This blog supports the Educational Radio Net, an amateur radio net that takes place Wednesdays at 8:00PM on the 2 meter repeater of the Puget Sound Repeater Group, 146.96MHz -600, with a tone of 103.5, located on Queen Anne Hill in Seattle.
The purpose of this net is to help our fellow amateur radio operators learn theory, gain practical knowledge, and generally benefit from the experience of the more seasoned operators.
Your hosts are Bob Helling, K9PQ, and Lee Bond, N7KC.
Thursday, July 9, 2009
Blog Post 6 – MMSSTV—Slow Scan Television software by Makoto Mori, JA3HHT – Introduction to analog image transmission
Wednesday July 15, 2009
This is Curt Black, WR5J with the Educational Radio Net – No digital QST tonight so we can get everyone set up and running with MMSSTV.
Slow Scan TV (SSTV) is a way to get the high-information density of visual images shoe-horned into the audio-bandwidth typically used by the human voice of about 2.5kHz. Bandwidth for full motion NTSC video requires about 4.5Mhz or 9.0 if you use both sidebands as you transmit– so minimally a bandwidth ratio of about 2000/1. .
On slow-scan TV we do this by sending just a single image and spreading that single image out in time. It typically takes from 8 seconds (Robot Grey-scale 160x120) to 269 seconds (ScottieDX RGB 320x256) to transmit an image. And you probably noticed that those images are way smaller than the 525 lines of an NTSC video. It seems like a lot of fuss, but images are powerful things, capable of communicating easily more than the typically cited, “1000 words” of meaning. Like the one at the top of this blog post of the Seattle Library from a recent Simulated Earthquake response for Seattle ACS. .
Just like the RS-ID being implemented by our digital modes, SSTV uses a standard burst at the beginning of the transmission called VID to allow the software to decode using the correct format. The details of that signal are appended to the end of the Yahoo Group MMSSTV Setup and Use compilation. . Just like an NTSC TV picture, the SSTV signal is built line by line and point by point. In contrast to the digital pictures we will do next week with EASYPAL, the information is built by capturing the audio information and correlating a particular brightness with a particular audio frequency. To start each line, a sync pulse is sent at 1200 Hz. There is one of these per line, so you should be able to see a peak at 1200 Hz in the energy in the spectrum display. The brightness information is sent between 1500 and 2300Hz. As the picture is being transmitted, you will see clearly this band of frequencies being received. . To tune in the station on HF-USB, just adjust your main tuning dial to place the sync pulse at 1200. MMSSTV and all the other programs provide markers at 1200, 1500 and 2300Hz. to make this easy. .
To use this software, just go to the SSTV watering holes such as 14.230 or 14.233. This is the best know and possibly the best defended frequency in all of amateur radio. I enjoy listening during contests as someone innocently goes in to call CQ. .
One weakness with this software is its identification of different sound cards. The more you have the harder it is to find it because there are only numbers – no names. You just have to try one number after the other until you are receiving. .
For the receive side of this software, you would typically leave the AUTO box checked, but if you don’t start to receive the signal automatically, you can try SCOTTIE 1 or 2 – the most often used modes in North America. If you are receiving DX from Europe or Japan, try MARTIN 1 or 2. Most operators give a voice ID at the beginning of their transmission where they announce the mode being used, although that can be lost in the noise if the stations aren’t strong. You can definitely decode and see adequately signals from stations too weak to allow copy of a voice signal. .
To learn more about this mode or ask questions about the software, check out the Yahoo Group http://groups.yahoo.com/group/MM-SSTV/ .
To check out activity on the bands or see what has been transmitted recently, check out http://www.g0hwc.com/ G0HWC has sites for Analog and Digital SSTV and links to the software as well as helpful discussion. .
Onward to getting the software setup: OK, This part isn't working since I can't get the images in the right place - please go to the http://groups.yahoo.com/group/wa-digital/files/ area and snag the Blog Post #6 and see what this was supposed to look like... vy sri. .
1. Download MMSSTV from http://mmhamsoft.amateur-radio.ca/mmsstv/ .
2. Install MMSSTV, and work through these instructions. Add your callsign when prompted. .
3. Shut down all other programs you might have running, then start MMSSTV and select the OPTIONS pull down from the top tool bar. .
4. Select SETUP MMSSTV(0) from the pull down .
5. This will bring up a three tabbed window, select the RX Tab. .
6. Set up the RX Page as follows, (DO NOT CHANGE THE LEVEL CONVERTER INFO): .
7. Set up the TX Page as follows, (DO NOT CHANGE THE TxBPF/TxLPF, TUNE BUTTON INFO, or PORT value): .
8. Set up the MISC page as follows, (DO NOT CHANGE THE FIFO, or DEVICE ID):
9. Note above: DO NOT change anything in the CLOCK window yet. 10. Once you have these items set up calibrate the software to your clock setting by the following procedure: ======== Clock calibration ========
In SSTV, errors in the timing of the clock appear as a slanted image. For MMSSTV, you are not required to have the absolute and exact clock frequency value (e.g. 11025Hz). But it is important to get MMSSTV informed of the discrepancy of your soundcard to a standard. .
In normal situations, you would only have to adjust the slant by using the Sync window. If you want to calibrate your soundcard very accurately, listen to a standard radio such as WWV, CHU or JJY. .
1) Go Option, Setup, Misc page, and push Adj button. 2) Receive standard radio signal (e.g., WWV and JJY). 3) Tune into the tick sound. 4) Continue listening to the sound for a while. You have a vertical line. 5) Click the upper point of the line. 6) Click the lower point of the line. (these instructions actually show up in the calibration window) .
An alternate method is to locate a station that believes they are calibrated correctly. They become the "Standard" for you and all who come after you. Clearly the problem with this is it can become a “blind leading the blind” situation with errors propagating through the community. Cleary if you are willing to do the calibration above you will have done your part to make the world a better place. .
11. However, for the non-WWV technique, have the “standard” station send a picture to you. After that picture is complete move to step 12. .
12. Select the "SYNC" tab, (you can do this while the picture is being received), then select the NICONICO (Happyface), button ONLY after the picture is complete. A number will appear in a small white box in the upper part of the screen. This is your error from the selected "Master" station. .
13. You may press the "MEM" button. This will lock your computer to the "Master" stations clock frequency. Your receive is now setup. .
Operation:
First you need to get some images to work with. Luckily nothing could be simpler. In MMSSTV, click on the RX tab toward the top of the screen and the S.pic tab at one third up from the bottom. There is room for some 300 photos in this Stock Pictures area. .
Open a Windows Explorer/File Manager window and open the folder where you have some images. Select an image and drag it onto the icon on the taskbar for MMSSTV until MMSSTV opens, then continue dragging to one of the open frames along the bottom of the screen. Drag in as many as you find interesting and which you might want to share. Colorful, active photos are best, but standard images of rigs and operators are fine, too. .
