Posted by
K7TV on
May 02, 2012; 5:41pm
URL: http://elecraft.85.s1.nabble.com/Re-question-for-psk-users-tp7517322p7522944.html
Brian,
You are right! Now people will say, "look I worked this dx with 25 watts, so
that is all you need".
That translates to "you should only work the parts of the world to which the
band is really, really open. Let the band tell you whom you should work".
That is a mindset that can be fine for someone with a lot of empty space in
their dxcc list, but amateur radio in general does not expect you to have a
particular mindset like that. It may fit well for many newer hams that are
also oriented toward digital modes because they are young and prefer
relatively modern technologies. If they are expecting in the long run to
just pick off a few more countries when conditions dictate, and eventually
catch up with those who use the power needed to get the desired
communication now, they might face negative surprises though. A few years
ago QEX had a very technical article that examined various digital modes in
the presence of simulated noise and propagation distortions. A simplified
summary: Some kinds of signal distortions that are common with polar
propagation are extremely detrimental to psk-31. Although psk is reputed to
require much less power than other modes such as RTTY, under those polar
propagation conditions RTTY proved vastly more successful for the same power
level. It seems to me that RTTY is now much more popular than it was years
ago. Could it be that people have found out that the fabulous psk dx results
often cited (and which I too have experienced) do not reflect a general
ability to work all dx locations? Let me add a subjective observation
(opportunity for debate!): After having had only a few home qth's, it seems
to me that a given qth (large area, not street address) favors propagation
to certain other areas. Being near the west coast, I am not at all surprised
at seeing good propagation to JA and NZ, with bounces on salt water. A
little more surprising is the fact that propagation to Washington State
seems to be favored from my Phoenix area. (I am using a beam, so fixed
antenna lobes is not the answer.) Anyway, my point is this: If everyone has
favored propagation paths, for one reason or another, one can either focus
on the easy directions, or use more power. Surely that applies to psk like
any other mode.
73,
Erik K7TV
-----Original Message-----
From:
[hidden email]
[mailto:
[hidden email]] On Behalf Of briana
Sent: Wednesday, May 02, 2012 4:46 AM
To:
[hidden email]
Subject: Re: [Elecraft] question for psk users
Guys,
This rational is bogus. The PSK users have to get used to decoding one
signal at a time with narrow filters if that's what is necessary. To expect
to have 2 or 3 KHz free of strong signals is crazy.
Dealing with this reality puts the burden on the receiving end. No way can
you control what the rest of the wold does. This isn't the Magic Kingdom.
Given that PSK is a narrow bandwidth mode, why not use that to your
advantage?
Other modes deal with strong adjacent signals, why not PSK?
You bought a K3 for its high dynamic range and high adjacent signal handling
capability. Why not use it for this purpose?
Of course the argument ignores all the laws of physics and
propagation. I suggest you run some VOACAP prediction calculations
with 25 watts and look at what you can't work with 25-75 watts. You
may not be interested in working the other side of the world, but others
are.
PSK isn't magic.
73 de Brian/K3KO
______________________________________________________________
Elecraft mailing list
Home:
http://mailman.qth.net/mailman/listinfo/elecraftHelp:
http://mailman.qth.net/mmfaq.htmPost: mailto:
[hidden email]
This list hosted by:
http://www.qsl.netPlease help support this email list:
http://www.qsl.net/donate.html