I'm considering a multi-single effort in the upcoming ARRL DX Phone
contest, and want to use a run station as well as a mult station. We ran
multi-single at AE9B during the CQ WW Phone contest and it became obvious
that a mult station would have been a great help. But I'm absolutely
stumped as to the mechanics of how you operate both stations, ensuring only
one signal on the air at a time, without completely disrupting any "flow"
the run station might have.
Could someone give me a short "play-by-play" of how operation at a "real"
multi-single with a run station and mult station might go?
Thanks & 73,
-Marty NW0L
martyt@pobox.com
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>From Leigh S. Jones" <kr6x@kr6x.com Sat Feb 3 06:39:41 2001
From: Leigh S. Jones" <kr6x@kr6x.com (Leigh S. Jones)
Subject: [CQ-Contest] Multi-Single - How?
References: <4.2.0.58.20010202222331.00941ba0@pop-server.kc.rr.com>
Message-ID: <0bd701c08dac$16acf960$ede3c23f@kr6x.org>
Multi-single stations:
1) Two computers are used, each runs "CT" or similar logging software, and
each controls one "radio". The "CT" software links the two computers
through a "network" which is actually an RS232 link through serial ports.
2) Usually (and especially in CQ contests) one "radio" becomes the "run"
station, and one "radio" becomes the "multiplier" station using the CT
software to implement the function. One "radio" is set to operate on a
given band, and the other radio is set to operate on another band.
3) In some contests, an "interlock", also known as an "octopus" is wired
between the two "radios". The interlock circuits prevents simultaneous
transmission from the two "radios". In CQ contests, simultaneous
transmissions are allowed (within the framework of other rules regarding the
frequency of band changes), so an interlock is not required. The interlock
is especially useful in the ARRL DX contest and the ARRL November SS
contest.
4) Most multi-single stations must deal with undesirable levels of
cross-talk between the two stations, so bandpass filters are often required
to attenuate cross-band interference, just as in the case of multi-multi
stations. However, optimizing in a multi-single environment usually
requires a degree of flexibility in switching antennas and filters that can
only be implemented through quite complex switching arrangements. A modern
competitive multi-single station might be more difficult and costly to
assemble than a multi-multi station of similar competitive cabability. This
is because it only requires a couple of additional transceivers and
amplifiers to build the multi-multi station, but the competitive
multi-single station requires an incredible switching and filtering
capability. It's worth noting, however, that WX0B has a switching/filtering
capability available at a low price that may be fully competitive.
5) The operator team of a multi-single station is presented with a set of
"band change" choices that are not present in multi-multi environments.
Each operator in a multi-single station must be capable of making "band
change" decisions similar to those presented to a single operator multi band
entry, but will also be required to master operating skills such as
"multiplier passing" and scheduling that are usually considered to be
reserved for multi-multi environments.
Multi-single may seem like an easy entry into the multi-operator arena, but
in fact is not as easy as it seems. A fully competitive multi-single
station (and operator crew), especially for the CQWW contests, is nearly as
difficult to assemble as a fully competitive multi-multi station.
In a CQWW contest, the "run" station operates like a single operator
station. The operator calls CQ or he runs around the bands calling other
stations, depending on which activity is the most profitable one at a given
time. The "multiplier" station runs around the bands calling any station he
finds that is a new multiplier, by virtue of zone or country (or prefix in
the WPX). The multiplier station does not need to prevent simultaneous
transmissions -- he and the "run" station can transmit simultaneously -- but
he cannot make a contact with any station that is not a new multiplier.
There's lively discussion on the CQ-Contest reflector each year as to
whether he is allowed to call CQ within the spirit of the rules. There's
usually very little to be gained by attempting to put a second "multiplier"
station into use due to a "ten minute" rule.
In the ARRL sponsored contests, the multi-single class is strictly limited
to one signal at a time, and the "ten minute" rule takes on a whole
different meaning. It is possible to be fairly competitive (although not
fully competitive) in the ARRL sponsored contests with a much simpler
antenna switching and filtering arrangement than is required in a CQ
contest, but the "interlock" also known as an "octopus" is a strict
requirement for optimization -- trying to do a multi-single ARRL contest
without an interlock is an exercise in futility and conflict.
Nonetheless, in either type of contest, CQWW or ARRL, the key to success is
shortening transmissions -- calls, exchanges, and CQ's -- to a degree that
would otherwise be detrimental to the overall rate if the same station were
to be operated as a multi-operator or a single operator station.
----- Original Message -----
From: "Marty Tippin" <martyt@pobox.com>
To: <cq-contest@contesting.com>
Sent: Friday, February 02, 2001 8:27 PM
Subject: [CQ-Contest] Multi-Single - How?
>
> I'm considering a multi-single effort in the upcoming ARRL DX Phone
> contest, and want to use a run station as well as a mult station. We ran
> multi-single at AE9B during the CQ WW Phone contest and it became obvious
> that a mult station would have been a great help. But I'm absolutely
> stumped as to the mechanics of how you operate both stations, ensuring
only
> one signal on the air at a time, without completely disrupting any "flow"
> the run station might have.
>
> Could someone give me a short "play-by-play" of how operation at a "real"
> multi-single with a run station and mult station might go?
>
> Thanks & 73,
>
> -Marty NW0L
> martyt@pobox.com
>
>
> --
> CQ-Contest on WWW: http://lists.contesting.com/_cq-contest/
> Administrative requests: cq-contest-REQUEST@contesting.com
>
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