
> > Hello all,
> > Can anyone tell me the approximate duty cycle for 30-35wpm CW in a
> contest?
> >
> The duty cycle for CW does not vary with speed.
>
> The standard word PARIS for assessing speed has 50 units, of which 22
> are key down. Therefore, the duty cycle is 44% for an average of 5
> characters per word.
>
> Because some loggers reduce inter-word spacing from 7 to 6 units, the
> duty cycle becomes 22 in 49, which is approximately 45%.
>
> These are worst-case duty-cycle values for contesters, because exchange
> elements (words) are generally shorter than 5 characters. Callsigns
> with 6 or more characters will tend to increase duty cycles, but
> probably never more than 50%.
>
> 73,
> Paul EI5DI
>
>
>
>
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