Set up your Com Port – check your Port assignments by getting to where you can see MY Computer – right click and select Properties –on the window that opens, click the Device Manager tab in the middle of the window. From the list that appears, click on the Ports (COM and LPT) icon and look through the resulting list of ports for the one assigned to your radio PTT. It is certainly possible to brute force try one after another if you can’t get it another way.
. That could be it – click the TUNE button and adjust the transmitter for 50% or less of your full power rating for the radio you are using (SSTV is 100% duty cycle – pretty much key down for 90 seconds or more - far more than your voice requires of the equipment – don’t toast your radio. .
For more details of the mode, check out the SSTV- MMSSTV-How-To-Set-Up-Doc on the Yahoo Group site for WA-DIGITAL. It starts out with duplicate info as this blog, but then goes into more specifics on the mode and operating.
Next week we will contrast tonight’s work with MMSSTV and analog image transfer with EASYPAL – digital image (and much more) transmission. EasyPal is an amazing program. The software is on the WA-DIGITAL site as will be a setup document really soon. Please download it and install it before next week’s session.
This is Curt Black, WR5J with the Educational Radio Net – Please stand by for a DominoEX 22 Digital QST
(As before please set up your FLDIGI software. (Menu OP MODE, then select DominoEX, then slide over and down to select DominoEX 22 - since we haven’t tried that mode yet. Recall you can right click on the mode box at the bottom left corner to open the configuration screen for the modem. Do that and confirm that filtering and FEC are both checked – the 1.0 filter bandwidth factor is fine)
DominoEX is supposed to be quite robust and moderately fast and it has the advantage of transmitting tactical data during any pauses in the transmission – watch the bottom of the screen in the block to the left of the AFC and SQL check boxes. Just a reminder from last week - don’t have your volume very loud – place your microphone fairly close to your speaker so you don’t confuse the modem with echoes of the audio.
If none of this sounds familiar, go to the blog and look at post #2.
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OK off we go.
Send File Ghandi – DominoEX 22
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Last week we got some practice with RS-ID, the Reed-Soloman Identifer, to automatically switch our software to the correct mode and frequency. It sounded like we were getting about 40% of folks automatically switched by the end of the Net. After the net, I went up with Tammy to practice a little more on the West Seattle repeater and we tried turning on the video ID as well. That sends a short block of Hellschriber encoded text that paints the waterfall with your call, the mode and submode, or some tactical information if you wish.
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It seemed to work better, possibly because the video ID is sent first and maybe the repeater is already pumping out my audio by the time the RS-ID is transmitted. You set all that up on the ID tab under the Configure menu. Right now please make sure your “Detector searches entire passband” check box is checked.
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I’ll send a file now with BPSK-250, but I’ll send a short file first, then a longer file. That should give folks a chance to tune into the signal if the software doesn’t do it for you. I’ll transmit RS-ID each time so there should be three chances for the software to switch you automatically before the long file. Please be sure your RSID button is checked and showing green in the upper right corner of the FLDIGI screen.
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Send File K3UK…
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WSPR – Weak Signal Propagation Reporter
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Joe Taylor, K1JT, of Princeton has written a series of programs for brilliantly combining digital Signal Processing (DSP) and ham radio to allow us to plumb the depths of weak signal work.Prior to the development of his tools, moon bounce with a modest station or bouncing short signals off the ionized trails of passing meteors was beyond the realm of possibility.The program's name is WSPR (pronounced "whisper", which seems appropriate for extremely weak signals)
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The name of the digital protocol implemented in WSPR is MEPT_JT, where the letters stand for "Manned Experimental Propagation Tests, by K1JT".
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1. Download WSPR from the WSJT home page,
http://physics.princeton.edu/pulsar/K1JT/
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2. Run the resulting executable file to install WSPR. .
3. Start the program by double-clicking on its desktop icon. .
4. Open the Setup -> Options menu and enter your callsign and
6-character grid locator.
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5. Enter the COM port number to be used for PTT control in the box labeled
PTT Port.(For example, enter 1 if you will use COM1.)Enter 0
if you will use VOX control.
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6. If you have more than one sound card and do not wish to use the
Windows default sound card for WSPR, examine the list of sound
devices in the console window (the one with black background).
Enter the desired device numbers in the boxes labeled Audio In and
Audio Out.
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7. Select your transmitter power in dBm in the appropriate Options box.
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8. On the main screen, enter your SSB transceiver dial frequency and
desired Tx frequency in MHz.Your transceiver should be set to USB
mode.(You can also set the Tx frequency by double-clicking with
the mouse on the waterfall display, after setting the Dial
frequency.)
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9. Click on "Rx" to receive only, on "Tx" to transmit only, or on the
desired average percentage of transmission cycles.In this case
the program will decide whether to transmit or receive during any
given two-minute interval, and will do so in such a way as to
randomize your T/R pattern.This procedure will maximize your
chances of receiving any other WSPR station operating within a +/-
100 Hz range centered 1500 Hz above your dial frequency.
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10. Be sure that your computer clock is correct to +/- 1 second.If
necessary you can make small adjustments by left- or right-clicking
on the "Dsec" label.
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11. WSPR will begin a Tx or Rx sequence at the start of each even UTC
minute.The waterfall will update near the end of each Rx
sequence.
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12. Check the box "Upload spots" if your computer is connected to the
internet and you want your received spots uploaded to the WSPRnet
database.For information on this excellent resource, direct your
browser to www.wsprnet.org.
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13.The weirdest thing about this software is setting the frequency – just use the drop down box under the BAND menu item.Check the WSPRNET.ORG website at the bottom of each page for the current QRGs or frequency list.If you need to update your software, just type the value into the box on screen and it will update the value in program.
Here are the configuration screens – to find the value for the AUDIO in and AUDIO Out boxes see the next screen...
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Just take the AUDIO DEVICE number from the screen above.If you are running a NAVIGATOR interface or a SIGNALINK, you will see USB AUDIO CODEC as your choices – just pick the one that is both an input channel and USB AUDIO CODEC for the input.
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Set your transceiver on one of the frequencies from the website.Then click somewhere to the left of the 100 to 300 frequency scale to set a transmit frequency. As you monitor a frequency, you will see activity as colored horizontal bands in a particular 2-minute time slot.Each slot gets a rectangle on the screen.If you transmit, there will bebright green line and you will notice the time stamp on the bottom of the rectangle will miss a 2 minute period.
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All the stations are synchronized – your computer clock should be within a second of WWV.Use a piece of software like Dimension 4, free for non-commercial use from
This is a weak signal mode – it really doesn’t need much power – try 1 watt and see who hears you and where they are.Try to operate at your local sunrise or sunset to really see what happens as the bands change – that grayline propagation thing really is real – it is when I’ve gotten the farthest.
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The MEPT protocol is a variation of work done by IK0VVE and others which they called QRSS for very slow cw.
