OCR Text |
Show 4 - . RADIO PRIMER J Diaphragm The thin metal disc In n telephone receiver or transmitter! which Is made to vibrate by periodic attractions of the umgnst in the receiver, re-ceiver, or by the vOicd waves upoken I Into the transmitter. The best dla-: phrsgmi for radio phones are of a uil(.a-alurnlnum composition. COULOMB The unit of measurement measure-ment for the qunntlty of slectrlolt! passing through a circuit. One . lomb la the quantity nf electricity trunsfeo-red by ft current of one am |