Discussion in 'Amateur Radio News' started by NN2X, Aug 12, 2018.
Just like Olivia. Only 10y later.
Yes as long as you have a Windows 10 computer. A lot of hams...many many are still running earlier versions of Windows. What's with only Win 10 support? This will segregate out those with less capable computers.
I love Olivia as well, but (-13 dB decoding abilities, while FT8CALL, -24dB)
Also, Olivia (500/8) uses 500 Hz, (Although 30WPM), FT8CALL uses 50 Hz, (Yep only 10 wpm)...
AT least we have the granularity, meaning options. Bad conditions, FT8CALL, better, Olivia, Upward to PBSK, RTTY, and really good SSB on 10 meters DX!
Um, no. That -24dB figure is meaningless, for several reasons, not least of which:
The SNR calculation in WSJT-X is completely unusable. Read the manual to see how it is calculated. It makes all kinds of assumptions that destroy its ability to be compared to anything else -- even other WSJT-X signals. Among other things, it counts all the other signals in the passband as noise, which greatly inflates the SNR performance estimate.
At least half of the information required to successfully decode a signal in WSJT-X comes from outside the radio channel being used. That inflates the SNR performance estimate by at least another 6dB.
Comparing SNR values from WSJT-X with anything else is an exercise in futility.
OK, throw out the math and findings, Try this for size, (And I have many times), I am having a QSO using FT8, and send a direct message to (Through JTX Alert) to have the Ham operator to QSY and use Olivia, 500/8. If I see the signal on FT8 below -13db, I am not able to decode the remote Ham operator using Olivia 500/8, If however, it is above the -13 (On my FT8) I am able to decode the Olivia Mode...Try it yourself, Forget the math...Try in practice...And by the way, I rather use Olivia.
C U on the Bands, NN2X, Tom
I think I'll wait for a controlled-condition comparison to come out on that subject. They have been done for other modes. Adding FT8 would be rather simple to do in the same conditions, although the minimum-SNR copy value would just have to be adjusted upward +6dB when the comparison was finished in order to compensate for the lack of in-band clock.
Not the first time I've heard this great idea. It's something I've explored before and the protocol for FT8Call actually supports it. Reserved for the future
What you have to do here is only compress the words with which you'll get bit savings. E.g., a 16 bit encoding of a word makes no sense if you can transmit the word in 9 bits without the "compression". So, there are many words in that list that should not be included.
The other problem is that many of the QSOs being sent use either non-standard abbreviations or terrible mis-spellings. So, you'd only see the speed improvement if you were a good typist. What an incentive to learn touch typing. Might have to add spellcheck to the tool
These things led me to implement it as it is today, a middle-ground encoding of the most common trigram / quadgrams that could be packed efficiently.
But, still, a dictionary approach would be pretty interesting... we'd probably be able to get a 20WPM average with a 14-bit word identifier.
Want to help out and put together a "ham" dictionary of common abbreviations, words, q codes, etc?
Jordan / KN4CRD
JS8Call (used to be called FT8Call) now uses a form of compression to achieve up to 20WPM.
Upgraded to JS8 yesterday and had quite a few great ragchews on 20 meter. Thanks again Jordan.
I posted before
About the program JS8CALL
It does 15WPM, to 20 WPM....
Here is my take, if you like CW, and can do 20WPM, this does the same, just at -24dB below the noise floor. whereas at very best CW does -13db (And that is really favoring CW with many assumptions)
I always say, that most of the future innovation will be in the digital modes and Jordan (KN4CRD) has really hit a home run!
If you all recall, FT8 was criticized as robotic, no ability to have a real QSO.
Jordan (KN4CRD) created the FT8CALL, and that was great!. With FT8CALL you could have a QSO at 10 WPM while decoding at -24dB below the noise floor while only using 50 HZ Bandwidth!
But Ham operators were indicating 10 WPM is to slow
Welcome to JS8CALL...!
Now the code speed from 15WPM to 20WPM, mean while decoding at -24dB below the noise floor! (50HZ of Bandwidth) / Whereas CW at 20WPM at best is -13dB below the noise floor!
Here is the down load URL
You have to hand it to Jordan, (KN4CRD), this is amazing evolution in digital communications.
Some other great features.
There's a new "selective calling" (SELCALL) mode that you can enable. When enabled, it basically acts like a filter, preventing ALLCALL and BEACONs from being displayed in your RX text area. When enabled, only directed messages to you will be displayed. Along with this, is a new GROUPCALL callsign you can transmit to. It works like ALLCALL, except it will only be printed at stations that are within 100Hz of you. So, if you want to create a round table discussion with a few of your friends, QSY to within 100Hz from each other and send: "GROUPCALL HEY FRIENDS!"
The founder also created a way to manually synchronize your clock time (an adjust your clock drift, if necessary). It's not designed to be used as your primary means of synchronization (you should use NTP or GPS for that if you have it available).
The founder also created a new automatic "BEACON ACK" reply to be sent when you have BEACON mode enabled. It basically works as an automated "ALLCALL?" when you BEACON. This allows you to not have to send "ALLCALL?" manually any more. Just BEACON instead.
With this... stations who reply to you are now marked specially in the heard list so you can find them easily:
That's the benefit of BEACON ACK. All of that happens without intervention from you while you're BEACONing. Very cool.
A couple other things:
* Macros are renamed to Saved Messages.
* You can now save a message you've typed into the TX textbox without having to go into your settings.
* The TX watchdog is renamed to idle watchdog to be more clear with it's intent (and a few bugs with it fixed). If turned on, it'll prevent transmissions when you've been idle for more than N minutes. Useful if you don't want your station transmitting after you step away.
* Better buffering of messages while a station drifts more than a few Hz during message transmission.
There are a ton more features! Just down load and you will get the picture
Tom, NN2X, C U on the bands..