While the software is cool and works great, the aspect that has lead to the significant popularity of WSPR is the website where you can see where your signals are going in real time – or have a record of where every signal you produced was ever heard.That is WSPRNET.ORG
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This Week’s Digital News…
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FLDIGI, the software we have been using the last 5 weeks has been updated to version 3.11.6. No changes that would keep you from doing what we are doing tonight, but changes to the contest logging and other logging functions to automate grabbing the correct info into the correct fields. Also changes to the PSK Reporter functions.
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Ham Radio Deluxe version 5 is now available. The new version has RSID, Contestia mode and lots more including:
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a.. DX Cluster,
b.. Sunspot (Solar Cycle) displays,
c.. Audio recorder and monitor ,
d.. Greyline display,
e.. Support for Microsoft Access, MySQL and Microsoft SQL Server,
f.. Full networking.
a.. Enhanced Digital Master 780:
a.. User interface simplified,
b.. Added Contestia and RTTYM.
a.. Satellite Tracking is now a standalone program:
a.. Improved display.
a.. Rotator support is now a standalone program:
a.. Point and shoot,
b.. DDE tracking,
c.. DDE interface,
d.. Modern display.
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From Seatcp mailing list (If you haven't yet met the SEATCP list - you will when we get to Packet and other resources the are "...digital and fun"...
Get HRD/DM780 here, or if you don’t like to install things on the bleeding edge, you can wait until next week at this time when an update/bug fix is promised. This is still listed as beta. It is scheduled for official release on October 1, 2009..
There are many enhancements – RS-ID being a primary one. It has RS-ID implemented in a very nice way. When an RS-ID is detected in the audio passband, a window opens and asks you if you would like to switch to Blah-mode on Blah-frequency. A single click takes you there.
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Just a reminder – we have been messing with FLDIGI because it is a very elegant package that is fully featured but simple to setup and use. HRD is not so simple, but is a great package and when used with DM780 is very fully featured. Your experience with FLDIGI should serve as a great foundation for HRD if you choose to try it out. As an indication, HRD is a 55meg download. FLDIGI is 6.6megs. Just for equal time, MULTIPSK for version 4.14 is 7.9megs. I can not put any of these on the Yahoo site because it has a maximum file size of about 5 megs.
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So, three main digital packages now have RS-ID. Here are the links for each one:
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FLDIGI by David Freese, W1HKJ and Skip Teller, KH6TY:
Patrick’s package is a great technical achievement. He offers the most sensitive modems and detection routines available and many modes (such as ALE-400) that are not available in any other software. The challenge is his user interface is very dense and can be tough on a first-time user. His philosophy is he wants all the controls in one place – and they are.
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Other packages of significance don’t yet have RS-ID, but may be of interest to you, including:
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WINWARBLER, part of the DXLAB suite and available here:
Next week: Slow Scan TV – Image transmission using both analog and digital software.
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Sign up for the Yahoo group at http://groups.yahoo.com/group/wa-digital for past blog posts and the files. New files this week include a sample of about 5 minutes of 20 meters during the last field day from the ACS station. Feel free to practice with the playback function in FLDIGI. Instructions are on the file description on the Yahoo site.
This is Curt Black, WR5J with the Educational Radio Net – Please stand by for a PSK-31 Digital QST
(As before please set up your FLDIGI software for Menu OP MODE, then select PSK then slide over to select BPSK-31 – for binary phase shift keying – 31baud.Just a reminder from last week- don’t have your volume very loud – place your microphone fairly close to your speaker so you don’t confuse the modem with echoes of the audio..
If none of this sounds familiar, go to the blog and look at post #2.OK off we go.
That was a little chunk of field day to remind you what fun that was.There were more digital signals than ever before on the bands.How did folks do on the copy?
We have about 10 weeks to go till September 2, so I think I’ll change the format just a bit skip the check-in process so as to recover that 10 minutes I took last week.Although I appreciated the chance to get some feedback from folks on how their installations have gone, maybe we can make it less formal and just grab questions as they come up.
I’m beginning to have faith that there are people out there in radio land.Just a reminder, there are now 20 people signed up on the YAHOO! WA-DIGITAL list – that is turning into a good resource for the software and instructions and background documents for this series.Please signup if you haven’t yet.Just this week I put up background documents on PSK-31, RTTY, WSPR and a proposedschedule for the rest of the summer.As always, please feel free to break in with any questions at any time during the net.Also, don’t hesitate to send an email during the week at black@nwfirst.com.
This week I’d like to go over a few more features of FLDIGI.I’d like to get setup for automatic switching to the proper mode using the Reed-Solomon Identifier or RS-ID feature.I’d also like to get us to the point where we can send each other error free messages using the WRAP utility included in the NBEMS suite.
Review from Last Week
Several useful features are included in FLDIGI for changing quickly “on the fly”.For example, you can right-click on the macro buttons to edit their content or to cut or paste information.Remember, there are 4 sets accessable from by clicking on the right end of the menu bar.As we discussed on the net, you can left-click on the mode name in the far lower left corner of the screen to switch to other variants of the mode currently selected.A right click of the same button brings up the configuration pane for the mode currently in use.
There are just a few features that are not configurable, “on the fly”.During the net I was asked how to customize the height of the waterfall.I had trouble finding it which seemed odd because I’ve rooted around quite a bit in the program.After the net I found it under the Configure Menu /UI(User Interface) choice / then click on the “Restart” tab.This is a strange name and I would say it is why I couldn’t find it during the net, but it is called that because changes made here don’t occur until the next restart of the program.
Under the Restart tab you can set how high the waterfall is in pixels and how wide the waterfall is in Hertz.I usually use the max height of 160 and 3500 for the width.You can always zoom in with the X1, X2 or X4 in the bar under the waterfall, using the left facing arrow next to that magnification control to slew the waterfall to the left and the right facing control to move it to the right. The double bar that looks like a pause button is for centering the currently selected location where the modem is focusedin the waterfall (all these only work when you are zoomed in enough to need them).
We talked about the 2 minute buffer that is constantly saving the audio and how you can change modems in the OP MODE menu, and then click over an interesting signal with the right mouse button and then left click to decode the last 2 minutes with that new modem.
Last time we talked a little about the makeup of a PSK-31 signal and how sensitive the mode is during transmission to avoid over driving and splattering.We looked at the information in the bottom line of the screen next to the mode identifier.While decoding PSK-31, those boxes contain information on the Signal to Noise ratio and Inter-Modulation Distortion (IMD).Remember to make those measurements on an idling PSK-31 station and that we are working to keep the value below minus 24 dB (for example minus 34 dB would b a great signal – a minus 11 dB would be a nasty signal that would be attracting lots of attention on the band). These values are only for received signals – so you need the help of your fellow hams to find the quality of your own transmitted signal.There are at least two devices to help you monitor your own signal as it is being transmitted – the IMD Meter by KK7UQ, Clint Hurd and the PSK Meter by George Rothbart, KF6VSG.A comparison of the two products is on the bottom of the page found at http://kk7uq.com/html/imdmeter.html
The Wrap Utility
The WRAP utility program checksum feature lets sending stations transmit a plain text message, an image or a binary file with embedded coding that includes a checksum calculation. Multiple receiving stations can then verify 100% copy on received text.I thought we would try that now.I’m running version 3.11.5 but all versions in the 3.11 series work for this.
