High Speed CW for COMSEC

I know many of you are saying to yourselves, "Why do we want to use HSCW". Well, the reason is quite simple. It's called "COMSEC", and it is one of the best ways barring actual encipherment to communicate with others within your group.

The reasons are:

1. It is so fast, that unless one is looking for the transmission, all one hears is a "ping".

2. It can be sent under the noise level, so it is very difficult to find the transmission.

3. The message is usually very reliable, and correct.

4. One can send a reasonable message so fast, that unless the other party to the conversation doesn't have time to engage the program before the message is sent and the transmission turned off. This makes good sense especially when one party is under scrutiny by opposition forces.

Take time to search out the programs available for this mode. It will be well worth the time and effort. One downfall is that the "ping" is so fast, that both stations MUST be pretuned. Take some time to learn how to use this tool. It may save your life, or the life of someone important to you.




All you never wanted to know about High-Speed CW MS Operation

WHAT IS HSCW?

HSCW (or HSMS) is the technique of using very high-speed CW Morse code to communicate and exchange of information.

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

Here are some typical examples:


(1 word = 5 letters) [lpm, letters/minute; wpm, words/minute].

Typical CW 25 wpm 125 lpm

Fast CW 50 wpm 250 lpm (Limit of most "regular speed" MS operation)

Fast-talking SSB 100 wpm 500 lpm
Slow HSCW 200 wpm 1000 lpm
Kinda slow HSCW 400 wpm 2000 lpm
Faster HSCW 800 wpm 4000 lpm (common speed)
Still faster HSCW 1200 wpm 6000 lpm
Very fast HSCW 1600 wpm 8000 lpm
Ultra fast HSCW 3200 wpm 16,000 lpm

You can see that even slow HSCW is *much* faster than 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 wouldn't even 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. Now days we have software programs that are set for HSCW, and make it very easy to encode and decode

SOUNDS TOO SIMPLE.

How do you modify a tape recorder to encode and decode HSMC?


For the past 20 years the European CW 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. By using MSDSP, you can slow it down by 60 times.

But here's a real, example: Cathy, 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 QSOs (at 5000 lpm - 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 lpmHOW 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.

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.

SO IS THIS ACTUALLY SSB PHONE OR MCW OR WHAT?

If properly done, it's CW, but with the zero-beat frequency offset from the dial reading by 2 kHz (with a 2000 Hz 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 actually designated as J2A emission).


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

It actually started clear back in the 1950s. 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. 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 several computer programs that would emulate and go far beyond the capability of the modified audio recorders, HSCW suddenly surged into prominence.

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

The 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 enough radio equipment 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 with the usual peripherals should work. However, all of the software available at this time does require Sound Blaster audio board.

SO HOW MUCH DOES IT COST TO GET ON HSCW?

Like most other aspects of Amateur Radio, this depends upon what you presently have. If you are capable of operating MS, aurora, etc., you probably have a rig that is suitable for HSCW. Nearly all Hams have a computer, and many use it in their routine operations. The one critical piece of equipment at this time is a Creative Labs Sound Blaster stereo audio board or it's equivalent. Most (all?) DSP programs of all types (and there are a number) utilize the Sound Blaster audio board for the conversion. The current HSCW programs are either freeware or shareware.

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

For 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, but the conversion can be difficult on some cassette players. 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.