What is Pack Roving?

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 strategy 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 is possible to amass a large number of contacts and multipliers resulting in a winning score. There is no reliance on propagation or population because the group is its own source of contacts. Contacts with the general population are made as well but the major part of the score comes 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 from Texas to Nebraska.

As frequently happens when an individual or a group achieves success, they became the target of attacks from others desiring to bring them down. It was no great surprise when the Southern California Pack Rovers came under fire. Significantly the attacks were only coming from a small number of people and they garnered little support. They did make a lot of noise, making it appear that the detractors were more numerous than was really the case. The end result, the ARRL was persuaded to change the rules.

A new unlimited category was introduced where activities such as grid circling and pack roving were encouraged. In the classic rover category a 100 contact limit was imposed between any two rovers.

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.

Ever ready to meet new challenges, N6NB increased the number of 10 band stations to 10. Increasing the number of grids visited has demonstrated that it is still possible to win from the west coast using pack roving.

Predictably the attacks continued but a much anticipated second round of rule changes did not occur so further revisions to the strategy must remain under wraps until needed. In the meantime, a newly introduced club competition will provide fertile ground for the pack roving group.

What is a Toolbox Station?

Each rover is a 10 band station covering 50 MHz thru 10 GHz. The stations consists 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 thru 432 MHz or 1296 MHz.
• A switchbox permitting instant bandchanging.
• A Rubidium reference for the microwave transverters.

Contacts between members of the pack take place 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. (Requires 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.