HSCW (or HSMS) is the technique of using very high-speed CW Morris code to communicate and exchange short bits of information by using the many, many underdense "pings" caused by the tiny meteors that constantly bombard our atmosphere.

(Note that the procedures and standards in this FAQ are based upon North American HSCW operation, which sometimes differ from European HSCW MS. If you live in Europe, the Region 1 HSCW Procedures are found at http://www.scit.wlv.ac.uk/vhfc/iaru.r1.vhfm.4e/5B.html).

HOW DOES THIS DIFFER FROM, SAY, SSB MS OPERATION?

During the peak of a major shower, when overdense trails produce frequent signals for several seconds, short-sequence and/or break-in SSB may be more efficient. But at all other times, when overdense trails are not available, HSCW is able to use the occasional and sometimes frequent underdense fractional-second pings to transmit the same amount of information.

JUST HOW FAST IS HSCW? IS IT MUCH FASTER THAN SSB?

Here are some examples:
(lpm = wpm x 5) [lpm, letters per minute; wpm, words per minute].
Typical CW 25 wpm 125 lpm
Fast CW 50 wpm 250 lpm (Limit of most "regular speed" MS operation)
SSB 250 wpm 1250 lpm
Slow HSCW 300 wpm 1500 lpm
Kinda slow HSCW 400 wpm 2000 lpm (used for slower CQ's in North America)
Faster HSCW 800 wpm 4000 lpm (common schedule speed in North America)
Still faster HSCW 1200 wpm 6000 lpm (used for many skeds now)
Very fast HSCW 1600 wpm 8000 lpm (yes, still a good sked speed, using MS_DSP)
Ultra fast HSCW 3200 wpm 16,000 lpm (not recommended, S/N Ratio bad. But has been done!)

You can see that even slow HSCW is as fast as most SSB operators can talk, except maybe for those whose occupation is auctioneering! And receiver tuning and signal strength requirements are not as tight.

SO JUST HOW SHORT CAN THESE PINGS BE AND STILL GET USABLE INFORMATION ACROSS?

Very short! In fact, for HSCW, pings or bursts longer than two or three seconds are exciting but are almost a nuisance! We'll leave it up to you do the actual math. But a 1/10th second ping can propagate a complete set of calls at the medium or higher speeds! This might produce a full syllable on SSB!

YOU CAN'T COPY THAT BY EAR! AND THE CW DECODERS I'VE SEEN COULDN'T HANDLE ANYTHING LIKE THIS. HOW DO YOU DO IT?

Right. The idea is simple. Use a device to slow the code down to something readable. Then copy by ear what has come through.

SOUNDS TOO SIMPLE. HOW?

For over 20 years the European MS operators have been modifying standard audio-cassette recorder motors so that their speed could be varied. This worked well enough for speeds up to about 1500 lpm. Now there are computer programs that will do the same thing much better and at much higher speeds.

SO THE MACHINE DOES ALL THE WORK?

Hardly! It takes the incoming signal, saves it, slows it down, plays it back at a slower speed, and probably heterodynes it to a higher pitch for easier copying. The operator must still do the actual decoding of the signal. The computer or other device slows the speed down, but it is still up to the operator to dig it out of the noise and actually copy it. This is a skill that does not readily lend itself to a machine! While a machine could possibly be built to do this, the technical requirements would be very tight. The brain substitutes for all of this expensive and unavailable equipment!

I HAVE TROUBLE WITH 5 WPM CODE. GUESS THAT LEAVES ME OUT.

Not necessarily. Using CoolEdit, a .WAV file editing program, it is possible to display and read the code visually off the screen. Or by using MSDSP, you can slow it down by 180 times!

But here's a real, recent example (12/97). Our daughter Val, WD8KVD, licensed about 18 years ago, came for a visit. She didn't like code, had only half a dozen CW QSO's as a Novice. Her real interest was emergency/public service work. But seeing HSCW at work here fascinated her. She learned to use MSDSP in 15 minutes and also discovered that she still remembered some of the code. In three schedules, she made three HSCW QSO's (the first two at 5000 lpm, or 1000 wpm) because she could slow the code down. Since the signals were often down in the noise, she could also play back a ping a second time to be sure what she had copied. (On her third schedule, she transmitted at 8600 lpm and received at 8500 lpm, making her not only the fastest woman in the world on CW, but at that time holding the absolute world record for HSCW speeds. The full account, with JPG photo, available on the W6/PAØZN HSCW Hub Web site.

