Posted by
K7TV on
Jun 07, 2011; 5:57pm
URL: http://elecraft.85.s1.nabble.com/KX3-vs-K3-and-other-rigs-tp6443819p6450758.html
Excellent point about seeing 3 times more stars with a gain of 1 magnitude
(although 1 magnitude is 2.5 times brighter, so a little more than 3 dB).
Also an excellent point about 1 dB yielding meaningful results in contest
score even if no difference is discernible in an individual contact. I would
add that if there is an opportunity to get small improvements in several
areas, taking the attitude of looking at impact of a single improvement on a
single contact can likewise lead to missing the big picture. Few of us can
afford going for the last 0.5 dB in every part of a home station. I know I
can't, but doing so is a lot more practical for a portable station. And
getting the results of such a pursuit may be much more important for the
portable station. Here is how I look at my portable capability. While it is
part of the ham hobby, the portable HF radio is an essential piece of safety
equipment for hiking expeditions. (OK, I could get a satellite device, but I
don't like to pay the yearly fees.) When the need for an emergency call
comes, I won't be in a good location, and the time of day won't match the
conditions. My HF radio may not in fact be able to reach anyone at all, at
least not immediately. But when I make decisions about portable gear, I want
to be able to say that I did my best, meaning I went for all those
individual 1 dB improvements that I could, within weight constraints.
Together they will make a difference, and the 7 dB of going from 2 W in my
KX1 to 10 W in a KX3 looks like a no-brainer. (I understand that the KX3
will be able to achieve 10 W using the built-in batteries.) A 30 W amp with
built-in rechargeable batteries would certainly be interesting to look at
too, but may not fit in my packing weight limits.
73,
Erik K7TV
>It is pretty widely accepted in contesting that an improvement in
>*either* receive or transmit capability of 1 dB will yield a useful
increase in the number of QSOs over a 48-hour contest, >even if it has an
indiscernible effect on 99.5 percent of your contacts.
>
>73, Pete N4ZR
>
>The World Contest Station Database, updated daily at
www.conteststations.com The Reverse Beacon Network at
>
http://reversebeacon.net, blog at reversebeacon.blogspot.com, spots at
telnet.reversebeacon.net, port 7000
On 6/7/2011 8:23 AM, drewko wrote:
> There is another way of looking at it-- how many additional contacts
> would potentially be available by utilizing an increase of just 3db?
>
> I don't know the answer but there is a somewhat analogous situation in
> astronomy having to do with the brightness of stars. They are also
> measured on a logarithmic scale, called magnitude, each magnitude
> representing twice or half the brightness level of the following or
> preceding magnitude. A difference of one magnitude does not appear
> very large to the eye, yet the ability to see one magnitude fainter
> can yield three times as many stars. I imagine some similar effect
> might pertain to radio waves.
>
> BTW, I'm not asking for more power in the KX3; would be quite content
> with 10 watts, same as my K3.
>
> 73,
> Drew
> AF2Z
>
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