We are going to adjust the DC voltage level at the point on the right hand side of the diagram shown as the information signal input. To do this, we need a convenient way of adjusting the DC voltage level applied to the base of the transistor. Fortunately, we have such an adjustment easily available. It is the Carrier Frequency preset. The output frequency is available at the left-hand side of Figure 86 but, to avoid loading due to the oscilloscope, we are going to use the amplified output at tp34 for the frequency measurement. Ensure that the Carrier Frequency preset to set to minimum (fully counter- clockwise). Record in your workbook the oscillator output frequency measured at tp34 and the DC input voltage measured at tp2 Turn the Carrier Frequency preset to its maximum value (fully clockwise). Again record in your workbook the oscillator output frequency measured at tp34 and the DC input voltage measured at tp21. If you have a frequency meter available, it could be used to take a series of readings as the carrier frequency preset is increased to enable a graph of DC volta oe/frennuency ontrut to the plotted