User's Manual Part 3

116
- Calibration procedure from 66MHz to 860MHz
1. Extract the coupling 5 (Fig. 1) until it stops.
2. Extract the couplings 3 making sure not to short-circuit them.
3.Connect the filter to the Network Analyser, marking the input. Select the frequency of the desired centre
channel and set a SPAN of 50MHz.
4. Act on the tuning rods 1 and 2 until the curve of the band-pass appears in the centre of the screen and
adjust it by means of the coupling 3 to obtain a width of about 10MHz (Fig. 2). The tuning 2, due to the
elliptical system according to which the filter has been designed, will compose the attenuation of the notch as
well as the curve of the band-pass.