WELCOM TO ARES® TRAINING Class Participation Some information here may be basic to some of you but totally unknown by others in the class. For the purpose of this class we will assume you know very little about operating digital modes. We want class participation. Ask questions when they come to your mind. If you know something I don’t then share it with the class. We can all learn together. This is not a sink or swim class. If you need to know how to swim you should be told the basics before getting into the water. Here are the basics of the digital modes and NBEMS. So bear with us as we tell you the basics and at the end of the presentation we will get into the water. Today’s Topics What do we need to know to run a digital sound card mode? How to connect the computer and sound card to the radio. How to set up the sound card levels. What software to use. How to configure the software for the mode. What mode to use and under what conditions. How to get the message into the software to send it, Including editing the text message or image to a proper size and format that can be sent. How to receive a message and format it for presentation to the person the message was intended for. Established Digital Modes by Georgia ARES Section. Georgia ARES has three established and recommended digital modes of operation at the present time, a fourth may be added soon: Georgia ARES website now has a new digital page outlining the these modes at http://gaares.org/digital The Three Ga. ARES Digital Operational Modes: NBEMS … a Sound Card Mode using FLDIGI / FLMSG *Main subject for today’s class and demonstration. *Can send messages and files to someone even when the other party is not at their station. *Many modes within NBEMS to use depending on propagation and band. PSK MT63 Olivia WL2K (Email over Radio) *Can be used with TNC or a sound card mode /RMS Express /winmore software. *Peer to Peer (simplex) or over WL2K Network. D-STAR / D-RATS *Can be used via the internet or peer to peer simplex. *Can send regular text or ICS forms and attachments. *Can send and pull files from someone else’s computer when the other party is not at their station. *No external sound card interface, everything handled internal in the radio with one single cable from radio to the computer. *Can set-up reflectors accessed via RF or the internet including private message screens. Why do we need Digital Modes and what can we do with it? Sending data and binary files (Text and Images) Sending long Lists of information Lists of medications / patients Information needs to be error Free (Error Correction) Can be sent on separate frequency from voice net When attachments need to be sent Can send to any email address (WL2K) Low cost Hardware or no hardware in some cases Can relay digital messages without a computer or interface using a cheap digital recorder. Try Sending this by Voice !!!!! What other digital modes would you think we as Amateur Radio EmComm Operators might use. Slow Scan TV (SSTV) EasyPal and Windrm *Digital SSTV? *EasyPal and Windrm: Not really SSTV, the SSTV part has stuck because they send images. In basic terms it's file transfer also known as DRM "digital Radio Mondiale" The advantage over analogue SSTV is the error correction. With error correction you can get a perfect image IE what is sent is what you receive. Two such programs are EasyPal and Windrm and will use the same basic interface that you may already be using for analogue SSTV. Why might we need these image modes such as EasyPal, SSTV or Windrm? Damage assessment images. Image of actual hand written prescription needs to be sent. The message was given to you in image form to send. NBEMS Narrow Band Emergency Messaging System. WHAT IS IT? NBEMS is a system made up of software programs working together seamlessly to send and receive digital data using a sound card mode. What are these software programs? FLDIGI / Sound Card Modem Program/ this is the work horse of the NBEMS software suit. FLMSG / Message Handling Program/ This is the Message interface of the NBEMS software suit. FLWRAP/ Error Correction verification program (Needed on rare occasions) NBEMS / FLDIGI DEMO How do we connect up to make all this work? Hard Connection vs Acoustic Coupling Hard connection includes a physical Sound Card interface connected between the Radio and a computer. (Example: Signalink USB) Soft connection (Acoustic Coupling) would be simply placing your radio speaker/mike next to your computer speaker/mike to receive and send the digital sound. Acoustic Coupling works best on FM and using MT63-2000 Mode. This is not the ideal way but does work when no interface is available and the message must go out. What Sound Card Modes to use? Olivia 8/500 for HF (good for week and noisy signals but slow). MT63-2k for VHF (fast and reliable on FM simplex or through repeaters. PSK-125 HF or VHF not as reliable with noisy signal but faster on HF than Olivia. How do we get the