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Potential Bug? fldigi instances not closing out in Windows

 

Mostly addressed to Dave (W1HKJ) but also looking for others experiences:
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Scenario:
I am now running current alphas of fldigi and flrig (autostarted) on a gamer Win11 workstation, but have seen this issue? going back several "final" releases and on a Win10 workstation. I use multiple instances of fldigi talking to a single instance of flrig because flrig can do KISS protocol and can control a single rig for multiple instances of fldigi looking at that rigs sound CODEC stream.
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Before the "frequent commentators" ask, I have had poor luck setting up the other rig control engine because they either did not work at all for my use case or were a mess to configure. I have seen the problem with the other control engines. I will be using flrig.
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I can start a single instance of fldigi with flrig and they will close out normally most always. The trouble does start after long (days) running the apps.
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When two or more instances are running with or without flrig, I can almost always shut down the second instances, but the primary instance will shut down (autostarted) flrig but then hang and require one the "messy exit" routines to kill the hung process. This problem happens very often as quickly as 15 minutes or less after the programs are started.
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Quite a while ago I tried capturing the hang event unsuccessfully - probably because the hang suspended the debug logging writes?
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@Dave: What is best way to log this event when it happens?
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@All: have you seen this same scenario when running multiple instances of fldigi either with separate instances of flrig (as in for two different radios) or a single instance of flrig hosting multiple instances of fldigi?
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Jack Spitznagel
KD4IZ - FM19OO
Parkton, MD


#flrig #flrig

 

correction...correction
i copies and pasted wrong info..
here is correct..
jim
?
i noticed a problem with wsjt-x and flrig with my ic7300
sometimes when i switch to a different config i had saved...
wsjt-x would not connect with rig ctl...it wanted me to
reconfig rig ctl...
after looking over my wsjt-x settings...i noticed that
rig settings looked different.
some rig settings were..
fd\Configuration\Rig=FLRig FLRig
and some rig settings showed..
Default\Configuration\Rig=FLRig IC-7300(FLRig)
?
?
fix...
i loaded the lastest wsjt-x 2-7-0
updated hamlib..
then removed flrig before i reloaded it...same level..2-0-05
deleted all my configs...then created all new ones...
all the rig settings now show?
Rig=FLRig IC-7300(FLRig)

jim
wa4yiz
?


#flrig #flrig

 

i noticed a problem with wsjt-x and flrig with my ic7300
sometimes when i switch to a different config i had saved...
wsjt-x would not connect with rig ctl...it wanted me to
reconfig rig ctl...
after looking over my wsjt-x settings...i noticed that
rig settings looked different.
some rig settings were..
fd\Configuration\Rig=FLRig FLRig
and some rig settings showed..
Default\Configuration\Rig=Icom IC-7300
?
the fix...
i loaded the lastest wsjt-x 2-7-0
updated hamlib..
then removed flrig before i reloaded it...same level..2-0-05
deleted all my configs...then created all new ones...
all the rig settings now show?
Rig=Icom IC-7300
jim
wa4yiz
?


Re: Second instance#help #windows11

Randy VE3JO
 

Hi Jack, yes I did get some ideas and also reread the manual and now my qmx will operate with FT8CN for ultra portable operating. I will let you know if I get it working with fldigi. I want to use it in areas where I can carry the laptop, I would like to use Feldhell and Olivia for some park activations. I wish there was an android app for the other digi modes for going portable.
?
Randy
VE3JO


Re: Second instance#help #windows11

 

开云体育

Randy,
Let me know how it goes. I have a QMX+ that I need to configure on a Win11 laptop.
I saw that you had asked a different question on another forum. Did you get an answer there?
Jack Spitznagel
KD4IZ
FM19oo
Parkton, MD
On 2/20/2025 12:30 PM, Randy VE3JO via groups.io wrote:

Thanks for the help, I understand how to do it and have created a second path for my QMX. When I get home this evening I will get it connected and hopefully setup and running.
?
Randy
VE3JO


Re: Second instance#help #windows11

Randy VE3JO
 

Thanks for the help, I understand how to do it and have created a second path for my QMX. When I get home this evening I will get it connected and hopefully setup and running.
?
Randy
VE3JO


Re: Second instance#help #windows11

 

开云体育

Randy,

Sometimes a "step by step" says it best. You can make fldigi run in multiple "instances" - at the same time. Only one copy of fldigi.exe needs to be on your computer. My situation: I use both a 7300 and a 705 on digital and I have multiple fldigi instances configured that I can use just for the rigs I want to use.