Before we get to wrapping, I want to say, “YOU SHOULD NEVER WRAP any of the MICROSOFT OFFICE APPLICATION FILES WITHOUT CONVERTING THEM”You should convert a word document to text, an excel spreadsheet to a Comma Separated Value (CSV) format text file, etc.A Word Document with 1 character in it is 13.8 kilobytes, when zipped it drops to 1.8K, but it is still a ratio of nearly 2 thousand to 1.The WRAPing process expands the file to half again its original size during the ASCII Base64 encoding so that 1 character word file is still nearly 3 k.Send text whenever possible.This is a training issue, we are communicators trying to help transmit information – not a specific file, but the information in that file.Think about efficiency before you hit the TX button.
To set up for automated receipt of a “WRAPPED” message, please go to the CONFIGURE menu and slide down to the MISC item.On the window that opens click on the TEXT CAPTURE tab.Click the check box next to, “Enable Detection and Extraction”.
This will cause any text that begins with the string, or series of characters between, “[WRAP:beg] and [WRAP:end] to be pulled out and saved in your WRAP folder inside your FLDIGI.FILES folder under your login name in DOCUMENTS and SETTINGS.This is very WINDOWS centric, but there are similar settings for Linux and Apple OS users.If you navigate to that folder, I would suggest putting a shortcut to it on your start menu.Then you can quickly open it and look for files saved there.I would also put a copy of NOTEPAD and the WRAP.exe file in there – then everything is in one place and you have a shortcut to it on your start menu.
You should now be ready to receive a wrapped file – so lets try that now – Questions?
To send a WRAP file, just create a text file by saving from your favorite word processor or pasting text into NOTEPAD.Then save the file into the WRAP folder as a text file.Take that text file and drag it over the icon for the WRAP.EXE utility and a new file will be created in the same directory with the same name except with a.WRAP extension.To send this file, drag the new file to the bottom of the screen over the FLDIGI task and wait for that window to open, then continue dragging until you are anyplace in the send window, most of the bottom half of the screen.Release the mouse button and the wrapped text will appear in the window to be sent.You may want to put some explanatory text in the window before the file, but when you are ready, just press the TX button on the macro line and off it will go.
The powerful thing about this is that it allows transfer of files from one station to many in a format that allows all stations to know they have received the file error free.Previously we would have to use an ARQ (Automatic Repeat reQuest) linking protocol one station at a time.This has great potential for digital nets like this one or those that follow.The NBEMS suite has an application called FLARQ.exe.It allows two stations in QSO to form a linked condition and send error free data back and forth – however it is only one station at a time.Since we can’t demo it through a repeater, and it only works on one station at a time, just check out the documentation on the PA-SITREP website or the author’s website at http://www.w1hkj.com/FlarqHelpFiles/flarq.html
Since that was pretty dense and a radio net is clearly not the best format for such a hands-on lesson, the blog post and Yahoo group file for Post #4 has links to two files on UTIPU which show exactly the steps I’ve described here, but much more graphically.
The "RS" ("RS" for "Reed-Solomon") identifier allows automatic identification any digital transmission done in one of the RX/TX modes handled by FLDIGI. If the sending station is using the feature (currently available in MULTIPSK, FLDIGI and by this August, HRD/DM780 – probably someday in MixW).It detects the mode used and the center frequencywith a precision of +/- 2.7 Hz.
As soon as this identifier is received, FLDIGI switches to the proper mode and frequency and immediately decodes the QSO in progress or the call (CQ). This identifier is transmitted in 1.4 sec and has a bandwidth of 172 Hz. It is usually detected down to a Signal to Noise ratio of -18 dB(or perfectly at about -16 dB), so it has a sensitivity equal or better than the majority of the digital modes (RTTY, PSK31...).
This identifier can be transmitted before each CQ call or prior to each answer in a QSO.Turn on this feature by going to the CONFIGURE menu and selecting the ID item.On the window that opens, check both the, “TRANSMIT MODE RSID” box and the “Detector Searches Entire Passband” check box.The actual searching is somewhat processor intensive, so to turn on the function in receive mode, there is a control in the upper right corner of the screen next to the TUNE button labeled, “RSID”.Go ahead and make those settings.Questions ?.
Now that you are set up, keep your mode setting on BPSK-31 and we will give it a little test.I’ll pick a new mode and a new frequency.Make sure your RSID button is pressed in the upper right corner of the FLDIGI screen.We’ll see if everyone switches over and starts to decode it.
RTTY (Radio Teletype)
The second most popular digital mode.Somewhat more complex to set up and much less spectrally efficient than PSK-31.I think the designer of PSK-31 was hoping his new mode would replace RTTY, but for better or worse, it is wildly popular all around the world and, while somewhat brute-force, is a lot of fun to use.It can be hard to know what frequency to spot either yourself or others.Unlike almost all the other digital modes we will use, this one can be found in Lower Side Band.That is from tradition – and gets more confusing as we try to figure out how to spot our own frequency.We need to pay attention to which sideband we transmit on in SSB.So once we get back to HF and away from these demonstrations in FM, the sideband and frequency will rear their ugly heads as issues.On RTTY, the inverted signal matters in contrast to PSK-31 or the other PSK flavors.
Rather than get too bogged down at this stage of our hour together, please look to the following websites for guidance:
Next Week one of Joe Taylor’s modes, K1JT, called WSPR, “Whisper” – the Weak Signal Propagation Reporter”.An amazing mode that takes about 300hz of HF bandwidth and lets people all over the world share it to test RF propagation.Your individual transmission will only be about 3 Hz wide.It has been tremendously enhanced by the presence of the website, http://wsprnet.org/ where after you easily create a free account, you can look at worldwide activity and a database with 7 million spots and growing at about 1000 spots an hour, 24 hours a day.I’ve already put the software on the Yahoo group and the blog post with more info should be up early this weekend.
Session 3 - Continuing a Summer of Digital Communications Fun June 24, 2009
This is Curt Black, WR5J with the Educational Radio Net – Please stand by for a DIGITAL QST
Send File ALLMODE.wav
CHECKINS
Tonight I want to practice more with FLDIGI and work our way through more on-screen controls as we continue to acoustically couple our radios to our computers.
So, before the net please set up your laptop near your radio with a microphone plugged into the computer so that the sound in your shack shows up visually on the waterfall display on the FLDIGI software. Set it up so if you clap your hands you see an indication of that sound moving down the screen.