HOW DO YOU GENERATE CODE AT THAT SPEED? MY KEYER GOES UP TO ONLY 99 WPM.

There are several computer programs that will generate HSCW code. Programs commonly used for transmit-only at HSCW speeds include MSSOFT, CWKey, and PCKEY. MSSOFT can be found on the OH5IY Web site (this program has many other parts besides the transmit portion and is needed for any type of MS operation). This is used by many of the European HSCW operators. PCKEY, which runs under DOS or a DOS window of W3,1, is perhaps one of the simplest to run and is very versatile. The documentation is not in English, but the Help screen is. It can be downloaded from the KD5BUR/KM5PO Web site and others. CWKey, used by many EME operators, is currently being modified to also run at HSCW speeds. It is available on the W5UN Web site. Also, there is one (MS_DSP by 9A4GL) that both transmits and does the receive conversion. A programmable keyer, the CMOS Super Keyer 3 (August 1995 QST), is capable of speeds up to 5000 lpm. And some are using CoolEdit, an audio wave file editing program, in a Windows-95 environment, for both transmitting and receiving. (By the time you read this, the above notes may be out of date. See further questions below, the "Semi-Technical FAQ", and the links and notes from the main HSCW Web site on these and still other programs).
Note - in early 1999, a new keyer kit was being tested; a new audio filter kit, also capable of sending and receiving HSCW was being prepared for the market; and a W95 HSCW program was being worked on. Watch the news bulletins for further.

HOW DO YOU KEY THE TRANSMITTER? I DIDN'T THINK RIGS COULD BE KEYED AT THOSE SPEEDS.

Few rigs can be keyed in the standard fashion at much more than 100 wpm (500 lpm); some won't sound good even that fast. The standard practice is to key a pure 2000 Hz audio tone and inject this into the mike jack. (Note - the speeds, tones, and procedures in this FAQ are the North American version. In Europe speeds are usually somewhat slower and some of the procedures and standards differ).

SO IS THIS ACTUALLY SSB PHONE OR MCW OR WHAT?

It's CW, but with the zero-beat frequency offset from the dial reading by the frequency of the tone injected into the mike jack. Recall that on SSB, a single tone simply gives a steady, pure carrier output. Key this tone and you have a CW signal! In fact, this is the way a number of older SSB transmitters generated a CW signal! (By the way, this is designated as J2A emission, according to the ARRL's FCC Rule Book).

YOU SAY YOUR ACTUAL TRANSMIT FREQUENCY IS OFFSET FROM THE DIAL READING? ISN'T THAT CONFUSING?

Yes, it can be, and this cannot be helped. But remember, with modern rigs, when you switch to CW, your signal is also shifted about 800 Hz off frequency. More on the frequency determination problem is covered in a question below and also under the "Procedures", available at this Web site.

HOW LONG HAS HSCW BEEN AROUND? I HAVEN'T HEARD MUCH ABOUT IT BEFORE.

It actually started clear back in the 1950s with the pioneers of MS operation. They would transmit at higher speeds, record bursts onto reel-to-reel audio tape, then slow it down for playback. This was limited to a maximum of only a 2-times speed reduction, however (or 4 times, for those who had a 15- ips machine). This was too cumbersome and never caught on. But then about two decades ago the Europeans pioneered the technique of modifying the motor speed controller of a cheap audio cassette recorder. Because of the availability of SSB, this never was done much in North America. But in 1997, with the appearance of two computer programs that would emulate and go far beyond the capability of the modified audio recorders, HSCW suddenly surged into prominence over here.

SORRY, BUT I DON'T OPERATE VHF DX AND DON'T UNDERSTAND ANY OF THIS.