WHy and How? >>> fldigi can create a new configuration directory if you add a bit to the target line. For each instance you can customize for the purpose you want without copying the fldigi .exe file or the main install directory.

To Do This:
1. Copy your fldigi icon.
2. Paste two? or more copies onto the desktop. Rename each to something you will remember it by like:
"flrig 2.0.05.93 IC-7300A" and
"flrig 2.0.05.93 IC-705" for example
3. Open the first icon copy properties settings by right clicking the icon and selecting Properties.
4. You will see something that looks like this:

5. Add something like this to the end of the Target line:? --config-dir C:\Users\"your username"\flrig.ic7300A so the whole line reads:
"C:\Program Files (x86)\flrig-2.0.05.93\flrig.exe" --config-dir C:\Users\"your username"\flrig.ic7300A
?- You should change the "your username" bit to your username (if you don't know it, you can find it on your log in panel or by going to the C:\Users directory and looking at the filename there. Use the model number of your rig like"ts590A" or "ft818A" so you know what rig you're configuring. I use the A, B, etc because I often run more than one instance per rig.
?- My full Target line looks like this: "C:\Program Files (x86)\flrig-2.0.05.93\flrig.exe" --config-dir C:\Users\jspitzn\flrig.ic7300A
NOTE: make sure you use -- (dash dash) before "config-dir" or just copy and past the line then edit it for your needs.
6. Click on Apply at the bottom of the panel. Then close the panel by clicking "OK".

Repeat the steps above for the second copy of? the icon - in my case that would be for my ic705 so the Target line would look like:
"C:\Program Files (x86)\flrig-2.0.05.93\flrig.exe" --config-dir C:\Users\jspitzn\flrig.ic705

When you double click on each of the new icon copies, a new config directory is created and you will be asked to configure fldigi like you would for a new install.

!I don't advise you do this at first! >>>However: If you want to start with the same settings that you have for your original instance of fldigi, you will need to copy the entire original default config directory into the new config directory. This can create some other issues for first time multi-instance users that I don't want to discuss in this email.

Good luck!

Jack Spitznagel
KD4IZ
FM19oo
Parkton, MD
On 2/19/2025 12:03 PM, Randy VE3JO via groups.io wrote:

Could some one please explain to me step by step how to create a second instance of fldigi on windows 11. For some reason I am not grasping the concept. I would like to have another setup for my qmx to use portable.
?
Thank you
Randy
VE3JO


Re: Second instance#help #windows11

 

Hello Randy,

Please refer to my topic 2 below.

Regardless of the OS version, by creating different shortcuts referencing to different data folders, you can configure and run 'independent' instances of a single standard fldigi program installation.

Note the renark about 'TX' though!


Good Luck!


73s Tobias
.-.-.



FLdigi Easy Living - a few practical remarks...


Hello FLdigi Users,


This concise information is for those seeking to restore Basic FLdigi (programs family) Functionality, usually after a program or operating system update, or simply interested in a Portable Installation. Other topics mentioned below include operating multiple FLdigi Instances, FLdigi Configurations and rearranging Macros.


- - - - - -


1. Portable 'thumb drive' Installation, also useful to Restore Basic FLdigi Functionality (from scratch)...


After several updates (especially when skipping a few releases), or even moving FLdigi from one PC (hardware or OS) to another, configuration files may sometimes become incompatible and cause unintended issues. To overcome this and create a truly 'fresh' basic installation, you may wish to try out the 'FL_APPS' folder install feature. For this to work, it doesn't matter where this FL_APPS folder resides, e.g. a path like 'C:\Apps\Radio\FL_APPS' will do, if FLdigi is installed directly therein.