information that we need to send into the software to send it? Type it directly into the modem software (FLDIGI) and send. Type it into the message / forms software (FLMSG) and send. Send it as an attachment in FLMSG that can be handled by the software such as an Excel CSV file. Send an image file as an attachment in FLMSG or as a binary image file in the appropriate software such as EasyPal or Windrm or even SSTV. What is the limit of the file size that can be sent. Depends of the software and mode you are using to send it. Depends if it is binary or text. Using NBEMS and generally speaking try to keep data/ text file sizes under 6k in size if possible. Binary files (images) 4k or smaller if possible. If sending images, using software specifically designed to send binary (image) files you can send an image of up to 30k reasonably fast. (EasyPal or Windrm) NBEMS Sending Time by Mode Benchmarks Discussion Compression and PSK don't play well together! For 2K file, compressed file takes longer to transfer with PSK modes. 6K file transfer is not appreciably faster with PSK Reason is varicode Varicode is optimized for “normal” text Example – “e” = 11, “q” = 110111111 Compressed data no longer has normal distribution of characters Compression Conclusion At first glance, compression sounded like a good idea but... Doesn't work well with PSK Can't compress a small file very much Potential to lose entire transmission if single bit is dropped Conclusion: Compression not worth the trouble most of the time What if the image file is too large to send? Use image editing software to reduce the size of the image file. HOW Save file in smaller format ex: save BMP or GIF to JPG. Decrease color depth or change to B&W if color is not absolutely needed. Crop unneeded margins in image. Reduce actual size of image, it can be blown back up if needed on the receiving end. Example of good free software to do this is Irfanview. http://www.irfanview.com/ Example of how to reduce the size of an image file in Irfanview. What if the text file is too large to send? Break the file up into two or three separate transmissions. The receiving station can paste them back together. Send them in a faster mode if propagation and signal reception permits. Convert .doc and highly formatted files to .rtf or .txt files. Compress files over 6k in size if using MT63-2k or a mode that likes compression (not PSK). Communicate with your served agency as to what you can do and what you will need from them to send their messages. The served agency needs to know how to get the message to you and in what form. How will you as the operator get digital files from the served agency to send. How will you present a received message to the served agency? Is a printer available for you to network to? Do you need to give them the message on a usb drive for them to print? Do you have your own printer? Do you have internal email access to send and receive messages from the served agency? Sit down before hand and work out these details with your served agency. Don’t wait until the incident and find out you have no way to share sent and received messages. Considerations that will mean failure not to mention embarrassment. Did you practice, practice, practice using digital modes. (Use it or loose it) Don’t wait on others to train you. Practice at home. If you are sending through a repeater, is the time-out on the repeater set to allow maximum duty cycle. Digital Data messages are longer than average voice messages. Tones on repeaters should be turned off during drills and emergencies. Do you know the lowest power level you can use to send a data message to your net control or other stations from your assigned location. Is all the software you need loaded and ready to go on your computer and do you know how to use it. Including text and image editing software. (Excel, Adobe Reader, FLDIGI, FLMSG, FLWRAP, Irfanview and a text editor of your choice) These should all be part of your GO-Kit and on your check list. Are your basic computer skills where they need to be? If not, learn them or take some classes. No need to be a computer Guru, just the basics. Pierce County ARES Training Site: http://www.piercecountyares.org/nbems Don’t forget to Calibrate your sound card. Your soundcard’s clock rate needs to be checked and adjusted in the modem software (FLDIGI) if necessary to calibrate the clock rate to the sampling rate. (if you don’t understand this, never mind, just use CheckSR software to find the number you need to inter into FLDIGI. This is a one time calibration as long as you are using the same sound card. Download CheckSR software and follow instructions. http://www.pa-sitrep.com/checksr/CheckSR.exe We will demonstrate when we set-up FLDIGI. Setting up the NBEMS Suit Configure FLDIGI First. FLDIGI FLMSG FLWRAP Configure FLMSG. Configure FLWRAP DEMONSTRATE NBEMS SOFTWARE CONFIGURATION AND USE. Demonstrate messages being sent via acoustic coupling.