The goal of the procedures described is to enable valid contacts to be made by meteor scatter (MS) reflection as quickly and easily as possible. Meteor scatter is unlike most other propagation modes, in that neither station can hear the other until an ionised meteor trail exists to scatter or reflect the signals. As the reflections are often of very short duration the normal QSO procedure is not readily applicable and specialised operating techniques must be taken to ensure that a maximum of correct and unmistakable information is received. The two stations have to take turns to transmit and receive information in a defined format, following the procedures as detailed below. Some meteor showers are strong enough to make some of these measures unnecessary, but to encourage use of all generally listed showers there is no reason why the suggested procedures should not always be used. As with operating procedures in general, the virtues of the MS operating procedures are mainly that they are standard and are widely understood throughout IARU Region 1.
Two types of MS contacts, arranged in different ways, may be distinguished:
Prior to any MS activity it is absolutely vital that clocks need to be set to better than 1 second of standard time. Any clock inaccuracy will result in wasted time. Accurate timing of transmit and receive periods is important for two reasons: 1) to maximise the chances of hearing the other station, and 2) to avoid interference between local stations. Accurate timing can be accomplished for example by checking against the time-ticks on standard frequency transmissions, TV Teletext, telephone 'speaking-clock', GPS time signals or the Internet.
The recommended time periods for the different modes are:
This practice gives quite satisfactory results. However developing technology make it possible to use much different periods and amateurs may wish to arrange 1 minute periods for Telegraphy and shorter periods for SSB and MGM especially during major showers. If non-recommended time periods are used the first priority is to avoid causing interference to local stations that are using the recommended periods.
Even though the recommended period for SSB contacts is 1 minute periods a quick-break procedure making a break every 10-15 seconds, in case the QSO can be completed within one long burst, are encouraged during major meteor showers.
In order to minimise the overall interference with other stations standard transmit periods are recommended. Station in central and Western Europe should use second period. All MS operators living in the same area should, as far as possible, agree to transmit simultaneously in order to avoid mutual interference.
Every uninterrupted QSO period must be considered as a separate trial. This means that it is not permissible to break off and then continue the contact at a later time.
These contacts may be arranged on any frequency, taking into consideration the mode and band plan. Scheduled contacts must not use known popular frequencies and the random MS frequencies. Special care should be applied on the frequency selection to avoid interference when using reverse transmit periods according to your location.
The frequency used for CQ calls for random contacts should be according to the IARU Region 1 bandplans.
To avoid -interference, which results from a large number of stations attempting to complete contacts on the various MS calling frequencies, a QSY method is recommended. During the CQ the caller indicates on which frequency he/she will listen for a reply and carry out any subsequent QSO. The procedure for moving a beginning QSO off the calling frequency without losing contact is as follows. If an operator wants to call CQ the following QSY procedure should be used:
If an operator instead of calling CQ wishes to listen for a CQ call the following QSY-procedure should be used:
All modes use the same MS-QSO procedure.
When attempting random SSB contacts, speak the letters clearly, using phonetics where appropriate.
The contact starts with one station calling the other by sending both call signs.
b. Reporting system
The report consists of two numbers:
|First number||Second number (signal strength)|
|(burst duration)||S-units S/N|
|2 : up to 0,5 s||6 : below S2 or below 5 dB|
|3 : 0,5 - 1 s||7 : from S2 to S3 or from 5 dB to 10 dB|
|4 : 1 - 5 s||8 : from S4 to S5 or from 10 dB to 15 dB|
|5 : longer than 5 s||9 : above S5 or above 15 dB|
Note that the number "1" is not used as the first number/burst duration.
Maximum duration of a ping (Underdense Reflection):
|50 MHz||1000 ms|
|70 MHz||500 ms|
|144 MHz||100 ms|
|432 MHz||13 ms|
This means that the duration of bursts (Overdense Reflections) are longer than the above ping durations.
c. Reporting procedure
A report is sent when the operator has positive evidence of having received the correspondent's or his own callsign or parts of one of them. The report should be sent twice between each set of call signs. The report must not be changed during a contact even though signal strength or duration might well justify it.
d. Confirmation procedure
1) As soon as either operator copies both call signs and a report he may
start sending a confirmation. This means that all letters and figures
have been correctly received.
The message can be pieced together from fragments received over several bursts and pings, but it is up to the operator to ensure that it is done correctly and unambiguously. Confirmation is given by inserting an R before the report.
2) When one operator receives a confirmation message, such as "R27", and all required information is complete he must confirm with a string of R's, inserting his own call sign after at least 3 R’s. When the other operator has received the R's, the contact is complete and he may respond in the same manner.
e. Requirements for a complete QSO
Both operators must have copied both callsigns, the report and a confirmation that the other operator has done the same. This confirmation can either be an "R" preceding the report or a string of minimum three consecutive "RRR".
A valid contact is one where both operators have copied both callsigns, the report and an unambiguous confirmation. However no recourse should be made during the contact to obtain the required information, change of frequency, antenna direction, etc. via other methods such as the Internet, DX Cluster, talk-back on another band, telephone etc. Such secondary methods invalidate the meteor scatter contact.
In essence: if anything concerning the ongoing QSO attempt is agreed
through other means than the QSO attempt frequency a new start is
Additional information for communication before and during the MS QSO:
procedure was adopted at the IARU Region 1 Conference in
Miskolc-Tapolca (1978), later slightly amended at the IARU Region 1
Conference in Noordwijkerhout (1987), Torremolinos (1990), de Haan
(1993), San Marino (2002) and Vienna (2004).
From the IARU Region 1 VHF Managers Handbook (v. 7.51, May 2016). For IARU Region 2 and IARU Region 3 please see those.