The special 'FL_APPS' folder feature has originally been programmed into FLdigi in order to allow creating a 'portable' FLdigi installation, e.g. on a memory stick. The key for this to work is this special folder name, which by definition triggers FLdigi, if installed into 'FL_APPS', to place all the necessary config files and others as sub-folders therein, contrary to the 'standard' installation, where the 'fldigi.files' with personal user preferences, macros, logs etc. are generally stored in the classic location 'C:\users\<UserName>fldigi.files' and several sub-folders.

A detailed description can be found in the online 'Fldigi Users Manual 4.2.00', in the chapter 'Installing fldigi on a thumb drive'.
This highly recommended Fldigi Users Manual can also be downloaded separately for local use. It has a 'Contents Index' helping to find your way within.


- - - - - -


2. Multiple FLdigi Instances (intended for use with a standard installation)...


There is a versatile feature which may be useful for various reasons, provided FLdigi is already present and (at least partly) operational on your system.

By creating several different shortcuts, you can, quite independently, configure and use multiple different FLdigi instances on your local hard drive, all using the same FLdigi installation (e.g. fldigi.exe etc).

Caution: In case you apply rig control or transmitting of any kind, make sure that only one (1) single FLdigi instance is active in this respect at any given time!

In the above-mentioned FLdigi documentation, you'll also find a chapter 'Operating Multiple Copies', which involves launching FLdigi via a batch file or shortcut link that includes a command line switch, for example:

--home-dir FOLDER --> Set the home folder to full pathname of FOLDER
fldigi will put the file stores fldigi.files, and nbems.files in this folder
The default is: C:\Users\<UserName>\

--config-dir FOLDER --> Look for configuration files in FOLDER
The default is: C:\Users\<UserName>\fldigi.files\


In practical terms, proceed as follows:

- On the desktop or in your windows file manager, perform a mouse 'right-click' (or hit the 'AppsKey', if available).

- Select 'New -> Shortcut'

- In the 'Create Shortcut' dialog, browse or enter/paste the path to your installed FLdigi.exe file, e.g. 'C:\Apps\Radio\FLdigi\fldigi.exe'.

- Behind this path, after a <SPACE>, enter one of the 'command line switches' as given above, e.g.
'C:\Apps\Radio\FLdigi\fldigi.exe --home-dir C:\Apps\Radio\FLdigi\MyConfig'.


All valid command line switches of your current FLdigi installation can be browsed and written into a text file (as a reference) as follows:

fldigi.exe --help >help.txt

If you can't open a command window directly from within the 'FL_APPS' (or your standard FLdigi) folder, simply write the line above into a plain text file, call it 'gethelp.bat', then run this gethelp.bat and, once complete, open the newly written 'help.txt' in the same folder. This file should contain all the available command line options to choose from.


- - - - - -


3. Verify where FLdigi retrieves and stores configurations, data, and macros...


In case of uncertainty or after using any of the options described above, it's a good idea to verify, directly from the Main Menu, where FLdigi has located (and uses) its respective data.

Menu - File - Folders - Fldigi config... => This will open the respective folder, e.g. 'C:\Users\<UserName>\fldigi.files' for a standard installation.

Menu - File - Macros - Open... => This allows loading a Macro definition saved before, e.g. from 'C:\Users\<UserName>\fldigi.files\macros'.


- - - - - -


4. Config Scripts...


On a related note, once you have defined a functional FLdigi configuration and wish to preserve it for future use, save it as follows:

Menu - Config Scripts - Generate => Save it in a suitable location, e.g. 'C:\Users\<UserName>\fldigi.files\scripts\default_script.txt'.

This may be done several times for various different sets of macros, audio devices, or other settings you use, and it may be recalled again from within FLdigi via:

Menu - Config Scripts - Execute => Open an existing script file, e.g. 'C:\Users\<UserName>\fldigi.files\scripts\USB_Audio_script.txt'. It loads instantly without restarting Fldigi.

