This document describes the Standard Operating Procedures for HSCW operation throughout the IARU Region 2, North and South America. (SSB and slow CW procedures are also covered briefly, below). In following these procedures, all stations using HSCW for meteor scatter communications within the Americas will be operating in an expected and regular manner, ensuring highest communications efficiency. These procedures are not a set of "rules", but rather an attempt to allow all those operating MS to be confident that every operator knows what the others are doing. This revision primarily reflects the ongoing growth and changes of HSCW operation in Region 2, and is an effort to simplify the wording.


The stated frequency is the signal's actual zero-beat frequency, or the frequency that would be displayed by a frequency counter during key-down.

Thus, when using audio-tone injection, the dial frequency is the desired zero-beat frequency minus the tone frequency.

For example: for a schedule on 144.110 - Transmitter VFO is set on 144.108 USB, 2000 Hz audio tone injected. Sked is thus made for "144.110" (or "144.110 ZB"). Receiving station will want approximately a 1500-1800 Hz tone, so will put the receiver on 144.108.3 USB.

This is the method used for many years in Europe, and has become the method used in North America.

(Direct A1A make-break keying cannot be used in North America at the speeds normally used).


On schedules, the Western-most station transmits the first calling period (first minute) of each hour and half hour. (Always check your transmit period against your antenna heading).

(Be especially careful when starting a schedule on the 15- or 45-minute period, as the "other" station actually calls first in order to then be in the correct sequence).

NOTE - This is for the Western Hemisphere, Region 2. In other parts of the world the reverse sequencing is used. ("Western station transmits first" has been the procedure for North America since the 1950's, so it's a little late to try to change now).

If headings are due north-south, then the Southern-most station should transmit the first calling period of each hour and half hour.

DXpeditions often run all schedules using the same sequence, regardless of direction (recommended).

NOTE that it is very dangerous to just say "odd" or "even". While it may seem obvious to you, if you say, for example, "odd" or "odd minute," this can mean EITHER the first or the second minute, depending entirely on the other operator's frame of reference! Don't miss a QSO. Simply state everything in the manner that will cause the least confusion. The Western-most station calls the FIRST transmit period of the hour and half hour.

For CQs, either period may be used, though standard sequencing is preferred. See below under CQs.

For both schedules and CQs, a period of one minute has become standard for HSCW operation. If shorter periods are desired, this must be confirmed with the other station, since this would not be a current HSCW standard period. (In Region 2, because of the standard speeds, periods longer than one minute are not used).


The same as for any mode - an exchange of both call signs, an exchange of some type of information or report, and an exchange of confirmation of the same.

When a station copies both calls, he sends calls and report.

If he gets both calls and a report, he sends his report & Roger.

If he gets report and Roger, he sends Rogers.

When both get a pair of Rogers (you must have at least two to be sure!), the QSO is officially complete. However, the other station may not know this. So it is customary to then send "73" to let the other station know that it's complete, even though the "73" is not required for a complete QSO.

A typical exchange:

W4HHK sends: N1BUG W4HHK N1BUG W4HHK etc. for one minute.

N1BUG sends: W4HHK N1BUG W4HHK N1BUG etc. for one minute.

W4HHK copies both calls on short, weak ping(s), sends: N1BUG 26 W4HHK 26 N1BUG 26 W4HHK 26 etc. (Note that everything repeats very rapidly, with no long runs of any one piece of information. HSCW uses fractional-second pings. Repetition of the same information defeats its advantages).

N1BUG copies both calls and the report on a long, strong ping, sends: R37 R37 R37 etc. (No calls).

W4HHK copies Roger and report, sends: RRRRRR. (Obviously, no calls are being sent now!)

N1BUG copies Rs. QSO is complete. Tells W4HHK that he has everything by sending: 73 73 73 73.

W4HHK copies the 73s, also sends 73. (Or, he may simply quit sending).

Note that information previously received by the other station is not repeated as the sequence progresses.

There may be a slight variation in the exact way this is done, depending upon what is received on the first pings. If a station first receives both the calls and the report before receiving only the calls, he would then skip directly to the Roger and report, etc., as there is no reason to waste time sending what has already been received. HSCW is meant to be very efficient.

