kopia lustrzana https://github.com/jamescoxon/dl-fldigi
198 wiersze
8.5 KiB
Plaintext
198 wiersze
8.5 KiB
Plaintext
/**
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\page olivia_page Olivia
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\tableofcontents
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fldigi can operate on the following Olivia modes without special setup by the
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operator:
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<br>
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<center>
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Mode | Symbol Rate | Typing Speed | Bandwidth
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:-------------:|:-----------:|:-------------------:|:----------:
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Olivia 8-250 | 31.25 baud | 1.46 cps (14.6 wpm) | 250 Hz
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Olivia 8-500 | 62.5 baud | 2.92 cps (29.2 wpm) | 500 Hz
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Olivia 16-500 | 31.25 baud | 1.95 cps (19.5 wpm) | 500 Hz
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Olivia 32-1000 | 31.25 baud | 2.44 cps (24.4 wpm) | 1000 Hz
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</center>
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<br>
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Unusual combinations of symbol rate and bandwidth can be selected
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using the \ref olivia_configuration_page "Olivia configuration tab".
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<br>
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These are unconnected, simplex chat modes with full time Forward Error
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Correction. Olivia is a very robust mode with low error rates,
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but the penalty can be an annoyingly slow transfer of information. If you are
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a one finger typist then Olivia is your cup of tea. The tones are spaced the
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same as the baud rate, for example 31.25 Hz for the default baud rates. The
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default calling mode is 32-1000. It has the following appearance on
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fldigi's waterfall:
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<br>
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\image html Olivia32-1000.png "Olivia 32/1000"
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\image latex Olivia32-1000.png "Olivia 32/1000" width=3.0in
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<br>
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<b>Excerpts from the web pages of
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<a href="http://www.oliviamode.com/" target="_blank">Gary, WB8ROL</a>
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</b>
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<br>
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Oliva Mode is a little different than PSK, RTTY, and many other digital
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modes. Below are tips on how to maximize your use of this mode.
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<br>
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<b>Disable your software squelch or turn it down as low as you can</b>
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<br>
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Generally turn your squelch setting in your software off or set it as
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low as it will go. You will see some "garbage" letters get printed out
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if there is NO Olivia signal present but it doesn't harm anything. When
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an Olivia signal is there it will start decoding it and print out the
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text without garbage at that time. It doesn't do much good to use a
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digital mode like Olivia that can decode signals -14 db below the noise
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lever IF you squelch it AT the noise level! It would be like
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getting a pair of high power binoculars and using them only in a 10x10
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room with no windows.
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<br>
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<b>Be Patient!</b>
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<br>
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When you call CQ on this mode be patient and wait at least 45-60
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seconds before you put out another call. When the other person who
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hears your CQ clicks on the waterfall it may take 4-20 seconds or even
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longer before they might actually start decoding your signal.
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That varies a lot depending on the software they are using AND value
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they have their Sync Integration Period set to.
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<br>
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The Sync Integration Period setting determines how "deep" the Olivia
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decoding algorithm searches in the noise to get the signal. A
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higher settings takes longer BUT usually decodes with more accuracy -
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at least to a point. However, a higher setting (since it does
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more work and takes longer) will increase the delay factor. So,
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when you finish your CQ and your transmitter switches to receive - the
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station listening to you (depending on his Sync Integration Periods
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setting) MAY NOT finish decoding your CQ for another 4-20
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seconds. The same applies during a QSO when you pass it back to
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the other guy for his turn -- be patient if he doesn't come back right
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away because his software may still be decoding your signal long after
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you stopped transmitting.
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<br>
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It DOES NOT PAY to be impatient on this mode and send SHORT CQ's or NOT
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wait at least 45-60 seconds between CQ's. Generally a a 2x2 CQ
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sent at least 2 or 3 times is going to work much better for you than a
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short one. Below is the normal CQ I use though on real fast Olivia
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formats (like 500/4) I will do a 3x3 and send it 3 times.