We're sorry, too, for you really don't know what you're missing! But this FAQ was designed at the request of several VHF operators who have been on VHF DX for awhile, but had no knowledge about HSCW MS operating. A background on VHF and its many propagation modes has filled many books. If you can find one, Ed Tilton's "The Radio Amateur's VHF Manual" is still probably the best, even though it's many years out of print. Another necessary book is "Beyond Line of Sight", edited by Emil Pocock.

WHAT KIND OF RIG AND COMPUTER DO I NEED FOR ALL THIS?

The radio equipment is much the same as needed for any other type of VHF DX operation. If you can operate SSB MS, aurora, or tropo DX, you probably have radio equipment that is suitable for HSCW MS. A common setup would be a multi-mode two-meter transceiver, 150-watt amplifier, and medium-size horizontal beam. (All DX operation on VHF is done with horizontal polarization). Of course, more power is helpful. But HSCW has been successfully done with less than 10 watts into a medium-size Yagi at each end!

For the computer, a '386 or better should work, with the usual peripherals. However, nearly all of the software available at this time does require a true Sound Blaster audio board. (See some of the other questions for HSCW methods without a computer. Also, see the "Semi-Technical FAQ" for a more complete discussion on computers).

HOW DO I SLOW DOWN THE CODE TO A USABLE SPEED?

For over twenty years the Europeans have been modifying cassette audio recorders. This works OK for up to about 1200-1500 lpm. (This would appear to be a simple, inexpensive method of receiving HSCW. And you are limited to a maximum speed of about 1200 lpm. But it has worked for many years in Europe. If you have a computer, this is the recommended method at this time. If you do not and would like an evening project, give the modification a try. Conversion information is available on the N1BUG Web site).

There is a German Digital Tape Recorder (emulator) kit available which is becoming popular in Europe. Because of its price and the fact that it is designed for European style HSCW operation, at this time none of the DTR's are known to be in operation in North America. See the Web sites for more.

Most North American operators use the computer and a true Sound Blaster 16 audio board.

JUST WHAT PROGRAMS ARE AVAILABLE?

The program used by most is MS_DSP (or MSDSP) by 9A4GL. It both transmits and receives, and has many enhancements. It currently is a beta version with some bugs. See the "Operating Tips" and other helps concerning MSDSP on the W6/PAØZN Web site.

A second program, and the first one out, is SBMS, by DL3JIN. It is a receive only, no frills program, that runs either under DOS or in a full-screen DOS window of Windows. Some have had problems understanding the need for the virtual RAM disk, and there is a simpler method of setting it up. Read the documentation carefully or see the "Semi-Technical FAQ" for more on this.

A program used by several operators is CoolEdit96. This is a wave file editor. But it can be used (under W95, with a fast computer) for both sending and receiving. While more awkward for many (and it requires the version of the program which runs under Windows 95), many are using it quite successfully. This is the "visual" means of decoding the HSCW, as it is sometimes called. See the K0SM Web site for more.

The two programs, PCKEY and MSSOFT (with its many other features) do not receive but transmit only. See the other questions here, the "Semi-Technical FAQ", and the links from the various Web sites for more.

And, as noted above, watch the news bulletins in the next year or so for the possibility of several new programs and devices.

SO DOES THIS SOFTWARE ACTUALLY WORK?

Most definitely! But at this time (early 1998), all available software is in a state of development and flux. Whatever we recommend now may be out of date in another 6 months! Check the several HSCW Web sites to see what is current and follow the links.

I DON'T USE A COMPUTER. DOES THIS MEAN I CAN'T WORK HSCW/HSMS?

Not Blue
Sets the color and intensity of signals in the Buffer Display Area. Values for red, green, and blue must be in the range 0 to 63. 63,0,0 produces pure red at maximum intensity. 31,31,31 produces a white display at 50% intensity. Any combination of values may be used.

ForceVESA
Changing this may help if you have display problems. Valic values are 0 and 1.

FPU
Define whether or not math coprocessor is present. Transmit signal quality will be better if using a math coprocessor. 0=no coprocessor, 1=coprocessor present. Consult your computer's documentation to confirm that a coprocessor is installed.