Note that this sequence is not the same as is used for MS operation in Region I, and also may not be exactly the same as the "default" settings in the WinMSDSP transmit boxes. (These can be edited, of course).

IDENTIFYING: When the schedule progresses to the "Roger, Report" and later sections, calls are no longer being sent. To remain legal, the simplest method is this: every ten minutes jump back to the first (calls-only) transmit buffer for about one second, then immediately return to the current transmit buffer. Since this is not an unmanned, automatic type of transmission, this satisfies the current US FCC R&R.


Except when something special is required for a specific contest, an exchange of any information is valid for a QSO. The commonly-accepted (and expected) exchange for HSCW MS operation is the burst duration-signal strength report ("2-number" report). This is now standard everywhere for HSCW operation.

Other sometimes-used exchanges:

Burst length "S" report. Standard in North America since the 1950's for slow CW & SSB. Used by some for HSCW, but not the preferred exchange.

Grid square. Required for some contests. Otherwise should not be used on HSCW. (See below for SSB).

1 - Ping with no info. (Not sent)
2 - ping, up to 5 sec in length 6 - up to S3 in strength
3 - 5-15 sec in length7 - S4 to S5
4 - 15-60 sec burst8 - S6 to S7
5 - over 60 sec burst9 - S8 and stronger

Note that there cannot be any confusion between the first and second number as the ranges do not overlap; also note that the second number is not itself an exact S-meter reading. (The duration report suggested here is slightly different from the European standard and also from some of the older North American charts). This is now the preferred exchange for HSCW operation. But, if the other station uses a different reporting system, simply copy what he sends and send your (proper) report.

The typical ping will have a Burst Duration of 2, a Strength of 6 or 7. (This is a weak-signal mode).

Once you have started sending a report, it is NOT changed during that schedule, even though you suddenly get a much better burst. E.g., if you start sending "26", this is the report you would continue to send, even if you next get a "38-quality" ping. Changing the report will probably result in the loss of a contact.

On High-Speed CW MS operation, it is possible to request a missing piece of information.
BBB - Both call signs needed
MMM - My call sign needed
YYY - Your call sign needed
SSS - Report (or whatever report/information exchange used) needed
UUU - Ur keying is unreadable

(Use "U" when needed. Remember that the other station cannot monitor his keying).

These "requests for repeat" letters are used only when the other station mis-copies something and jumps ahead in the sequence. Thus, they are seldom needed (but very valuable at that time).

When these are used, nothing but the appropriate string of letters is sent. (E.g., "YYYYYYYYYY").

The other operator should respond by sending only the requested information. (E.g., "W8WN W8WN W8WN").

When the requesting operator has the needed data, he returns again to the proper exchange sequence.

This has proved to be very effective when both operators are aware of this and use it if they observe that the other station has mis-copied something and is sending the wrong data, or when the other operator may be accidentally sending from the incorrect transmit buffer (which we all have done!)



For CQs, a speed of 2000 to 4000 lpm is recommended. 4000 lpm has now become standard.

SCHEDULES - If you intend to run slower than about 3000 lpm or faster than about 7000 lpm on a schedule, it is necessary that this be confirmed with the other station. He may not be set up to handle the slowest or fastest speeds. (It is very important to know the approximate speed to be used. If you try to play back a ping either much too fast or much too slow, you not only will be unable to copy it, you may not even be sure that you are hearing a signal! Strange, but it is very difficult in these cases to know if you are set much too fast or too slow).

For schedules, always determine what speed the other operator wishes to use.

The most effective schedule speeds with current equipment and techniques are 6000-10,000 lpm. The signal-to-noise ratio becomes poorer above about 12,000 lpm; thus, higher speeds are not recommended for routine operating, although a number of stations are testing various techniques for use at these higher speeds.



Schedule frequencies are arranged between the two individual stations on any seemingly unused frequency.

On 144 MHz, operation is normally conducted between 144.100 and 144.200 to avoid interference with EME operation below 144.100, and with SSB operation near and above 144.200.

At this time, most 50 MHz schedules are being made near 50.245, and between 50.300 and 50.400.

(Speeds, frequency, exact procedures, etc., must always be confirmed between the two stations, especially if something different from the standard procedures is desired).


