JT65 on 40M Newby Help

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Need a quick Elmer for JT65.
I have the fabulous  and remarkableFlex 6500 operating just wonderfully on 20M with WSJT-X and JTAlertX (it talks!). So in our current propagation cycle, like everyone, I switch to 40M after 20M dies and I see a ton of really strong signals North (that is, higher) of 7.076 MHz, and like a good SSB operator I set the mode to DIGL. Decodes nothing. Switched tonight to DIGU on 40M and OMG, the heavens open to a ton of strong signals and it starts talking away! YAY!
So, I have learned it is custom to use use DIGU mode on the 40M band that we would regard as LSB, Lower Sideband for phone -- am I correct. And where does one use DIGL?
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David Ahrendts

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Posted 2 years ago

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George Molnar, KF2T, Elmer

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You are correct. USB 
DIGL is not used too often (I hear some FreeDV guys use it 40 and below). RTTY is in LSB, but has its own Flex mode.

Welcome & enjoy! Hope to work you soon.
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Bill Turner

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I never use DIGIL for anything. All digital modes are DIGIU and of course, RTTY has its own mode.

73, Bill W6WRT


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David

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Digital is mostly usb on any band. FreeDV follows voice mode practice even though it is digital.
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Ria - N2RJ, Elmer

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Use DIGU as that turns off all speech processing. WIth DAX the signals are "perfect." 
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YV5WZ

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DIGU  is  .....enjoy it
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dan flynn

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So get ready to loose  sleep.  Now you'll be tracking the grey line on 40 meters till dawn and then back to 20... Enjoy.. hope to work you..
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Al K0VM, Elmer

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In the voice sub bands, it is common practise to follow the voice convention and use DIGL for things like SSTV, EasyPAL & FDV on 40,80& 160.  Outside the voice sub bands, digital modes are  generally all DIGU. Except RTTY which now has is own mode in FLex. 

But there maybe exceptions.

AL, K0VM
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Ria - N2RJ, Elmer

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I did not know that about SSTV. Thanks. 
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Keith Flint

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Your clock may be a bit out of sync with WWV UNIVERSAL TIME. Download and install network time. Or others.
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Ria - N2RJ, Elmer

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Built in time sync may or may not work. Joe K1JT recommends using a better program than the built in time sync feature.

The main reason is that Windows time sync doesn't sync as frequently, or it didn't do so in the past. Dimension 4 syncs much more frequently and Meinberg continuously keeps track of clock skew and syncs (as does the unix NTP daemon in general). 
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David

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Correct Windows client polls weekly by default. That can be adjusted with a regedit. Just don't make it too frequent to avoid becoming abusive to the NTP servers. Here are some links to better understand Microsoft time service and NTP.

HKEY_LOCAL_MACHINE\SYSTEM\ControlSet001\ services\W32Time\TimeProviders\NtpClient SpecialPollInterval 

http://www.windows10update.com/2015/08/windows-10-tutorials-155-change-the-time-synchronization-inte...

https://technet.microsoft.com/en-us/windows-server-docs/identity/ad-ds/get-started/windows-time-serv...

http://www.ntp.org/ntpfaq/NTP-s-algo.htm
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Paul

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Or if not confident in the registry, define a windows task as per my post below.
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Ria - N2RJ, Elmer

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Windows is more like SNTP, as is D4. SNTP does what you describe - it looks at the time returned from the server and makes a massive update at fixed, specific intervals.

Meinberg and other NTP daemons on the other hand, look at the stability of the clock and the NTP sources it is connected to and make corrections on an as-needed basis. This is much better than polling at fixed intervals since corrections are applied gradually and on an as-needed basis. Not all NTP sources are equal, and most of us should be using the NTP pool anyway to spread the load. My eventual goal is to have a stratum-1 on our local LAN using GPS or maybe a WWVB receiver.
(Edited)
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Paul

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Indeed, but that degree of stability is clearly not essential for JT modes. However the frequency of resyncs will be dependent of the stability of the internal clock (and how obsessive one is). Once per hour is more than adequate in my case. YMMV.
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len

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For JT65 use DIGU as others have indicated. I have been playing with WSPR using a Raspberry Pi transmitter with the TAPR board.  You can see the reports on http://dev.wsprnet.org/drupal/wsprnet/map
The TAPR board is http://tapr.org/kits_20M-wspr-pi.html
For 20mW of power, I can do quite well!
WF2V
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Paul

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I have found that it's not necessary to use additional timing applications. The issue with windows native time sync task seems to be that it does not try to sync often enough with your chosen internet time server to be useful for JT modes. However, it's simple to define your own task to do it as often as you like:

https://www.pretentiousname.com/times...

I have mine sync at log on plus hourly after that. My JT timing is never more than 0.5 sec from an average of stations detected in any minute.
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wb7ond

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I like to use NMEATime, when at home in the shack I set it to network, in the park, I set it to use my Holux Bluetooth GPS receiver set out in the bushes.  Only downfall is I have to put a string on the GPS receiver so I don't leave it behind.  It updates the computer and provides it own clock face, has free and paid version.