If this is your first session - go back to the previous blog entries (just lower down on this page) and read about downloading and installing the free software in the Narrow Band Emergency Messaging System (NBEMS) suite. It would be great if you could get your sound card calibrated with the CheckSR.exe software before the net to make sure your copy is as good as possible. If you can't you will still have good copy with MT63, but some of the other modes may not be as forgiving.
PSK-31 - Phase Shift Keying (at 31 baud and with two tones 31 Hz apart).
As the most popular digital mode on HF, I thought I would be remiss if we didn't start with PSK-31. I want to emphasize that we will be moving on to lots of other modes, so if your eyes are rolling back in your head because this is too pedestrian, have faith, we will be getting to the really cool stuff like WSPR, WSJT and SSTV real soon now. But this week - an intro to the PSK Modes.
I have put some great PDF files of PowerPoint presentations up on the wa-digital group site at
http://groups.yahoo.com/group/wa-digital/files/
Please join this Yahoo group - it seems the best way for me to get some of these great visual resources into your hands quickly.
The two files by Clint Hurd, KK7UQ are from his Anchorage Convention talk last summer in Alaska. Clint lives in Port Orchard and has made interfaces and tools for helping people get the most out of digital modes for many years. Start with the file Alaska Basic Slides.pdf and check out all his information on digital modes. For the adventurous check out the second file, Alaska Advanced Slides.pdf for great tips on adjusting the waterfall for maximum sensitivity and resistance to strong signals in the audio passband. Much more great information is available directly from Clint at his website:
http://kk7uq.com/html/hamfest.htm
Here are some hints for working with PSK31 or any of the PSK flavors.
Hints to New PSK Users
1. Make sure you are putting out a pure signal. Don't overdrive the rig (make sure ALC is showing absolutely no sign of life) You cannot achieve better communications by over driving the audio on any of the digital modes that require linearity. These include all of the modes that have an amplitude modulation component. Some like PSK and THROB have both an amplitude and a frequency or phase modulation component. An overdriven signal may produce more decoder errors than a properly driven signal of lesser power. This is particularly true for all variants of PSK
2. The best way to know what your signal is like is to ask on the bands for a report from others – the software of the person receiving your signal will report out what your intermodulation distortion 3rd order intercept is in decibels (IMD) – you want an IMD value below minus 24dB. You don't need a slide rule to figure this value out - the software calculates it anytime there is an idling PSK-31 station being decoded. It also gives you the signal to noise ratio - you need to pay attention to that before you believe the value you are seeing for the IMD window. If you have a nice -34dB IMD you are transmitting one fine signal. At minus 18 people will probably start giving you unsolicited reports since your signal will be about twice as wide as necessary. At –11dB you will have much of the band after you. For more good news - since we are using FM for these examples, the overdriving part is greatly reduced. But it is extremely important for your HF future as an A-1 Operator.
3. Don't type in all caps. This slows down your transmission, makes it more prone to errors, and is just annoying.
4. Remember that your HF rig is not set up to operate at a 100% duty cycle – voice operations tax your finals much less than most data modes. Lower your power to a level of 50% of what your rig can produce so you don’t burn out your finals. This will help the bands as well since many of our digital modes are detectable at very low power levels. Particularly for the weak signal modes like WSJT – one loud signal in the passband of your radio can make everyone else, especially DX, sadly unreadable. Chances are you will produce good copy at the stations listening to you with just a few watts. That is particularly true when we get to JT65A on 14.076 USB...
5. There is way more to digital operation than PSK31. Tune a little above the PSK activity and call with Hell or MFSK16 or Olivia 16/500. You can use the sked page to arrange experiments with new or more esoteric modes. Try these pages for scheduling some activity –
http://www.obriensweb.com/sked/
http://www.hamspots.net/
These websites aren’t needed for PSK31 – it is nearly always available on the frequencies listed below. But the less common modes are more challenging to find folks for a QSO. Below is a table of common PSK31 frequencies – you will frequently see the wider signals of PSK63 just a little higher.
We also have permission to practice on the West Seattle repeater at 441.800 output (up 5 MHz for input)with a tone of 141.3. Just ID with voice before and after your digital transmissions and maybe yield to any voice traffic that wants the repeater... It has been pretty quiet lately. Hopefully that will change as we bring the West Seattle Amature Radio Club back to life...
The yahoo group is another great way to set up a schedule with your fellow Educational Radio Net folk. Just send your message to wa-digital@yahoogroups.com
As we send PSK-31 back and forth tonight - you will probably notice that you can lose copy if the volume gets very loud. The phase shifts that the software is looking for can be really messed up by echos in your shack- particularly from a wall about 16 feet away. The software is looking for phase shifts every 32 milliseconds - sound travels about 1000 feet per second - so that wall 16 feet away is just right to produce an echo at a really bad time - actually all the sound bouncing around your shack is the bad part of acoustic coupling. For PSK-31 just try turning the sound down and getting the mic closer to the speaker on the radio to avoid echos.
I guess, this brings us to the desirability of having an interface between your radio and the computer.
There are some great advantages to acoustic coupling - for one it couldn't be simpler. Additionally, there is no problem with RF getting into the computer when you are transmitting - at least not from the interface cables. But some of the modes we will want to use are going to be increasingly choosy about phase and the timing of sound arriving for processing.
There are lots of choices of interfaces from junk-box parts to the $99 Tigertronics SignaLink to the $360 US Interface Navigator - each has pros and cons.
There is lots of satisfaction from doing things out of the junk box. You can build a very workable interface with jacks and wires. You can build a better interface with isolation transformers. You can build a great interface with optoisolators and at some point, the time begins to make some of the commercial products look pretty good. The more expensive units provide lots of control over the radio, actual FSK keying (as opposed to audio-frequency shift keying, AFSK)and great user interfaces with just the controls you need where you might want them.
We will continue to do an acoustically coupled transmission each week for practice and will probably try a round-robin through the repeater in another week or so. However, eventually I suspect you will want to have an interface to get signals into and out of your computer in the best possible form. So, please consider if your time and financial resources will allow it - it can open up an amazing world.
Please take a look at Clint Hurd's presentations from the Alaska Hamfest last August on the Yahoo Group wa-digital if you haven't already.
I'm having trouble adding images to the files in this blog.
To get around this, I'd like to invite people to join a Yahoo group I started about a month ago. This group is intended to facilitate communication among Washington State ham radio operators interested in experimentation and utilization of digital communication modes over radio. The software will primarily include NBEMS (Narrow-Band Emergency Messaging System) software and other packages for reliable digital communications on the ham bands (Multipsk, Ham Radio Deluxe (HRD)).
The group will be moderated and can be found at:
http://groups.yahoo.com/group/wa-digital/
TO JOIN Send an email to black@nwfirst.com with your request and I'll send back an email with the invitation.
The group is modeled after the Pennsylvania group at: http://www.pa-sitrep.com/NBEMS/index.html
Please start with their site to download the NBEMS software, get the MACROS and other supporting files and installation instructions. Good job Pennsylvania!
