From Region 1 VHF Managers Handbook, version 6.12.
7.4 OPERATING PROCEDURES FOR METEOR SCATTER QSO'S (Davos 2005)
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.
7.4.2 Scheduled and Random Contacts
Two types of MS contacts, arranged in different ways, may be
a. A scheduled contact, where two interested stations arrange in
advance the frequency, timing,
transmission mode, e.g. Telegraphy, SSB or MGM and call signs to be
used. Scheduling may be carried
out by exchange of letters or e-mail, by radio via the European VHF
Net on 14,345 MHz, by Internet chatrooms,
b. A non-scheduled contact, where a station calls CQ or responds to
a CQ call, are called "random
contacts". Random contacts are far more difficult and because you
are starting entirely from scratch, it is
particularly important for both stations to follow the standard
meteor scatter QSO procedures described in
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:
- Telegraphy: 2.5 minutes periods.
- SSB: 1 minute periods.
- MGM: 30 seconds periods.
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.
7.4.4 TRANSMIT PERIODS
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
7.4.5 QSO DURATION
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
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
7.4.7 QSY FREQUENCIES FOR MGM
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:
1) Select the frequency to be used for a QSO by checking whether it
is clear of traffic and QRM.
2) In the CQ call, immediately following the letters "CQ", kHz is
inserted to indicate the frequency that will
be used for reception when the CQ call finishes.
3) During the receiving period the receiver should be tuned to the
frequency indicated by the letter used in
the CQ call.
4) When the caller receives a signal on the receiving frequency
indicated during the call and identifies the
reply as an answer on his CQ, the transmitter is moved to the same
receiving frequency and the whole
QSO procedure takes place there.
If an operator instead of calling CQ wishes to listen for a CQ call
the following QSY-procedure should be
1) Listen on a random contact frequency.
2) When a CQ call is received, note the kHz-frequency, which follows
the letters "CQ" in the call. From this
find the correct receiving frequency which the calling station will
use for receiving replies.
3) QSY the transmitter to the receiving frequency, and transmit a
reply during the appropriate period. The
format for the reply can be found in section 8.
4) As the QSO will take place on this frequency, continue to
transmit and to listen, during the appropriate
periods, on this frequency. It may be that the station calling CQ
will not hear your first reply, but may do so
during one or more subsequent periods. Hence there is no need to
return to the calling frequency.
5) The QSY frequencies should take place in the segment according to
the IARU Region 1 bandplans.
a. MGM, kHz-frequency
Users of MGM indicate the frequency they intend to carry out the QSO
by adding the three digits of the
absolute frequency, i.e. the kHz-frequency. For example CQ383
indicates that the station will listen on
144,383 MHz for a subsequent contact.
Example: G4ASR wishes to try a random MS experiment on MGM and wants
to start with calling CQ. He
first checks his receiver in the MGM range of 144,360 MHz to 144,397
MHz and finds a clear frequency on
144,394 MHz. He calls CQ on 144,370 MHz, and he must now add the
kHz- frequency to his CQ call to
indicate on which frequency he intends to listen. In this example he
will therefore call "CQ394" in his CQ
Example: Your receive PA2DW who is calling "CQ274" on the 50 MHz
random frequency. This tells you
that PA2DW will listen on exactly 50,274 MHz.
This proposal does not describe any procedures for QSY operation on
7.4.8 QSO PROCEDURE
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:
Second number (signal strength)
(burst duration) S-units
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
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
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
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
7.4.9 VALID CONTACTS
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 required.
Additional information for communication before and during the MS
"shall we make a sked on 144.388 starting at
1310z, I will start"
"I have QRM, lets move 5 kHz up and start again"
"lets continue for another 15 minutes and start
"thank you for a nice QSO after the QSO has
completed on the radio"
"I only need the final rogers"
"I received a burst from you"
"I received a burst from you but I can not decode
7.4.10 DOCUMENT HISTORY:
This 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).