How long with a set of ten NiMH batteries last in a contest situation? That is the question I set out to answer in the NA QSO party. The contest started with ten batteries fresh off the charger. I ran the entire contest at about 2 watts to a set of dipoles up in the trees behind the house. First up were 10 and 15 meters with the Elecraft K2. This was the most power hungery rig I used so I kept QSOs to a minimum going only for new multipliers on the band.
Then I moved on to 20 and later to 40 meters using the Elecraft K1. This rig uses a lot less energy. In fact is was so efficient I never did manage to run the batteries all the way down. When the contest was over the K1 display showed 11.9 volts on recieve and 11.2 volts on transmit. With the protection diode in the circut the voltage on the batteries never went below 11.6 volts. With ten batteries I should have been able to take them all the way down to 10. Volts. That low a voltage would not have been a problem for any of the rigs I used for the contest. As it turned out these two bands neted the majority of the contacts.
Later in the evening I moved down to 80 meters and used the Wilderness Sierra for this band. It is also a very efficient rig, drawing a minimum of current. Nearly a quarter of the contacts were made on 80 meters.
The summery table for the contest is shown below.
This was one fun contest. Next time I'm going to have to plan better so as to run the
batteries all the way down. Of course it did not help this time when I quit the contest two hours
early when I felt a cold comming on. I actually ran only 7 hours and 40 minutes in the contest and
am sure I could have gone another two hours without a problem. I ran mostly in search and pounce mode,
not because I was runnnig QRP but rather to conserve the batteries.