For radio operators in the Seattle Area, we plan to have weekly nets to test and practice with specific modes on both HF and VHF/UHF. For the Summer of 2009 we are meeting on the PSRG Repeater, 146.96 output with a -600khz shift and an access tone of 103.5hz. The net is at 8:00pm on Wednesday evenings. Please check the blog posts at http://www.educationalradionet.blogspot.com/ for the preparation prior to each week's net. Usually, you will need to download some software or configure your station in a particular way to decode the transmissions for the evening.
The first motivation for joining would be the diagrams that are included with the step by step instructions for downloading the software are in the Files section of the group. They are the same as the ones on the PA-sitrep site. As soon as I'm able, I'll get the files up there for the software as well as the documentation.
I look forward to seeing you on the waterfall!
C. W. Black - WR5J West Seattle, Washington black at nwfirst dot com
QST de WR5J – For the Educational Radio Net – Curt in Seattle
Here is the second post of the Summer Digital Series for Seattle hams interested in trying out some digital modes over the next several weeks of the coming summer.
This post is intended to provide step by step instructions for the download and setup of the FLDIGI software as part of the NBEMS suite.For questions contact Curt at black@nwfirst.com and put SUMMER DIGITAL somewhere in the subject line,
Thanks es vy 73 de WR5J
Introduction:
The purpose of this file is to help Elmer those interested in NBEMS/FLDIGI to develop standardized procedures and settings for the use of the software.
The material in this file was only slightly modified from the information on the Pennsylvania SitRep ARES group website for Western Pennsylvania.A big “Thank You to this group for doing the heavy lifting of assembling and organizing the information.Their original information can be found at http://www.pa-sitrep.com/NBEMS/index.html
The use of the NBEMS software requires nothing more than a laptop or desktop computer and an amateur radio transceiver (even an HT) to send and receive data/text using the NBEMS soundcard-based digital software.
This site concentrates on only a few of the primary digital communications modes available within the FLDIGI software package that are best suited to Emergency Communications.
A key to promoting the widespread adoption of digital communications is to keep the protocols as simple as possible and providing means of conducting digital communications with the use of equipment and transceivers that are already commonly used.
The NBEMS/FLDIGI software is the perfect package for digital emergency communications because it is:
-FREE!
- Easy to configure
- Easy to use
- Easy to modify and standardize
- Works on Windows XP, Windows Vista, Apple and Linux systems
- Usable without the need for additional/complex/expensive hardware
Step 1, Get the Software:
Here is the link to the NBEMS/FLDIGI Software Download:
- "win" is for windows XP
- "winV" is for windows Vista
When you click on the link for the appropriate download, you should be prompted to either "Open" or "Save" the program. Select "Save".
Click "Next" which lets you select the directory where you want to save the program on your computer. Select the directory for desktop or another directory (make sure you note which directory you save in) then click save.I usually select a download directory so I can archive these files as downloaded.This way, even if the internet is unavailable, I can access the files, possibly move them to a thumbdrive, and easily set up a new installation with the software.Similarly, in the sprit of preparedness, I like to store the files unzipped in a sub-directory, named, “extracted” to avoid any problems with that step. That way you can be certain you have the files and versions you want.
An alternate site for download of the software and its help file is http://www.w1hkj.com/Downloads.htmlThis site may have updated versions a little ahead of the PA-SitRep group and may be worth checking from time to time.It is also the direct source for the Linux and Apple (OS X) versions of the software.
Step 2:Installation
FIRST! - Be sure you have only one copy of cygwin1.dll (the one that came in your zipped file) on your computer.
WindowsXP users:
- Single right click on the "Start" button on the bottom left corner of your desktop.
- Arrow up and single left click "Explore". This opens your entire computer file directory.
- Single right click on your computer's root directory ( usually Local Disc (C:) )
- Arrow down and single left click on "Search".
- In the "All or part of the file name" search box, type cygwin1.dll then click "Search".
- After the search is complete, single right click on the instances of cygwin1.dll (with the exception of the one in your FLDIGI file folder) then arrow down and left click delete. Repeat this for each instance of this file with the exception of the one in your FLDIGI file folder.
Vista users:
- Single right click on the "Start" button on the bottom left corner of your desktop.
- Arrow up and single left click "Explore". This opens your entire computer file directory.
- Single left click on your computer's root directory ( usually Local Disc (C:) )
- In the "search" box in the upper right hand corner of the window, type cygwin1.dll
- Single right click on the instances of cygwin1.dll (with the exception of the one in your FLDIGI file folder) then arrow down and left click delete. Repeat this for each instance of this file with the exception of the one in your FLDIGI file folder.
Now you are ready to install FLDIGI.
Go to the desktop (or the directory where you saved the NBEMS/FLDIGI download file) and double click the FLDIGI file icon.
This will open up the file folder, which is in a compressed .zip format.
If running WindowsXP:
- Click "file" at the top right side of the current window, then click "Extract All". This opens an extraction wizard.
- Click "Next", then click "Browse" and select the directory where you would like the NBEMS/FLDIGI file folder to reside then click "Next". The window should now say that the files were extracted properly.
- Make sure the box marked "Show Extracted Files" is checked, then click "Finish".
- Double click on the FLDIGI folder icon.
- Now single right click on fldigi.exe, arrow down and single left click on "Create Shortcut". A new file will appear in the folder that says "Shortcut to fldigi.exe".
- Single right click on that folder, arrow down and single left click on "Cut".
- Close all open windows, then single right click on your desktop, arrow down and single left click on "paste".
- You should now have a shortcut icon to FLDIGI on your desktop.
If running Vista:
- Single left click "Extract all files" from the selections along the top of the current window, then click "Extract All".
- Single left click "Browse" and select the directory where you would like the NBEMS/FLDIGI file folder to reside. Make sure the box marked "Show Extracted Files" is checked, then click "Extract".
- Double click on the FLDIGI folder icon.
- Now single right click on fldigi.exe, arrow down and single left click on "Create Shortcut". A new file will appear in the folder that says "Shortcut to fldigi.exe".
- Single right click on that folder, arrow down and single left click on "Cut".
- Close all open windows, then single right click on your desktop, arrow down and single left click on "paste".
- You should now have a shortcut icon to FLDIGI on your desktop.
Step 3, Configuration and Setup:
Double click your FLDIGI desktop icon. If you have any errors or the program closes, please see the first item in Step 2, above about the cygwin1.dll file
1) Click Configure, arrow down to defaults, arrow over and click Operator. Then enter the appropriate information, click Save Config, then click close.The specific layout of the windows has changed since the figures shown below for FLDIGI 3.03, but the general approach to setup is the same.
2) Click Configure, arrow down to defaults, arrow over and click Waterfall. Click the left arrow on the low cutoff box until the figure is at 50. Click Save Config, then close.
