NBEMS-Local

Step 2.3: Transmitting an flmsg message

In Step 2.3 of this course, you will get experience transmitting digital files with flmsg. You will be making simulated transmissions using the TX Generate technique that you learned in Step 1.3 of this course. Your simulated transmissions will be saved as audio files, which you can then replay.

This step assumes that you have already installed and configured flmsg. If you have not done both, see Step 2.1: Download, install, and configure flmsg.

Requirements (for all exercises in Step 2.3)

Exercise 2.3.1

In this exercise, you will simulate a transmission of a paragraph of text with flmsg. Though it won't go out over the air, it's time to bring your good ham radio practices into fldigi. As with ham radio voice, you will end your fldigi transmission with your call sign. If you have no call sign, use "XXXXXX" in these exercises.

Exercise configuration: Before beginning this exercise, follow the steps outlined on the Off-the-air exercise preparation page for configuring fldigi. (Using this link will open the page in a separate browser window or tab.)

Confirm that fldigi is set to transmit in the MFSK32 operating mode.

In this exercise, you will not record your transmission for later playback. (That comes next.)

Launch flmsg if it is not already running. Use Form|Blank to open the "Blank" form. (See NBEMS menus and configuration for help with the "W|X" and "Y~Z" method of describing software menus and configuration.) If the Blank form contains text, use File|New to clear it.

Follow these instructions:

Alice was beginning to get very tired of sitting by her sister on the bank,
and of having nothing to do. Once or twice she had peeped into the book
her sister was reading, but it had no pictures or conversations in it, "and
what is the use of a book," thought Alice, "without pictures or
conversations?"

You are ready to transmit this simple flmsg form as a file with fldigi. Look at (don't touch) the flmsg menu item "AutoSend". Surprise! It's not a menu item at all -- it's a button! OK, now click "AutoSend". At this point, if you did not save your file with File|Save, you will be offered another chance to save your file. Otherwise, fldigi will go into action and send your transmission.

The first thing you should notice is fldigi is now set to MFSK128 and is transmitting in that mode. Lesson: When using flmsg's AutoSend to transmit a file, it is the operating mode set in flmsg, not the mode set in fldigi, that determines the mode fldigi will use.

You will also see fldigi transmitting your form. Unlike raw text pasted into fldigi's transmit pane, flmsg file content is transmitted with "markup": header lines at the beginning and tags enclosed in angle brackets ("<>") that indicate components of the form. These will be interpreted by fldigi on the recipient's side.

fldigi will handle the transmission automatically, including the return from transmit to receive at the end.

Sent files

flmsg prompted you to save your file before you sent it. Here's how you might use a sent file for something else:

Exercise 2.3.2

In this exercise, you will mostly repeat what you have done in the previous exercise. However, this time you will use a different fldigi form. You will also save an audio copy of your transmission.

Exercise configuration: Before beginning this exercise, follow the steps outlined on the Off-the-air exercise preparation page for configuring fldigi. (Using this link will open the page in a separate browser window or tab.)

Confirm that fldigi is set to transmit in the MFSK32 operating mode.

Launch flmsg if it is not already running. Use Form|Plaintext to open the "Plaintext" form. If the Plaintext form contains text, use File|New to clear it.

Follow these instructions:

Alice was beginning to get very tired of sitting by her sister on the bank,
and of having nothing to do. Once or twice she had peeped into the book
her sister was reading, but it had no pictures or conversations in it, "and
what is the use of a book," thought Alice, "without pictures or
conversations?"

Now you will create an audio recording of your transmission and save it as a file. Unlike your "Sent" file in flmsg, which is text in an flmsg format, this fldigi file is an audio .wav file and contains the sound that the sender transmits and (ideally) that the receiver receives over the air. In fldigi, use File|Audio|TX generate and check the checkbox. fldigi will ask you to name your output file and decide where to put it. You will need this file again, in Step 2.4, so remember where you've put it! Here, I suggest placing your file in your workspace folder (and I suggested you create that folder in C:\\Users\your-account\ and that you name it "fldigi.learn"), but you can put it anywhere you like. You'll be creating many output files, so I suggest you name them in a way that helps you remember what they are. Here, in Exercise 2.3.2, I suggest naming your file "ex2.3.2a.wav". (If you decide to create more than one output file in any exercise, you can change the letter to the left of the dot from a to b, c, etc.)

