The choice of the ratio of L and C is determined by practical considerations according to the particular use.
For instance, in receiver tuned circuits, in order to achieve a high value of dynamic resistance (required for high gain) the L / C ratio is high. The limitation here is that there is always a minimum value of capacitance inherent in any circuit (this is the 'stray capacitance').
In some applications, it may be required to swamp completely the stray Circuit capacitance, in which case the L / C ratio is low.
The optimum choice of L / C ratio is sometimes difficult. As a compromise, it is convenient to assume that the value of C is 1.5pF per metre of wavelength; thus to tune to 30MHz (ie 10m) a capacitance of about 15pF would be reasonable.
![]() Back |
![]() Index |
![]() Next |
page (c2-1-13) |
Some material Copyright RSGB. |
Click here for important Copyright information |
Web Space provided by Hostroute.com Ltd |
email the Project Co-ordinator |