currently i'm building the infrared object detection sensor with reference from Parallax "Experiment #4: Infrared Object Detection".
I supposed to get the oscillator circuit·tuned to 38000Hz frequency, but the max value i get is only·about 11000Hz with the 1K pot adjusted to zero resistance. If i tuned the resistance higher, the frequency will drop lower.
I already checked the circuit according to the Figure 4.1 in that article,·using all the required components.
Really appreciate if anyone can help.