Note: Config Scripts are a summarized compact data file which contains all your Macros and numerous other Settings, but not all rather specific ones for individual modes etc. If unsure about a specific setting, open the file and search for it. It may also contain actual file paths (e.g. under NBEMS the one for 'flmsg.exe' and, if defined within Macros, these as well). So if you plan moving an installation around and benefit from re-loading a formerly functional Config Script, make sure to review the script file and adapt your paths to match reality. Searching for ':\' should usually take you to the next path in the definitions, if present. Since the UNIX notation may also be used, also check for ":/" to find further file paths.


- - - - - -


5. How to 'easily' Rearrange Macros...


If you wish to move / rearrange your existing Macros, it is easiest to save your current Config Script as shown above, open it in a plain text editor (e.g. Notepad), and quickly make the necessary changes therein.

Note that the Numbering for the Button Sequence per Macro is quite straightforward, just consisting of the Macro Button Row (1...4, top to bottom), and the Macro Button Column (1...8 per row, left to right). Example for the Top Row (1) and the 3rd Macro Button (column 3):

MACRO:1,3,"THOR25"
<MODEM:THOR25>
END:

Then just swap out or alter the respective numbers between the Macros you wish to rearrange. Don't care about the (then illogical) Macro position in the text, only the numbers allocated to each Macro Definition (e.g. MACRO:1,3,...) actually matters for FLdigi. But keep track separately of what you swap to avoid creating double or missing numbers entries!

Practically, to swap the first top 4 with the next top 4 Macros, change (in sequence top - down, which in fact only means changing a total of 8 digits):

1,1 => 1,5 >>>> this shifts the 4 leftmost Macros to the 4 center Buttons.
1,2 => 1,6
1,3 => 1,7
1,4 => 1,8
1,5 => 1,1 <<<< this shifts the 4 Macros from the center Buttons all the way to the left.
1,6 => 1,2
1,7 => 1,3
1,8 => 1,4

If you wish to swap rows, instead alter the 1st figure accordingly, per Macro Definition.

Save the text file as a new Config Script, e.g. 'C:\Users\<UserName>\fldigi.files\scripts\Macros_Rearranged_2025-02-14.txt'.

In FLdigi, open the modified script file via Menu - Config Scripts - Execute.

Check that everything is and works as intended.

Finally, you may then (once) save the modified script file again via Menu - Config Scripts - Generate. This will automatically 'restore order' in the script file (just for future use, this step is functionally not necessary), by auto-sorting the columns and rows along with their respective Macro definition nicely in their 1...N numerical ascending order. In other words, without any effort, your new Macro sequence is now stored as if you had awkwardly re-sorted everything yourself in the process of the file editing described above.



I hope these few simple concepts may help you use and enjoy FLdigi and Ham Radio even more!


73s SWL Tobias
.-.-.
Am Mittwoch, 19. Februar 2025 um 19:46:44 MEZ hat Randy VE3JO via groups.io <rcoulas67@...> Folgendes geschrieben:


Could some one please explain to me step by step how to create a second instance of fldigi on windows 11. For some reason I am not grasping the concept. I would like to have another setup for my qmx to use portable.
?
Thank you
Randy
VE3JO


Second instance#help #windows11

Randy VE3JO
 

Could some one please explain to me step by step how to create a second instance of fldigi on windows 11. For some reason I am not grasping the concept. I would like to have another setup for my qmx to use portable.
?
Thank you
Randy
VE3JO


Re: How do I use all the OFDM modes?

 

I would also like to point out another technicality about the OFDM modes in FLDigi in general. They technically are just multi-carrier modes, not OFDM. OFDM means that the spacing of the carriers is such that the center frequency of each carrier is located at the zero points (nulls) of each adjacent carrier. This produces a spectrum with a flat top. However, in FLDigi, the so-called OFDM modes are such that the zero points (nulls) of each carrier are located at the nulls of the adjacent carriers. So this makes them actually not true OFDM modes. Please fix this. You could get higher data throughput (or at least reduce the bandwidth) if you were to cut the carrier spacing in half, so that they were true OFDM modes where each carrier was located at the null of the adjacent carriers.