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<br>
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<tt>CQ CQ de WB8ROL WB8ROL</tt>
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<br>
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<tt>CQ CQ de WB8ROL WB8ROL</tt>
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<br>
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<tt>CQ CQ de WB8ROL WB8ROL pse K</tt>
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<br>
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<b>Don't set your Sync Integration Period setting TOO high</b>
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<br>
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If you set your Sync Integration Period too high it MAY take minutes
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before your software will start decoding a signal AND there is no or
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little benefit to doing that past a certain point. I usually set
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mine so that the delay factor is abut 15-20 seconds. I can time
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this delay factor by sending a very short test and then when it is done
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and the software switches back to receive - time the number of seconds
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before you see random garbage start appearing on the screen (assuming
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you have your SQUELCH OFF). For the standard Olivia modes like
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2000/64, 1000/32, 500/16, 250/8, and 125/4 that usually means my Sync
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Integration Period is set between 3-5 most of the time. If I use
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the faster formats I set it higher often between 6-10. As long as
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my delay factor is approx. 15-20 seconds. Any higher than that and I
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don't see any real improvement in the quality of the decoding.
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But play with your own settings and see what does best for you.
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If you leave it always on one setting, though, and use standard and non
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standard formats of Olivia you are short changing yourself.
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<br>
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<b>Generally keep your Search (Tune Margin) setting to about 8</b>
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<br>
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The setting of 8 is usually good for most situations and this setting
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is usually not all that critical. However, under a few band
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conditions it might (or might not) help to temporarily adjust
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this. If you find other Olivia signals very very close to you -
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almost adjacent or even overlapping it might help to reduce this
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setting to 4 or even 2. This setting determines how far, either
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side of your center frequency, Olivia will search for a signal to
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decode. If you reduce this when another Olivia signal is close or
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overlapping it may keep it from locking onto the other signal instead
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of yours. Also .... if you are trying to decode an extremely weak
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signal and can't even tell exactly WHERE to click on the waterfall
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because the trace is too faint or non existent then it might help to
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increase this setting to 16 or 32 temporarily. Then it would perhaps
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decode the signal even if you were OFF his center frequency by a large
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margin.
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<br>
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<b>If the slow speed of Olivia bothers you some ...</b>
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<br>
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If you find yourself wanting things to go a little faster then start
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using more (ham) common abbreviations like "hw" for how and "ur" for
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your. Don't waste time sending words like "the" and "and" all the
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time. An example : The weather here is nice and sunny today and
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the high will get to 85 degrees --- instead send : Wx nice + sunny -
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high 85 deg -- No need to spell out everything and use superfluous
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words like the, and, many others. And why use words like HERE and
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TODAY in the above context when the other station already knows you are
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telling the weather for YOUR QTH for TODAY. You aren't writing a
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novel, an article, or in a spelling bee. Also after you establish
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the QSO don't send BOTH calls all the time at the beginning and end of
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every transmission. After the QSO is in progress come back to the
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station like this : .. de WB8ROL -- instead of : W9ZZZ de
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WB8ROL -- and when you sent it back to the other guy send : BTU -
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de WB8ROL KN -- That will help speed things up too. You
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don't need to send the other stations call sign continually to fulfill
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your legal obligation to identify your own station.
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<br>
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<b>Don't be afraid to switch to a NON standard Olivia format if
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conditions warrant it.</b>
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<br>
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If signals are real strong and you prefer to be sending and receiving
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at a faster speed - don't be afraid to ask the other station if they
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would like to speed things up and switch to another Olivia format -
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even a non-standard one. If you, for instance, were talking to me
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on 500/16 Olivia format and we both had very strong signals and not
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much QRM, QRN, etc. then ask me if I would like to go to 500/8 format
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or even 500/4 format. 500/16 format is approximately 20wpm while
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500/8 is close to 30wpm and 500/4 close to 40wpm. If you do end up
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switching to the faster modes you may also want to increase your Sync
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Integration Period setting substantially too - to maintain the best
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quality decoding. If not, you might get more errors in the
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decoded text. And if the band conditions become worse - go back
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to the original format AND remember to reset your Sync Integration
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Period setting or the delay in decoding will be way too long!
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Also, if the band starts getting real crowded and say, for example, you
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were on 500/16 mode - you might suggest to the other station to switch
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to 250/4 mode (increase Sync Integration Period setting too) to save
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space and be a "good neighbor" to all the other operators nearby.
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250/4 is the SAME speed as 500/16 and nearly as sensitive with the
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correct settings.
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<br>
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<br>
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\ref olivia_page "Return to Top of Page"
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<br>
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\ref main_page "Return to Main Page"
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*/
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