[Elecraft] Power out on QRP records

[Don Wilhelm]

Tim,
You have the idea of putting the maximum power into an antenna right.
But, a properly designed antenna tuner should have little loss - this is
especially true for 'L-Network' tuner configurations such as those used in
the KAT1 and KAT2.
The real key is to minimize the loss - but a perfectly resonant antenna is
not necessarily the best answer.
The best efficiency is usually achieved by using a low loss feed-line -
especially if it is a rather long run.  Open wire and ladder-line show
little loss even at high SWR, and the loss for RG-213 coax or even RG-8X at
less than 3:1 SWR is not bad either - of course losses in feedlines go up as
the frequency increases and the length increases, but we all knew that!  I
guess the best efficiency would be with a zero length feedline, but then
radiation on low antennas gets absorbed in the nearby ground - so maybe K2
remote will allow us to put our transmitter at the antenna feedpoint <g>
(Anyone know of an effective weatherproof housing?)  Even if we are QRP, it
does not make much sense to me to use a lossy feedline unless the goal is a
lightweight setup for portable operation - physically large feedlines are
usually more efficient.

I could go on for hours on this - but I will end by saying that if the power
is going out of the transmitter, all that power - minus the feedline loss -
will be radiated by the antenna.  (That is the conservation of energy
principle, and if anyone here wants more discussion off-list, I will happily
consent to all except for flames).

73,
Don Wilhelm  - Wake Forest, NC   W3FPR home page: http://www.qsl.net/w3fpr/
  QRP-L # 485   K2  SN 0020   mailto: w3fpr@arrl.net

----- Original Message -----
> Hi folks -
> To continue from my earlier question re the K2 and external power
> meters: When heavy duty QRP types talk about power out and setting miles
> per milliwatt records - is it based on the power that goes to the ATU on
> a rig like the K2 or the K1? I guess the answer has to be yes - but if
> they are heavy in to competing they would be using that power more
> efficiently by bypassing a tuner and going to a perfectly resonant
> antenna - do I have the idea right? Thanks folks. 73/Tim Logan KB7OEX