On Mon, Jun 24, 2024 at 11:56?AM Robert, KK5VD via <kk5vd=[email protected]> wrote:
The current 3 modems are sufficient for testing. The other OFDM modems flat out don't work. No point in using them until they get fixed.

Robert






Re: XEIGO G90 SETTINGS? #fldigi

 

开云体育

Hey Dave thanks for the reply. Well finally after checking my settings I now have full 20 watts out. Works great now.

Appreciate the help.

Dave

On 2/16/2025 1:12 PM, Dave Garber via groups.io wrote:
I use both quite often

sent by ve3wej on samsung s21+

On Sat, Feb 15, 2025, 4:52?p.m. David Tucker via <nu4ndave=[email protected]> wrote:
Any one know how to use Any Desk or Team Viewer to look at my settings for PSK in my computer?
Thanks
--
73's de NU4N
-- 
73's de NU4N

--
73'S DAVE NU4N


Re: XEIGO G90 SETTINGS? #fldigi

 

I use both quite often

sent by ve3wej on samsung s21+

On Sat, Feb 15, 2025, 4:52?p.m. David Tucker via <nu4ndave=[email protected]> wrote:
Any one know how to use Any Desk or Team Viewer to look at my settings for PSK in my computer?
Thanks
--
73's de NU4N


Re: Sending Pics

 


Hi Randy,

First of all, the mismatch between the speed factor displayed on the button and the actually used one is what I had described before, saying 'Note that the figure indicated on the button is not always in synch with the chosen mode'. I don't know why this happens, it might be a bug of some sort. That's why I recommended 'So better try it out before actually going on the air'.


The setting should make a very noticeable difference in TX/RX speed, but while the Button only affects transmission, the reception is adapted automatically, based on the Pic header and its suffix: either none, p2, or p4.

I attach a short audio file that you can play back in FLdigi via File - Audio - Playback (select all files (*.*) and then the audio file), after setting fldigi to MFSK64 at 1500 Hz audio. If should decode 3 (greyscale) images in a row:

PM5544_283x227_MFSK64_Pic_Mode_Test_X1+X2+X4_2025-02-16.ogg <- This is the audio file to test the 3 speeds.
PM5544_283x227.png <- the original image (in color), which was sent as greyscale to have a shorter duration.
pic_2025-02-16_175606z_X1.png <- original speed [Note there's no suffix in the Pic header.]
pic_2025-02-16_175654z_X2.png <- double speed. [Please don't ask me why suffix 'p4' is used for double speed...]
pic_2025-02-16_175721z_X4.png <- quadruple speed. [-... and suffix 'p2' in this case, for quadruple speed. I just don't know.]

You see the degrading decoding quality, as the speed increases? Obviously, you could send a larger image with 4 x the area (WxH) in X4 mode during the same time as the original at standard speed, but then, the overall image quality will not be any better, just the size of the image appears visibly bigger. Note that I have quite intentionally heavily compressed this audio file, leading to an unusually small file and rather poor quality. But this way, it kind of behaves like a (stable and reasonably strong) HF path, giving an idea what a receiving station might see in each of the settings.


Your picture (showing very good reception actually!) doesn't look /skewed/ (or \the other way\), which would indicate a sound card speed calibration issue, but your otherwise straight image has partially shifted sideways, let's call it 'sliced'. This usually happens when the PC is busy doing other 'things' (blame it on multitasking or a bit of an overload of other programs drawing much CPU power) and FLdigi (or even your sound card) momentarily doesn't get the continuous CPU support it needs to convert the image without interruption. Any brief pause in the decoded bitstream (although it's analog via the radio, before the ADC conversion within the sound card) will cause an immediate side shift of the remainder of the image, and possibly a tiny lost portion. I have side-shifted back the respective parts in your screenshot and now it looks quite good. You'll find the original (full) decoded image with a date/time stamp in your data folder under fldigi.files \images. Check the location via Menu - File - Folders... - WEFAX images, and it may be called something like 'pic_2025-02-15_205141z.png'. The full path usually is 'C:\Users\<USER NAME>\fldigi.files\images', unless you have chosen a different location.