3) Click Configure, arrow down to defaults, arrow over and click Video. Uncheck small font, video text - type "MT631K-L", video width - 4, check View Xmit Signal, then click Save Config and close.
4) Click Configure, arrow down to defaults, arrow over and click Sound Card. Select the appropriate sound card for capture and playback under port audio for the sound card that you will be transmitting with. Click Save Config, then close.
In Seattle we are starting with acoustic coupling of our radios and computers.For this reason, we will want to set up with the “capture” through the microphone input of the internal soundcard on your computer.“Playback” will be through the speakers by selecting the internal soundcard of your computer.This is different from what is shown below for what we will do later if we install a hardware interface between the computer and the radio.
5) Click Configure, arrow down to defaults, arrow over and click Misc. Check Transmit RSID and Wide Search Detector. Make sure Slow CPU is unchecked unless you are operating on a very slow computer.
6) On the main screen of FLDIGI, go to the bottom of the screen and set the first waterfall figure to -20, the second figure to 70, and the x setting to x1. Uncheck the sql box on the right bottom of the fldigi window.
Adding the Standardized WPA NBEMS Macro Set
1) Go to http://www.pa-sitrep.com/NBEMS/fldigi_macro.htm
2) Right click on the link to the macro, arrow down to "Save Target As" and left click.
3) You should now see your windows file directory. You will need to click on your profile directory (this will be the name that appears when you start your windows login). Double click on your windows profile name in the directory.
4) When you make it to the proper directory, you should see an existing file named "macros". This is the file you will be replacing.
5) Left click the save button. A window should come up saying that the file already exists and will ask if you want to replace/overwrite. Click yes.
Here is the current WPA Standardized NBEMS/FLDIGI Macro (25-Oct-2008):
Right click on the link above, then click "Save Target As", then place the file in the following directory:
WindowsXP users save to:
c:\Documents and Settings\urlogin\fldigi.files
Vista users save to:
Desktop\urlogin\fldigi.files
Replace "urlogin" with your login name when you start your computer.
When prompted with the message that this file already exists, select the appropriate option to overwrite or replace the existing file.
The primary macro set is indicated with the number 1 in the furthest right button. This is the primary set used during transmit and receive sessions.
The number 2 macro set is used for changing to different modes.
The number 3 macro set is for the use of MT63 1k Long transmit and receive sessions.
Here is a screen shot of the 3 macro sets:
To change from one macro set to another while running FLDIGI just click on the number to the far right of the macro line – it will change to 2, then 3 then back to 1 with each mouse click
Step 4, Sound Card Calibration
1) Download and save CheckSR.exe to your desktop. This is a small, standalone, application that consist of a single exe file. When you double click on it, once it's saved to your desktop, it provides the capability of analyzing your sound card offsets and gives you the corrections in parts per million (ppm):
2) Open NBEMS/FLDIGI, go to configure, defaults, sound card, audio devices tab and make sure you have the sound card you use for your interface properly selected from the capture and playback drop down choices. For Seattle folk, that will be your internal sound card.Later, if you choose to move to interfaces like the Signalink or Navigator, with their own sound cards inside, we will recalibrate to those external devices.Next click the audio settings tab.
3) Under the audio settings tab, you should see a sample rate drop down box for capture and playback. Under each drop down box, select the sample rate that has (native) listed after it and take note of this figure. Click save config, then click save. Close FLDIGI.
4) Going back to CheckSR, open the application (if it's not already open, double click on the desktop icon now) and from the drop down boxes for sound card settings, Input and Output, choose the sound card you are using with FLDIGI. Next, select the sample rate from the drop down box in CheckSR for the sample rate that FLDIGI showed as "Native" then click start.
5) Let the application run for about 15-20 minutes. You will notice that the numbers will progressively stabilize. After about 15-20 minutes, click stop then write down the resulting figures on input and output for the measurements in Hz and PPM. Keep this record – I keep a little table for each of the hardware interfaces I have as well as each internal soundcard – makes configuring for any laptop, desktop or interface easier… While it might seem counter intuitive, running the application for more than an hour or so seems to produce less accurate values – I don’t know if some internal register or something begins to overflow, but it starts to move to unrealistic numbers with more time.
6) Open FLDIGI, go to configure, defaults, sound card and click on the audio settings tab. Enter the PPM figures for RX ppm (CheckSR ppm Input figure) and TX ppm (CheckSR ppm Output figure). If you had a figure that resulted in a minus from CheckSR, enter the PPM setting with the minus symbol followed directly by the figure with no space. Then click save config, then close.
Although this procedure does not seem to be necessary for MT63 2k long on FM, it is advisable that anyone using FLDIGI, regardless of modes used, should perform this procedure immediately following setup. Once these calibrations are applied to the software, no changes should ever have to be made again, unless you change your software to radio interface sound card.
Step 5First QSO with FLDIGI on BPSK-31
These instructions are assuming that you are using a properly configured sound card interface. Keep in mind that if you do not have a sound card interface, you can plug a simple microphone into your sound card mic jack to monitor received audio from your transceiver speaker, but you will not have automated push to talk in order to transmit.
Double click your FLDIGI desktop icon. If you have any errors or the program closes, please see the first step on the installation page
1) Adjust your TX and RX window sizes by arrowing over the divider between the upper window (received text) and the lower window (transmit text). Left click and hold, then drag the divider up or down. Typically it is better to have the RX (upper window) using about 75% of the overall screen.
2) Go to Op Mode at the top of the screen and left click, arrow down to PSK then arrow over to BPSK-31 and left click. This sets you in PSK-31, the most common digital mode you'll find on the HF bands.
3) Tune your transceiver to a common PSK31 frequency:
Daytime: 14.070 MHz/USB, 10.140 MHz/USB, 7.070 MHz/USB
Evenings/Night: 3.580 MHz/USB, 7.070 MHz/USB, 10.140 MHz/USB
4) As is the case for all digital comms with FLDIGI, make sure all DSP including compression and noise blanker are turned off on your transceiver.
5) Arrow over a PSK signal in the waterfall and left click on the signal. You should now see the receive text being decoded in the upper RX window. If you see no text, make sure the squelch box at the bottom right hand corner of the program is unchecked.
6) Wait for a station to call CQ. On the received text, arrow over the first character on the Call Sign in the CQ and RIGHT click. This brings up a window that will let you insert the text that you right clicked on into the log. Arrow to Call and left click. You will notice that the call sign has now been inserted into the log.You are now ready to respond to the calling station.
7) Left click on the 2nd macro in the 1 set that is labled "ANS CALL/CQ" or hit F2 on your keyboard. You should now be transmiting and you should see that the station call you added in the log is now being sent along with your call sign. At the end of your response, assuming you are using a sound card interface, the rig should automatically go back into receive. At any time if your rig does not return to receive mode, you can pres the esc button on your keyboard to manually abort transmission.
8) If your system is configured properly and band conditions are sufficient, the CQ calling station should respond. Typical first exchange is name, location and signal report.
