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LF: Re: Why WSPR when you can SHOUT!

To: [email protected]
Subject: LF: Re: Why WSPR when you can SHOUT!
From: Scott Tilley <[email protected]>
Date: Wed, 24 Dec 2008 11:17:54 -0800
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Mal

I couldn't care less about your out of date qualifications as your profession has been replaced by a black box designed by men like me... That's probably what bugs you the most and what drives your seemingly pointless rants and self aggrandizing behaviour as your skills aren't a viable means to support oneself anymore...

I have no issues with CW as a mode and periodically enjoy using it myself, it is just one FUN aspect of the hobby.

If you dig into the evolution of WSPR as a mode you'll discover that it was only very recently added to the WSJT software package and there exists a separate software package that includes WSPR only, which has evolved in numerous revisions since it was released last spring. Inside WSJT you will find various modes optimized for mostly VHF/UHF modes like meteor scatter, troposcatter and EME. On air testing has demonstrated that WSPR is not a good mode for VHF/UHF due to a number of reasons. Have a look at some of the old threads on the topic from last summer which you'll likely find on WSPR.net. The key to understanding is that all of these modes are tailor made for specific bands and operating conditions and operational purposes. Hence the recent 'experiments' on 600m with WSPR. In my opinion, what you may be noticing is the need for an adjustment in the mode's characteristics to deal with long duration fading on the MF and LF bands. As I observed similar results on Jay's signal the other night.

Everything in life and engineering is a rehash of the old. I for one collect old engineering books and journals to research how things where done in the past to better understand how to use modern technology to deal with present day problems. In my opinion, one must close the loop on how things where done in the past to evolve into the future. The math never changes only the implementation of the math, that's what makes it interesting!

I don't share your pessimistic view of the future or your limited interpretation of what amateur radio is or isn't. I choose to accept anyone that has any interest in the hobby and encourage them to explore what is of interest to them using whatever mode, equipment or technique as long as its legal and done with courtesy. Amateur radio is evolving and it may not be what you want it to be but it is what it is...

73 Scott
VE7TIL












mal hamilton wrote:

The software package that I am using states VHF/UHF and this includes WSPR mode WSJT 7.02 As a professional Radio Office for a life time I have used every communications mode that has ever existed over the past 50 years. You must have missed this info in recent emails. I make the point again that CW has not been bettered in the radio amateur context for exchanging short messages, reports etc in a poor signalling environment. Most of the current modes are reinvented or alterations to what has gone before and taking advantage of modern sound cards and appliance operated computers. One difference now is that there is less operator involvement the PC does all the work and often unattended. These methods are not amateur radio but appliance operator systems like internet exchanges, mobile phones etc. There will be no amateur radio in another 50 years, keep your ears to the ground so many others are saying the same thing. If you need any advice or help with any system old or new just ask and I will be delighted to help.
G3KEV


----- Original Message ----- From: "Scott Tilley" <[email protected]>
To: <[email protected]>
Sent: Wednesday, December 24, 2008 6:05 PM
Subject: Why WSPR when you can SHOUT! was Re: LF: wspr


Mal

WSPR was NOT designed for VHF/UHF and again if you could read you'd know
that after you had read the documentation I referred you to.  It was
designed specifically for HF use in a high QSB environment and it works
very well there.  In fact, it was designed with 30m in mind and the QRPP
beacons that operate there.  I won't bother explaining further as you
don't seem to get the basic premises of signal theory and the techniques
employed for the design rationale of the mode.

Also have a look here for more info on WSPR and the rationale for the mode:
http://wsprnet.org/drupal/

Before I will engage you further in a dialog about this or any other
mode I suggest you do some homework and learn how these modes work.
Like learning CW it takes time and dedication to understand the
technical and operating requirements for these modes.  Just because you
can pound a key doesn't mean you have the right stuff to make any form
of meaningful judgment about this topic.

I suggest you stop wasting bandwidth here and do some learning.   And
then join the dialog with something meaningful.

73 Scott
VE7TIL




mal hamilton wrote:

I did not ask a question about filtering !!!!!!!!!!!!!!!!!!
Oh but you did old man.

What I said was why use SSB mode which is 3 khz wide for a 6hz/200 hz
wide signal when one could take advantage of the receiver narrow CW filter
We do!  But it isn't necessary most of the time!!!!  I told you why
earlier...  I use my 300Hz filter most of the time with WSPR to keep LID
CW ops out of the passband.

, and of course this is filtered further by manipulation of the
soundcard by software. This is old hat technology and not new.
WSPR was engineered for VHF/UHF with plenty of frequency spectrum
available and not MF/LF

WRONG!
squeezed into a 3 khz slot along with other more robust modes
I am not opposed to any particular transmisson MODE but merely
pointing out that the advantage claimed by some for WSPR is not
justified in some cases and my recent observations indicate that I
could have read the transmitted signal had it been ON/OFF CW, instead
I had to wait ages for the signal to improve before text printed. This
was the case last night with WE2XGR where the 2 minute interval trace
was good enough to be read in on/off mode CW but not strong enough to
print most of the time due to slow fade(QSB)

You don't have enough experience or knowledge based on you comments to
intelligently comment on this in my opinion.
I might even research WSPR further for comparison purposes but I
cannot imagine that I will get a print out first before I see a trace.
You have pretty high expectations for the mode!  I have never heard of
any mode that you could decode without being able to see some form of
trace.  Perhaps you're one of these CW op types that has ESP and has
QSOs with the little DX stations in your head?  What don't like the fact
there is something in the world that can quantify reality?




G3KEV

----- Original Message ----- From: "Scott Tilley" <[email protected]>
To: <[email protected]>
Sent: Wednesday, December 24, 2008 5:00 AM
Subject: Re: LF: wspr


If you could read you would do some research at K1JT's wonderful
website:
http://www.physics.princeton.edu/pulsar/K1JT/

Joe has laboured for many a year on similar projects and has written
much about his application of the art.  What you will find is that
research into communication theory that started with CW has taken us
here...

To answer your specific question the filtering is done in software. The
DSP is done in your PC, thereby making filtering in the radio somewhat
redundant unless you have strong neighbours in the passband. So using a
wide SSB filter and the radio in USB makes for easy math in ones head.
Yes, we digital types use our heads from time to time.

Often with modes like JT65 used on EME and now quite popular on HF one
wants as much bandwidth as possible in the receiver so you can monitor
up to the entire band in real time.  So lots of raw bandwidth into the
computer is a good thing...

All BS aside, you may find the technology very interesting to study and
you may find that what you discover is that the spirit of the CW
operator of old is alive and well just evolving with the times.

CW will never die as it has a rich history but it shouldn't be allowed
to impede the growth of new modes and technology.

You should build yourself a Softrock SDR receiver or even a small
transceiver kit and witness a true revolution in radio technology.  My
little 40/30m rig allows me to watch the entire band of either in real
time.  With some new software you can monitor all of the CW QSOs at
once...  Pretty cool.

Not to mention you can plug a key into the little box and do what you
love most and work'm.

73 Scott
VE7TIL










mal hamilton wrote:
If recent published info is correct, this specifies a bandwidth of 6hz
why is USB with a bandwidth of 3 khz necessary to receive this
transmission.
Surely it would be obvious that CW mode was more appropriate where
one could use a narrow filter and dsp processor of a few hertz.
I have asked this question before but never got an answer.
g3kev




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