[Elecraft] K2 Power indication, CW vs SSB question

Wed May 7 13:28:00 2003

The confusion seems to come out of a decision by the ARRL to consider 10
watts PEP equivalent to 5 watts CW for "QRP" power levels.=20

I believe that the QRP ARCI defines QRP as 5 watts our less output =
either
PEP or CW.=20

When you set the power output on your K2, you are requesting either CW =
or
PEP, depending upon the mode. The bargraph shows you the PEP output in =
SSB,
and you will see that the 5 watt bar will just flicker on occasion when =
you
transmit SSB with the power set to 5 watts. If you want to run 10 watts =
PEP,
set the POWER control for 10 watts.=20

The difference is 3 dB or half an S-unit. By itself  that's an almost
insignificant difference. That difference can matter when striving to =
work
"by the rules" or when digging for every dB of system performance. To
paraphrase the old saying, "A dB here, a dB there and pretty soon we're
talking about a real power!"

Some ops are pretty... uh... "rigid" about setting the power output to
exactly 5 watts. In the "real world" out there, a power difference of a
couple of dB is undetectable on the air. Dedicated QRPers, wanting to =
know
that they won their awards and scored the points in the contest in the =
true
tradition of "5 watts or less!", tend to err on the low side. They often
hook up the best power meters available and set the power a closely as =
they
can to 5 watts, being very careful not to go a milliwatt over 5 watts
output.=20

Other ops look at the 5 watt limit rather like some automobile drivers =
look
at the speed limit on a road with no police around. And that's a good
analogy. It's a matter of doing "what's right" that agrees with our =
sense of
personal ethics. Where's the joy in a high contest score or a QRP award =
if,
when we look in the mirror we see someone who knows that we cheated?=20

I'd have a very hard time if any one complained that I wasn't running =
"QRP"
when I had the K2 power output set to 5 watts on the bargraph. That =
metering
is accurate to 20% or better... and that's a difference of only 1 =
watt....
or less than 0.8 dB.... or only about 1/10th of one "S" unit!=20

Very few "Ham" wattmeters are more accurate than that. Many are a good =
deal
worse. And who is to say that if the meter is off by 20% that I am not
actually running 4 watts rather than 6 watts?

Ron AC7AC
K2 # 1289

-----Original Message-----
From: [email protected] =
[mailto:[email protected]]
On Behalf Of [email protected]
Sent: Wednesday, May 07, 2003 9:23 AM
To: [email protected]
Subject: [Elecraft] K2 Power indication, CW vs SSB question

A trivial question re K2 Power Out indication, CW vs SSB.

In contesting activities, the published rules typically indicate some
maximum power out to operate in a particular entry catagory. For =
example,
5-watts is the usual QRP max power. Some SSB mode contest rules may even =
say
10w PEP.

My practice has been to dial up 5 with the POWER knob and let her rip. I =
am
trusting that this is 'close enough' and have no other means of =
measuring my
actual power out.

So the question I raise is.....  Is this dialed up '5' a DC power (i.e. =
CW
mode) and what about SSB mode... would the '5' indicate PEP power, or am =
I
actually running some other power out value in SSB? What would I dial up =
if
I wanted to run SSB, say, 10-w PEP?

Inquiring minds want to know...
de Jerry/k6iii
San Jose, CA
K2 #500
_______________________________________________
Elecraft mailing list: [email protected]
You must be a list member to post to the list.=20
Postings must be plain text (no HTML or attachments).=20
See: http://mailman.qth.net/mailman/listinfo/elecraft
Elecraft Web Page: http://www.elecraft.com