You can sometimes find a direct root cause for this image 'slicing' behavior, e.g. WSJT-X suddenly starting to decode something (FT8) in the 'background', or a scanner checking for undesirable files, when an e-mail arrives or a website opens, or the like, just to name a few processes that may draw a lot of system resources. If you have or suspect such an issue, try to stop this interfering process and have FLdigi run as the only 'demanding' application, if possible. You may also try to generally increase the FLdigi process priority, e.g. via the Windows Task Manager, Find 'fldigi' in the Applications list, right-click it and choose 'Go to the process'. In the Processes list, right click fldigi.exe, choose 'Define Priority' and set it to 'High' for example. This may (or may not) have a positive effect, provided it's a software decoding issue, rather than the sound card itself. In the Process Manager, in Processes view, you may also try to find other processes that demand a lot of CPU, if you klick the CPU column to have the list sorted accordingly.


On the other hand, if, during image reception, you mouse click around within FLdigi, e.g. changing the frequency offset, or even click onto the RX image preview, this may also cause such image reception disruptions.


I attach a couple of the views mentioned above as examples:


Re_winfldigi_Sending_Pics_2025-02-16_1631_inline0_A)_original_view.png

Re_winfldigi_Sending_Pics_2025-02-16_1631_inline0_B)_straight_view.png

Re_winfldigi_Sending_Pics_2025-02-16_1631_inline0_C)_straight_image.png

Re_winfldigi_Sending_Pics_2025-02-16_1631_inline0_D)_skewed_L.png

Re_winfldigi_Sending_Pics_2025-02-16_1631_inline0_E)_skewed_R.png


If actual skewing occurs, this is caused by a mismatch between the TX and the RX sound card calibration. An absolute reference can be found by calibrating the RX sound card setting using a precise Time Signal, e.g. WWV. It's described in the FLdigi Help file in the chapter 'WWV codec PPM measurement'.

I also attach my 'FLdigi_Soundcard_ppm_Calibration_Recipe_2024-12-10.zip' in case you need it for yourself or someone else sending /skewed/ images.


Hopefully this explains what has happened and what to try to improve the result.


73s from Bavaria

SWL Tobias
.-.-.
Am Sonntag, 16. Februar 2025 um 16:31:57 MEZ hat Randy Buxton, W4IFI via groups.io <randybuxton@...> Folgendes geschrieben:


[Edited Message Follows]

Thanks for the information Tobias.? Except when I transmit a picture in MKSF64 it indicates Cp4 when selecting x2 and Cp2 when selecting x4.?
?
Here's a picture I received from a local station on 40 meters during our test of sending pictures.? We were switching between x1, x2, and x4. Didn't make a difference.?
?
Why causes this picture to be skewed?
?
-Randy


Re: Rearrange macros #macos

 

make a copy, and edit the copy. if you srew it up, delete and make a new copy.
?


Re: Sending Pics

 
Edited

Thanks for the information Tobias.? Except when I transmit a picture in MKSF64 it indicates Cp4 when selecting x2 and Cp2 when selecting x4.?
?
Here's a picture I received from a local station on 40 meters during our test of sending pictures.? We were switching between x1, x2, and x4. Didn't make a difference.?
?
Why causes this picture to be skewed?
?
-Randy


Re: ICOM IC-756PRO III NO Cat with FLrig on Win11

 

GaDay All! I went back and installed previous versions of FLrig? 2.0.0 thru 2.0.03.
Those worked fine thru 2.0.03. So all is good in the world. Works just fine with the latest FLdigi build.
Dave W1HKJ, if you are reading this was not able to run the Event log on either 2.0.05 or 2.0.05.93.
It just would not provide any telemetry. Anyway it's working.?
?
? ? ? ? ? ? ? ? ? ? ? ? 73 de Steve KB6HOH


Re: Sending Pics

 

Hi Randy and all interested in this topic,

Below, you'll find my personal views, along with a few recommendations, on the MFSK image mode.