SpaceDelay
SpaceDelay ensures that you have ample time to react to hearing a ping and successfully capture its signal to one of the small buffers. Pressing the SPACEBAR while recording marks a 15-second portion of the main buffer which will be transferred to the next-available small buffer when the ENTER key is pressed. SpaceDelay sets the amount of time in milliSeconds by which the beginning of this portion precedes the actual spacebar keypress.

Example: If SpaceDelay is 2500, then the data which is captured to the small buffer will be the main buffer data extending from 2.5 seconds before the spacebar keypress to 12.5 seconds after the keypress. If you press the spacebar immediately upon hearing a ping, you could then wait up to 12.5 additional seconds after hearing the ping, looking for subsequent reflections to include in the capture, before pressing Enter to complete the capture. The small buffer will then contain the first ping plus any pings which have occurred up to the time at which you pressed the Enter key.

Valid values are 1 to 9999.

TXSpeed
Defines transmit speed in LPM (letters per minute). Valid values are from 100 to 16,500. The defalt value is 2000 LPM.

TXTone
Defines transmit tone frequency in Hz. Valid values are from 100 to 5400. Upper limit of valid values also depends on the sampling rate, so the upper limit is sampling_rate/2. 2000 Hz is the default, and is the recommended value for speeds up to 8000 LPM.

TXPort
Define which serial or parallel port to use for PTT keying. 0=none, 1=COM1, 2=COM2, 3=COM3, 4=COM4, 5=LPT1, 6=LPT2. On serial ports, the RTS line is keyed; on parallel ports, DATA-0 is keyed.

PTTActive
Enables the PTT switching signal if one is specified in TxPort. The PTT signal is switched ON whenever Tx audio output is being generated. This includes normal Tx periods as well as TUNE periods. 0=Disabled, 1=Enabled.

TXDelay
Enables the PTT switching signal if one is specified in TxPort. The PTT signal is switched ON whenever Tx audio output is being generated. This includes normal Tx periods as well as TUNE periods. Specifies the number of milliSeconds delay between the OFF-to-ON transition of the PTT signal and the first transmitted character of Tx output audio. Choose a value which allows ample time for all Rx/Tx changeover functions in your rig to be completed before the first transmitted character is sent by MSDSP.

MyCall
Defines your callsign (maximum of 8 letters).

Period
Defines the duration of period, only 0, 1 and 2 are valid values: 0=disabled, 1=1.0 min period, 2=2.5 min period. Only 1 minute is generally used in North America. Both 1 and 2.5 minute period is common in Europe.

AutoRecord
Defines whether to automatically start recording after receive period is finished. 0=no, 1=yes.

LoopRecording
Defines whether to continue recording in a loop (start over at beginning of main buffer when it becomes full). LoopRecording only works if AutoPeriod is off. 0=no, 1=yes.

RecordSource
Selects which sound card input signal will be processed by MSDSP. 0=Microphone, 1=LineIn.

MasterVolume
Defines the volume of MASTER mixer. Valid values are 0 to 15. Try 12 to 14 and adjust from there.

MasterChannel
Defines which speaker will be used on stereo sound cards (0=none, 1=left, 2=right, 3=both). Try 3.

WaveVolume
Defines the playback volume. Valid values are 0 to 15. Try 12 to 14 and adjust from there.

WaveChannel
Defines which channel will be used for playback (0=none, 1=left, 2=right, 3=both). Try 3.

LineInVolume
Defines the recording level. Valid values are 0 to 15. Start with 12 to 14 and adjust from there.

LineInChannel
Defines which channel will be used for recording (0=none, 1=left, 2=right, 3=both). Try 3.

TX1 through TX6
Defines the transmit texts. Here you can use macros: %M for MyCall, %T for ToRadio and %R for Report.

Contents

2.1 Starting MSDSP

Before starting MSDSP, your sound card must be initialized (if necessary). Also the BLASTER environment variable must be set in your AUTOEXEC.BAT file. This line should take the form SET BLASTER=A220 I5 D1 <rest> (assuming address 220h, IRQ 5 and DMA 1, which may be different on some systems). <rest> depends on your sound card. Your mouse driver should also be loaded prior to starting MSDSP.