On 2 meters - 144.100. Call, listen, and operate on the same frequency, unless there seem to be several stations operating there. If this is the case, the CQ-Letter method should be used.

On 50 MHz - 50.300. Because of nature of 6 meters, the CQ-Letter method should normally be used .

CQs use a one-minute sequence. Either period may be used, since they could be answered from any direction, though the standard sequence is preferred (see under sequencing).

For other VHF/UHF bands, no calling frequencies have been decided on. Due to the difficulty of operating MS on 220 and 432, all operation is currently by means of schedules.

CQ-LETTER - If it is apparent that there are several operating, immediately following the letters "CQ", a specific letter is inserted to indicate the frequency that will be used for reception when the CQ sequence ends. This letter indicates the frequency offset from the actual CQ calling frequency used. For example, CQE would indicate that the CQing station would listen 5 kHz above his CQ frequency. In all cases the letter used indicates a frequency higher than the CQ frequency. When the CQing station hears a call on the offset frequency (not on the CQ frequency, for he is not listening there), he/she immediately then also moves to the offset frequency, and the QSO takes place there with BOTH stations now transmitting and receiving on the new designated frequency.

For example:
CQA - Up 1 kHz
CQE - Up 5 kHz
CQZ - Up 26 kHz
CQAA - Up 27 kHz. Etc.

Note that the letter indicates the number of kHz higher than the CQ frequency. It does not indicate any specific frequency. Thus, if a DXpedition is using some other frequency for CQs, the letter again indicates the number of kHz higher where they are listening and to which they will QSY for QSO attempts.


If it is only a straight CQ, you call and receive on the frequency that is being used for the CQ.

If it is a CQ-letter, you change both your transmitter and receiver to the indicated frequency.

You then call and listen on this new frequency. When (if) the CQing station copies both calls, he will also QSY to this new frequency and the contact will take place there.

When you call the CQing station, you use the standard 1x1 calls (e.g., W4HHK N1BUG W4HHK N1BUG, etc.).

When the CQing station copies you (on the new frequency, if a CQ-letter has been used), he will respond with both calls and a report.

The calling station continues with the 1x1 calls until he copies the calls and report, then switches to the Roger-Report, and then on through the usual sequence.

(If the CQing station gets only partial calls, he should QSY and call "QRZ?" on the new frequency).


Schedules are always made in Universal Time. However, for evening schedules, the local time/day may also need to be stated to be certain that the date is understood properly.

These are the current HSCW Procedures for Region 2. If you wish to experiment with variations, that is up to you and the other station; this is the way the procedures grow and improve. But by using these for routine operating, you are less likely to disappoint the other station by seemingly failing to show up for the schedule, or by not knowing what to do!


SSB exchange requirements and procedures are the same as HSCW procedures, with the following changes:

  1. The period is normally 15 seconds, with the Western station calling first at the start of each minute.
  2. Random MS operation does not necessarily follow an exact sequence. Break-in is commonly used.
  3. Information exchange (report) is usually the burst-length "S" report (S1 through S5) on schedules, Grid Squares on random contacts. For random contacts, yet other exchanges are sometimes heard.
  4. Phonetics must be used for random operation; they should not be used for schedules.
  5. For CQs, the usual SSB calling frequencies are often used during periods of low activity. However, during the peaks of major showers, they quickly become overcrowded. Frequencies every 5 kHz above and below the calling frequencies are then commonly used.
  6. On SSB, attempts are usually made to complete the entire QSO on a single long burst. Thus, break-in procedures should be used whenever possible.


Again, the procedures for CW are the same as for HSCW or SSB, with the following changes:

  1. The period may be 15, 30, or 60 seconds. Thus, this must be stated.
  2. The exchange (report) is normally the burst-length "S" report.
  3. Random CQs may follow the 15-second sequence, or they may be short calls with a break.


Region 1 Meteor Scatter procedures can be found at URL (Due to be revised soon).

This Region 2 document covers only the basic procedures. For more General HSCW information, go to or one of the other HSCW Home Pages and follow the links. The HSCSW FAQ, Semi-Technical FAQ, MSDSP Operating Tips, several charts, and many other papers are available to assist with both operating and technical information.

(Rev 1999/09, V. 11 - edited by W8WN) hscw-sop.doc, hscw-sop.html, hscw-sop.rtf,