Now, in flmsg, click "AutoSend". At this point, if you did not save your file with File|Save, you will be offered another chance to save your file. Otherwise, fldigi will go into action and send your transmission.

fldigi will handle the transmission automatically, including the return from transmit to receive at the end. Now use File|Audio|TX generate and UNcheck the checkbox.

If you wish, you can use "File|Audio|Playback" and check the checkbox. Locate and select the file you just created and press the Open button. [If you don't see that file in the dialog box, you may need to get around a small bug in the Windows version of fldigi: click in the box above the Open and Cancel buttons and select "All Files (*.*)"; it should now appear.] You will probably want to answer the question "playback continous loop?" with "No". The specified file will then begin playing. Un-check the box at "File|Audio|Playback" to stop playback, or allow it to continue playing to the end of the file. flmsg will display the file as you specified on fldigi's "NBEMS interface" configuration page. If flmsg was not running, it will open if you have configured it to do so on that page.

Exercise 2.3.3

In this exercise, you will mostly repeat what you have done in the previous exercise, but with a different fldigi form.

Exercise configuration: Before beginning this exercise, follow the steps outlined on the Off-the-air exercise preparation page for configuring fldigi. (Using this link will open the page in a separate browser window or tab.)

Launch flmsg if it is not already running. Use Form|ICS|ICS213 to open the "ICS-213" form. If the ICS-213 form contains text, use File|New to clear it.

Follow these instructions:

Item, Quantity
Atorvastatin Calcium 40mg, 20
Paromomycin Sulfate 20mg, 20
Metronidazole 250mg, 20

Thank you.

Alice

Create an audio recording of your transmission and save it as a file. In fldigi, use File|Audio|TX generate and check the checkbox. fldigi will ask you to name your output file and decide where to put it. You will need this file again, in Step 2.4, so remember where you've put it! Here, I suggest placing your file in your workspace folder (and I suggested you create that folder in C:\\Users\your-account\ and that you name it "fldigi.learn"), but you can put it anywhere you like. You'll be creating many output files, so I suggest you name them in a way that helps you remember what they are. Here, in Exercise 2.3.3, I suggest naming your file "ex2.3.3a.wav". (If you decide to create more than one output file in any exercise, you can change the letter to the left of the dot from a to b, c, etc.)

Now, in flmsg, click "AutoSend". At this point, if you did not save your file with File|Save, you will be offered another chance to save your file. Otherwise, fldigi will go into action and send your transmission.

fldigi will handle the transmission automatically, including the return from transmit to receive at the end. Now use File|Audio|TX generate and UNcheck the checkbox.

Exercise 2.3.4

In this exercise you will transmit one more fldigi form.

Exercise configuration: Before beginning this exercise, follow the steps outlined on the Off-the-air exercise preparation page for configuring fldigi. (Using this link will open the page in a separate browser window or tab.)

Launch flmsg if it is not already running. Use Form|Radiogram to open the "Radiogram" form. If the Radiogram form contains text, use File|New to clear it.

Follow these instructions:

SEND 25 COUNT HUMULIN R U-500 KWIKPENS FROM PHARMACY TO RESPONSE CENTRAL X MUST ARRIVE BY 7 PM

Create an audio recording of your transmission and save it as a file. In fldigi, use File|Audio|TX generate and check the checkbox. fldigi will ask you to name your output file and decide where to put it. Here, I suggest placing your file in your workspace folder (and I suggested you create that folder in C:\\Users\your-account\ and that you name it "fldigi.learn"), but you can put it anywhere you like. You'll be creating many output files, so I suggest you name them in a way that helps you remember what they are. Here, in Exercise 2.3.4, I suggest naming your file "ex2.3.4a.wav". (If you decide to create more than one output file in any exercise, you can change the letter to the left of the dot from a to b, c, etc.)

Now, in flmsg, click "AutoSend". At this point, if you did not save your file with File|Save, you will be offered another chance to save your file. Otherwise, fldigi will go into action and send your transmission.

fldigi will handle the transmission automatically, including the return from transmit to receive at the end. Now use File|Audio|TX generate and UNcheck the checkbox.

On the Air

If you are a licensed Amateur, have a transceiver, and can interface it with your fldigi and flmsg installations, and you are in contact with someone who can receive flmsg files from you, you may wish to try transmitting files with flmsg over the air. Ask your contact to listen for you. Please remember to identify your transmissions with your Amateur Radio call sign as required by FCC regulation.

Summary

In the Step 2.3 exercises above, you simulated transmitting flmsg digital files with fldigi.

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John Rabold KS6M
April 2020