As you wrote, right-clicking in the TX pane and selecting 'Send image...' opens the respective dialog, allowing to load and transmit an image (usually a png, jpg or static gif image).


The special Button X1 is the 'TX speed multiplier' selector. It is described in the 'Fldigi Users Manual 4.2.00' as follows:

The "X1" button is a three-way toggle that allows you to transmit an image file in
X1 - normal and compatible with other modem programs
X2 - double speed, and
X4 - quadruple speed. X2 and X4 are fldigi specific image modes.

Note that the figure indicated on the button is not always in synch with the chosen mode, but the sequence always is 'X1 -> X2 -> X4 -> X1'. Also, the window caption shows the size of a loaded image, but the active speed multiplier setting is not included.

So better try it out before actually going on the air. The X1 standard speed produces a Pic Header such as 'Pic:240x160C;', double speed 'Pic:240x160Cp2;', and quadruple speed 'Pic:240x160Cp4;'. The 'C' is the tag for 'color mode' (omitted in greyscale), while the 'p' may just stand for 'picture' in this FLdigi definition, probably to avoid confusion with the 'x' (in W times H) used for the image dimensions.


- - - - - -


Why offer such different options in the first place?

Note that images are always transmitted per pixel in an analog way within the given MFSK bandwidth (lower frequencies represent darker, higher frequencies brighter colors), left to right, top - down, from the first to the last line at the very bottom. The advantage of analog image transmission is a (usually) shorter transmission time than for a digital transfer, and its tolerance against QRM. Tolerance meaning that noise will be visible as false-colored pixels or lines, but the entire image will not be lost, which usually is the case, if a digital image mode is interrupted in any way, or just too weak. The concept is somewhat similar to the well-known SSTV mode (older and not included in FLdigi), but it is not compatible.

Since the bandwidth and timing precision of an HF channel are limited, there is a reasonable maximum speed that can be realized before the pixels start to get blurred or even shift due to ionospheric effects like Doppler shift and multipath. The speeds chosen for MFSK images equal just about the physical limit, and may, in certain cases, already be a bit beyond, producing certain unintentional artefacts.

Note that transmitting an image takes quite a bit of time. This is defined by the formula (from the FLdigi Help file, with W and H being the number of pixels in width and height, respectively):

Time(sec) = W * H / 1000 for black and white

Time(sec) = W * H * 3 / 1000 for color

Color mode thus takes 3 times the B/W time, because each pixel is transmitted in a sequence of 3 color channels, red, green, and blue, which allow a very high number of colors to be represented, plus a brightness from black to white.


- - - - - -


In practical terms, consider a few things prior to transmitting.

Let's assume you have a nice image of the Moon you wish to send via MFSK. It is 800 x 1600 pixels, with the Moon roughly covering the central portion.
In your preferred graphics editor, first trim the image to only contain the Moon plus a bit of a dark 'frame' around it, whatever you visually prefer (there is no limit as to the W/H ratio, anything will work).

The dimension may now be something like 300x600. May look nice, but consider the TX time:

Time(sec) = W * H * 3 / 1000 for color means 300*600*3/1000 = 540 seconds, or nine (9) minutes! Is this really what you wish to (and can) put on the air?

Since the image content, the Moon, is almost perfectly black and white, you may wish to decide sending it in greyscale (Button 'Xmit Gry') instead, cutting the TX duration by 3, to 3 minutes.


Anyways, this may still appear a bit long, especially for a first try or a quick 'surprise' greeting. This is where scaling down a source image to a 'reasonable' size for transmission is the solution:

In your preferred graphics editor, scale the image down to 200x400 pixels for example, which cuts the greyscale TX duration down to 1.33 minutes, or 01:20, which appears to be a lot more appropriate for an MFSK image. You may try to (suitably) sharpen it before transmission, which may, yet to a lesser extent, enhance the impression of the received image.