9) As you receive the calling station's name and location, you can right click on the given text and insert the information into the log, just as you did in step 6 to insert the call sign into the log. If the location is city and state (two words), highlight both words by left clicking and holding then drag over the desired text, then unclick. You will see that the text is now highlighted and you can right click to insert to the appropriate section of the log.
10) To respond with your first information exchange, click on the "exchange" macro or hit F3 on your keyboard. Now you can manually type your information or click the station info macro.
11) IT IS IMPORTANT TO NOTE that the exchange and station information macros will not automatically end your transmission, so you will want to click the BTU (Back to you) macro or hit F4 on your keyboard.
The symbols displayed on the macro buttons indicate how the macro will function:
Indicates auto transmit and auto receive
Indicates auto start (you will need to use BTU or manually switch to receive)
Indicates auto receive
Step 6 – Try Different Modes – Olivia
We will be focusing on 3 primary digital communications modes:
MT63 - Olivia - DominoEX
Each mode has it's advantages and disadvantages and the WPA-SitRep group recommendations are based on extensive field testing under varying situations and conditions.
MT63 2k Long - Local FM Comms
For local portable, mobile and fixed station operations on 2m and 70cm FM (repeater or simplex), MT63 2K long is our primary mode for detailed situation reports and database transmission and has been chosen for the following reasons:
- Can be used very effectively without a sound card interface (audio coupling)
- Extremely effective under poor RF conditions
- Extremely accurate decoding (major duplication of data and forward error corrected)
- Very forgiving on sound card tuning and calibration when used on FM
- Excellent for sending larger situation reports or databases
MT63 1k Long - Regional/Local HF Comms
For regional and local portable, mobile and fixed station operations on HF USB under moderate to good condition, MT63 1K long is our primary mode for detailed situation reports and database transmissions and has been chosen for the following reasons:
-Very effective under moderate to good RF conditions
- Extremely accurate decoding (major duplication of data and forward error corrected)
- Works extremely well under QRM and QRN conditions - Excellent for sending larger situation reports or databases
-
Disadvantages:
- Requires fairly accurate tuning
- Does not work well under very poor RF weak signal conditions
- Long decoding FEC delay not well suited for short keyboard to keyboard communications
- 1k audio bandwidth is very wide as compared to other digital modes
Olivia 16 Tone/500 Hz - Regional/Local HF Comms
For regional and local portable, mobile and fixed station operations on HF USB under good to poor conditions, Olivia 16/500 is our primary mode for short messages and situation reports and has been chosen for the following reasons:
- EXTREMELY accurate decode, even under the worst conditions (major duplication of data and forward error corrected)
- Very resiliant to QRM and QRN
- Best suited for short messages and situation reports under poor HF conditions
Disadvantages:
- Slow data rate (slightly faster than writing speed)
- 500 Hz audio bandwidth is wider than several other modes
For regional and local portable, mobile and fixed station operations on HF USB under good to moderate conditions, DominoEX11(FEC) is our primary mode for short messages and keyboard to keyboard communications and has been chosen for the following reasons:
- Duplication of data and forward error correction provides good copy under moderate RF conditions
- Well suited for keyboard to keyboard (chat)
- Relatively narrow audio bandwidth (approx. 200 Hz)
- More forgiving on tuning inacuracies than Olivia
- Resiliant to QRM and QRN
Disadvantages:
- Not available on many programs other than NBEMS/FLDIGI and Multipsk
- Not as reliable as Olivia 16/500 under very weak RF conditions
Step 7 – Specifics on Operations and Procedures by Mode
1) Go to Configure/Modems and click the MT63 tab.
2) Click 64 bit interleave long, save configuration, then close (on vs 3.03 this setting is now saved after restarts of the program).
3) Go to Op Mode/MT63, arrow over and click on MT63 - 2000.
### TUNING ###
1) Tune transceiver to desired FM frequency (make sure all DSP, compression and noise blanker settings are disabled and stations operating under weak signal conditions should open the squelch on the transceiver).
2) All stations should always center on 1500 Hz on the waterfall (MT63 always uses a bottom freq of 500 Hz on transmit. When you initialize MT63, the waterfall tx will be set to this default).
3) Transmit and receive some text to make sure all stations are decoding properly. Assuming that all soundcards are properly calibrated, no tuning should be necessary.
(recommended USB frequencies: 3.590, 7.090, 14.109):
### SETUP ###
1) Go to Configure/Modems and click the MT63 tab.
2) Click 64 bit interleave long, save configuration, then close (on vs 3.03 this setting is now saved after restarts of the program).
3) Go to Op Mode/MT63, arrow over and click on MT63 - 1000.
### TUNING ###
1) Tune transceiver to desired HF frequency (always us USB and make sure all DSP, compression and noise blanker settings are disabled).
2) All stations should always center on 1000 Hz on the waterfall (MT63 always uses a bottom freq on 500 Hz on transmit. When you initialize MT63, the waterfall tx will be set to this default).
3) Click tune button in the upper right corner of the program and let it transmit for about 10 seconds. Click the tune button again to go back into receive.
4) RX stations center on the received 1000 Hz tone by tuning the receiver VFO.
5) Transmit and receive some text to make sure all stations are tuned and decoding properly.
(recommended USB frequencies: 3.584, 7.074, 14.074):
### SETUP ###
1) Go to Op Mode, left click, arrow over Olivia, arrow over to 16/500 and left click.
### TUNING ###
1) Tune transceiver to desired HF frequency (always us USB and make sure all DSP, compression and noise blanker settings are disabled).
2) All stations should always center on 1000 Hz on the waterfall.
3) Click tune button in the upper right corner of the program and let it transmit for about 10 seconds. Click the tune button again to go back into receive.
4) RX stations center on the received 1000 Hz tone by tuning the receiver VFO.
5) Transmit and receive some text to make sure all stations are tuned and decoding properly.
(recommended USB frequencies: 3.583, 7.073, 14.073):
### SETUP ###
1) Left click on Configure, left click on Modems, left click the Dom tab.
2) Type in your secondary text (i.e. call sign, tactical call, station location), left click both check boxes for Filter On and FEC, then left click save config, then left click close.
3) Go to Op Mode, left click, arrow to DominoEX, arrow over to DominoEX 11 and left click.
### TUNING ###
1) Tune transceiver to desired HF frequency (always us USB and make sure all DSP, compression and noise blanker settings are disabled).
2) All stations should always center on 1000 Hz on the waterfall.
3) Click tune button in the upper right corner of the program and let it transmit for about 10 seconds. Click the tune button again to go back into receive.
4) RX stations center on the received 1000 Hz tone by tuning the receiver VFO.
5) Transmit and receive some text to make sure all stations are tuned and decoding properly.
Indicates auto transmit and auto receive
Indicates auto start (you will need to use BTU or manually switch to receive)
Indicates auto receive