It is pretty much impossible to win the ARRL VHF and UHF contests from the Western US. We do not have the population density and we do not
get the propagation that some parts of the country do. With the advent of the Rover category a strategy emerged that eliminated the disadvantages
of population density and propagation, creating an opportunity for a win from just about anywhere.
The initial strategy, in use up to 2008, involved a number of ten band rovers travelling together to grid convergencies (points where four grids intersect).
By working each other in all the combinations of grids available at a convergence it was possible to amass a large number of contacts
and multipliers resulting in a winning score.
There was no reliance on propagation or population because the group was the source of many of its own contacts. Contacts with the general population were
solicited as well but, in regions with little activity, most of the score came from inter group contacts.
The practice of a number of rovers travelling together has become known as pack roving
and the practice of rovers working each
other in the many combinations of grids available at a convergence is called grid circling.
A group of Southern California contesters, led by N6NB
, adopted the pack roving, grid circling strategy and
started winning contests. They even tried it out of state, roving through New Mexico, Texas, Louisiana, Oklahoma, Kansas and Nebraska at various times.
As sometimes happens when an individual or a group achieves success, they became the target of criticism. In 2008, ARRL revised the rover rules to create
three categories: unlimited rover, "classic" rover and limited rover. Unlimited rovers can freely grid circle or even operate at fixed stations in two or
more grid squares, but their scores do not count in the club competition.
Classic rovers are eligible in the club competition, but they are limited to 100 contacts with any other rover, effectively ending the practice of grid circling
by classic rovers. Limited rovers are subject to the same rules as classic rovers but they can operate only in the four lowest bands in the contest
(6, 2, 222 and 432 in VHF contests).
The 100 contact limit put an end to grid circling in the classic rover category because it was no longer possible to make enough contacts.
A new strategy was required to meet the challenge of the new classic rover rules. It became apparent that more 10 band rovers would be
required and more grids would need to be visited.
Responding to the new rules, N6NB increased the number of 10 band stations to 13, of which five can be outfitted for an 11th band (24 GHz).
Increasing the number of grids visited has demonstrated that it is still possible to win from the west coast using pack roving.
In this new strategy, in use after 2008, a group of rovers travel together but do not grid circle, saving their quota of 100 contacts entirely for new multipliers.
As before, they solicit contacts on major calling frequencies as they move from grid to grid.
Each rover is a 10 band station covering 50 MHz thru 10 GHz. The stations consist of two main parts: The console situated inside the vehicle
and the transverter box, with antennas, sitting on top of a rotator. The rotator is typically mounted to a baseplate
attached to the vehicle roof rack.
The console typically consists of the following elements:
- Two radios covering 50 MHz - 432 MHz or 1296 MHz. (One is the transverter IF)
- A switchbox permitting instant bandchanging.
- A Rubidium reference for the microwave transverters.
Contacts between pack members are on FM. This speeds up the exchanges by eliminating any need to tune
after changing bands such as would be necessary when using SSB.
A conventional metal toolbox houses the transverters and power amplifiers together with a cooling fan; essential in the 100+ degree
temperatures of the Mojave desert of Southern California. Two short masts attached to the toolbox carry the antennas. Not all stations are
the same but typical antennas are loops or whips for the lower bands, yagis or quagis for 222 thru 1296, loop yagis for 2.3 and 3.4
and a dish with dual band feed for 5.7 and 10 GHz.
The transverters are a mix of DEMI and Kuhne with a Rubidium reference applied to the four highest bands to ensure that all stations are
on the same frequency and no tuning required.
You can download Block Diagrams
of the Toolbox and Console.
(May require Acrobat reader, if you don't have it you can get a free copy here
The Toolbox stations are constantly evolving. The addition of cooling fans has cured the occasional malfunction due to overheating.
The Rubidium references have removed the need for stations to tune around for each other on the microwave bands. This has facilitated an
increase in the QSO rate to 9 per minute between members of the pack.
The stations are capable of real communications and DX contacts are not unusual, even on the microwave bands.
From the AF6O home QTH, N6NB has been worked in seven grids on 10Ghz, toolbox station to toolbox station.