Ok, I'll swap in regular resistors. I have no electrical training, so was just trying to make the circuit as precise as possible. Perhaps pull-up resistor was the wrong terminology. I have using it as part of a circuit to measure the output of a thermistor (to measure air temps in my motor). I have a dataq data logger that measures anaolog DC voltages. In order to log the thermistor, I grounded one lead of the thermistor and sent the other lead to the datalogging input. I also connected this lead to a regulated 5vdc through the "pull-up" resistor. My theory was that the more precise the resistance on that resistor, the more precisely I could calculate the resistance/temp at the thermistor. In the temp range I am measuring, the thermistor has about 50 to 1000 ohms, so I opted for a 1K pull up.