Rap 'n Tap
[ Home | Contents | Post | Reply | Next | Previous | Up ]
From: John Davidson
Date: 11/16/00
Time: 1:10:26 PM
Remote Name: 206.16.140.254
Ben, When high frequency electricity is connected to a coil and capacitor, the coil and capacitor "rings", like a bell (but electrically, that is). Q is basically the "ringiness" of an LC tuning circuit. If it has low Q, it only "thuds". Low Q is like tapping a drinking glass with a fork, while putting your finger on the rim.
Q makes the radio tune sharp. Losses in the circuit (mostly in the coil) hurt the Q. These losses are complicated, and involve magnetic intertaction between the windings. Making the coil big (4"), using big wire (#12), and spacing the windings about 60% of the wiresize helps tons. But you also have to design the rest of the radio to take advantage of higher Q. _J_