On the other hand, if you agree upfront with your QSO partner to send a higher resolution image, taking into account the long TX duration, that's okay, as long as you're sure that your rig can handle an uninterrupted 100% power output of the given number of minutes without overheating. Unless you know for sure it will be OK, never aspire to use maximum PA power in digital modes. A rule of thumb calls for max. 20...30% of the peak power output, but, of course, this depends on the rig and its actual cooling situation.


The above example was specifically chosen to show the threefold TX speed advantage of a B/W or rather greyscale image. For color images, you may instead shrink the size a bit further to keep the overall TX time at bay. Generally speaking, it's a good practice to decide upfront which (part of an) image makes most sense to transmit, and try to avoid unnecessary 'borders' (which take up lots of extra time), thus literally focusing on the 'important' part of the view. Sometimes a suitable detail in higher resolution is more appealing than a full 'landscape' view.


- - - - - -


Back to the speed multiplier: You may say well, I'd rather use a higher resolution image and simply select a higher speed. Which is fair enough, as it actually cuts the above-mentioned TX duration by the respective factor, but there's no free lunch in physics (and thus the MFSK analog image transfer).

Speed factors above 'X1' will reduce the (visual) resolution accordingly, leading to more blur in the received images.

Also, due to the higher speed, ionospheric effects may show more distinctly, e.g. a light horizontal jitter (offset) between lines or double edges (echoes), usually caused by multipath and the resulting variations in the signal path and the travel time of the signal.

So in the end, if the image subject really needs size, you may opt using an X2 or X4 multiplier mode, but don't expect the result to be any clearer when received. Yet it may, admittedly, be more visible and impressive from a certain distance from the receiving screen, if that is something to factor in.


- - - - - -


Finally, you may ask, in which way the different MFSK modes differ in terms of image transmission.

Even more so, since the timing calculations described above are common for all image capable MFSK modes!

The very noticeable difference is in the resulting image resolution (clarity or sharpness) of the received image.

If you try to send an image in MFSK16, it will take just as long as in MFSK32 or MFSK64, but it will appear rather blurry.

MFSK32 will produce a visibly clearer result, and MFSK64 should look quite 'sharp' in comparison, but these modes will also use a respectively higher signal bandwidth.

The MFSK128 mode may not even fit into a ham bandwidth allocation, but it should theoretically be even clearer upon reception. On the other hand, any signal degradation may then (more quickly) lead to false-colored pixels, and thus the result, over an HF path, may not appear any better overall.


- - - - - -


If you want to get a good idea of what MFSK text and image transmissions are capable of, tuning in to Kim KD9XB's Shortwave Radiogram programs, which are broadcast on shortwave several times a week, and usually include text and images in MFSK32, MFSK64, or both. Info and schedules are found at 'http://swradiogram.net'.


- - - - - -


I hope this explains a bit of the background and practical usage of the MFSK image transmission.


Best regards and 73s

SWL Tobias
.-.-.
Am Sonntag, 16. Februar 2025 um 04:34:40 MEZ hat Randy Buxton, W4IFI via groups.io <randybuxton@...> Folgendes geschrieben:


I'm sending pictures in MFSK64. I load the picture, click x1, XmtClr. In the send window it reads: "200x254Cp4;"?
?
What is does "Cp4" indicate?
?
Thanks.
?
-Randy


Sending Pics

 

I'm sending pictures in MFSK64. I load the picture, click x1, XmtClr. In the send window it reads: "200x254Cp4;"?
?
What is does "Cp4" indicate?
?
Thanks.
?
-Randy


Re: XEIGO G90 SETTINGS? #fldigi

 

I use “ NoMachine”. Which is free and I have used for several years to manage both my Win7 & Linux pcs remotely. www.nomachine.com

73
Dave
N4CVX


Re: XEIGO G90 SETTINGS? #fldigi

 

Any one know how to use Any Desk or Team Viewer to look at my settings for PSK in my computer?
Thanks
--
73's de NU4N