** This announcement may be forwarded to anyone interested in getting on the ARRL Maryland-DC (MDC) Section Winlink message distribution list and participation in MDC Digital emergency communications (EMCOMM) training activities. Interested parties should send a Winlink message request to MDCWINLINK-1 and they will be added to the distribution list. The information that you will need to participate in monthly Check-ins and Challenges will be sent out via Winlink messages. Challenge Announcements will be sent approximately 2 weeks before the Challenge. **
** If VarAC or Fldigi is your mainstay and you wish not to use Winlink, please send your commercial email address to bill.n3xl@verizon.net and you will be added to the distribution list. The commercial email option is not open for Winlink users.
PURPOSE:
This exercise requires the use of photo resizing tools that are built into the Winlink (Task 1), VarAC (Task 2), and Fldigi (Task 3) programs. You will learn how to make adjustments to images, as necessary to achieve reasonable transmission times. Task 3, Fldigi messaging, is incorporated for interoperability with ARES groups that use the ARRL Narrow Band Emergency Messaging System (NBEMS). This exercise is also designed to familiarize you with Climate.gov, Science & Information for a Climate-smart Nation, https://www.climate.gov/.
PLANNING:
Find the wildland-urban interface (WUI) wild fire image at https://www.climate.gov/news-features/feed/fires-along-wildland-urban-interface-rise/. Right-click and save the image to a convenient folder.
File size limitations to achieve reasonable RF transmission times will vary, depending on the quality of your connection, propagation conditions, and equipment limitations. The nominal file size limit for Winlink and VarAC is 100 Kbytes, which is generally too large for RF transmissions. We are suggesting that you resize your images below 50 Kbytes for Vara FM and 15 Kbytes for HF. Make adjustments as necessary, if the transmission fails or takes too long.
You are encouraged to send images to as many Target Stations as possible. The HF and VHF Target Station lists will be provided to everyone on the MDC Winlink distribution list on 3 June 2025. Carefully observe the modes, frequencies, dates, and times of operation provided. VarAC users should make use of PSKReporter and Winlink Position Reports to identify active Target Stations.
Winlink Packet P2P and Vara FM P2P users should consider the use of digipeating to extend their range beyond VHF line-of-sight. A VARA license is required to digipeat using Vara FM.
Ensure that your VARA, VarAC, Fldigi, and Winlink software programs are up-to-date.
VARA - https://downloads.winlink.org/
VarAC - https://www.varac-hamradio.com
Winlink Express - https://downloads.winlink.org/User%20Programs/
Fldigi - https://sourceforge.net/projects/fldigi/files/
Incident: MDC EMCOMM CHALLENGE
Subject: IMAGE XFER - RELAY TO N3XL
Date/Time: 5 JUN 2025, 00:00 ET to 8 JUN 2025, 23:59 ET.
GMT Offset: -4 Hr.
EXECUTION:
TASK 1: Winlink Image transfer:
a. Find the wild fire JPEG image and download. https://www.climate.gov/news-features/feed/fires-along-wildland-urban-interface-rise/
b. The Winlink image 'Resizing Tool' will be used. Suggested procedures: Create 'Message' > 'New Message' > select Attachments > 'Add' your selected image > 'Edit/Resize-Image' > 'Change Size' > make your changes > 'Save > 'Save Changes' > 'Finished' > Address and post to your Outbox. Send your messages via Target Stations for relay, or directly to N3XL.
c. When relaying to N3XL via a Target Station, place IMAGE XFER - RELAY TO N3XL in the Subject line. (Well defined subject lines are needed to achieve meaningful Winlink 309 message logs. Develop good habits now.)
TASK2: VarAC Image transfer:
a. Find appropriate wild fire JPEG image and download. https://www.climate.gov/news-features/feed/fires-along-wildland-urban-interface-rise/
b. If desired, set up an outgoing files directory in the QSO tab of your Settings, C:\VarAC\Outgoing_Files is suggested.
c. The VarAC 'Image Shrinker' tool will be used. Suggested procedures: go to 'Tools > Image Shrinker > LOAD IMAGE' > resize the image using the 'Resolution' and 'Quality' sliders > check the 'My callsign' box > SAVE TO DISK. The file will be saved to your Outgoing files directory by default.
d. Once connected to your Target Station, use the SEND FILE button, select the file from the Outgoing files directory, or elsewhere.
e. If relaying via a Target Station, type RELAY TO N3XL in the New message window at the bottom of the main window to inform the Target Station and then SEND.
TASK 3: Fldigi HF (mode MFSK32) Image transfer:
a. Review the image transfer training at https://drive.google.com/file/d/11WT6GyQkOqavS0-ejTaqqcBO4KkEoJOG/view?usp=sharing/.
b. Establish a connection with your Target Station, see ESTABLISHING FLDIGI CONNECTIONS below.
c. In blue transmit area of the screen, right click and select Send Image Press the "Load" button in the dialog window and select wild fire JPEG image for transmit. The file selection dialog has a preview capability so you will see what the image looks like. If the transmission fails using X1, be prepared to resize the image using the X2 or X4 buttons in the dialog window. This will shrink the image size at the receiving end.
d. Send your picture via a Target Station for relay, or directly to N3XL. After sending, secure the Tx/Rx function or the Rx button.
e. If relaying via a Target Station, type RELAY TO N3XL in the SEND window, before or after sending the image.
* ESTABLISHING FLDIGI CONNECTIONS (P = Participant. TS = Target Station)
P - Tune radio to TS dial frequency. Use QSY button to adjust frequency to the 1500 sweet spot.
TS - QST QST de WX3F WX3F, QST QST de WX3F WX3F K (call periodically, QST=calling all stations).
P - Precisely align cursor to TS signal, to obtain good copy. The display center frequency will normally be at, or near, 1500.
P - Once good copy of the Target Station is established, respond WX3F WX3F de KB3XYZ KB3XYZ, I HAVE IMAGE FOR RELAY TO N3XL K.
TS - RR KB3XYZ good copy, pls send your picture K.
P Send image. Terminate the transmission when image xfer is completed.
TS Brief acknowledgement, or request to resend, etc.
CHALLENGE CREDIT:
N3XL will provide message acknowledgements to participants for images that have been successfully delivered. Participants are encouraged to complete all three tasks in the June Challenge, but do what you can. You are encouraged to use as many modes and Target Stations as you can. Participation will be documented in the MDC Digital EMCOMM Challenge Report and in the ARRL MDC Section News, https://arrl-mdc.org/section-news/.
HIT A HOMERUN: Everyone completing all 3 tasks will be recognized for hitting a homerun.
NOTES:
* A VarAC alert_tags.conf file will be sent with the Target Station Lists. Copy and paste this file into your VarAC program directory to receive MDC Bulletins and Target Station alerts.
* Tip Sheets on Winlink, VarAC, and Brevity in Emergency Communications are available on Google Drive: https://drive.google.com/drive/folders/1qU3Yj9wuxuxIRzHk9MVRqQZbiptVqADA?usp=sharing
* Challenges are conducted on the Thursday through Sunday preceding the second Tuesday of each month, except in October which is reserved for ARRL SET activities. (The second Tuesdays are MDC Digital Check-ins.)
* If you have any ideas for the content of future Challenges, or suggestions for improvements, let me know.
73 and GL in the Challenge,
Bill N3XL, MDCWINLINK-1
Learn by doing.