Start MSDSP by running MS_DSP.EXE.

Contents

2.2. User interface

On the top of the screen are 9 buttons, one for [Main buffer] and 8 for secondary buffers. The main buffer holds, depending on the Rx period configured, either 1 minute or 2.5 minutes of received signal. Each of the secondary buffers holds 15 seconds of signal, independent of the configured sampling rate or the Rx period. You can click on those buttons to switch between buffers. [Main buffer] has an [x] button for clearing it. The other 8 buttons have a button for pull down menu where you can choose from the following actions:

Load - import saved signal from hard disk
Save - store signal in buffer to hard disk (if buffer is empty this option is disabled)
Clear - clear the contents of buffer (this is disabled if buffer is already clear)
Volume - change the volume of signal in buffer (disabled if buffer is empty).

Below every button is a small window which is dotted if there is a signal in that buffer.

The main buffer is for recording. When you click on the [REC]ord button (Record button is only available if main buffer is active) main buffer will be filled with signal coming from your rig to Line In on your sound card.

When you hear a ping or burst coming from your rig, immediately press SPACE. (Note: alternately, you may click with your left mouse button in the buffer display area to select the area where the ping signal is located). When the ping has ended, hit ENTER. This will transfer the marked area to the first empty buffer. (Note: alternately, you may transfer the selected segment to a specific secondary buffer by clicking on one of the numbered buttons adjacent to the [COPY] indicator on the left side of the screen). When you press SPACE, a blue rectangle will appear to indicate the 15-second segment of received signal which is selected to be transfered to one the secondary buffers when you hit ENTER.

The blue rectangle may be repositioned at any time prior to the actual transfer. This is done by pressing and holding the left mouse button, positioning the marker with the mouse, then releasing the left mouse button. Any number of segments may be transferred to secondary buffers. If you manually select a buffer to which the ping is to be saved, and if data already exists in the target scondary buffer, it will be overwritten by a new transfer and no warning is given. Recording will automatically continue to the end of the Receive period. When your Receive period is finished, you can listen to what you transferred to secondary buffers during your Transmit period.

When you click on the [PLAY] button (or press P) the program will playback from the begining of the active buffer. Clicking on the [PICK] button (or press I) will playback starting at a position that you have previously selected by clicking with the right mouse button in the buffer display area. While playing (and also if not playing) you can change the Play speed scroll bar and the Play tone scroll bar. Play speed defines the playback speed. This should be -10 if you want to slow down 10x. If Play tone is none then the playback signal tone will not be corrected. When Play tone is set to some frequency then the playback signal will be approximately that frequency modulated with the recorded signal. This is useful if you record a signal of 2000lpm at 1000Hz. If you slow down 20x the signal will be at 1000/20=50Hz and it will be difficult to hear. Play tone enables an "up-converter" effect in MSDSP. Play speed and Play tone have one button on the right of scroll bar to disable/enable that efect. If you have a three button mouse, you can use the middle button to toggle (disable/enable) both effects (speed and tone). There are also available buttons [CROP] and [CUT]. These buttons are only available when something is selected in the main buffer. [CUT] will clear the selected area. [CROP] will delete all except the selected area. Click on the [MIXER] button to change the mixer settings for Master, Wave and Line In. There are also [+] buttons, if you are using a stereo sound card then you can disable (mute) the left or right channel (Note: this may not work on some sound cards). Click the [QUIT] to exit MSDSP. You will be asked if you are sure you want to quit. Type Y to quit MSDSP. As you move the mouse over various screen controls, an explanatory message will appear in the status line at the botom of the screen.

SPACE - ENTER usage: If you hear a ping or burst while recording, press SPACE to mark the beginning of the area to copy. The selected area will begin some time before you press space (this time is defined in MS_DSP.INI as SpaceDelay). When an area is selected you can press ENTER to copy the area to the first empty secondary buffer (if there are no empty buffers, it will be copied to the buffer #8. If buffer #8 already has a signal saved to it, this will be erased and the new material will be saved there).

Note: The [FFT] and [Dcode] buttons are not yet available and may be enabled in future versions of the program.

For Transmit there are