Induction coupled amplitude modulation system

Claim 2

In a system for coupling the output of an audio amplifier to a radio frequency power amplifier in such manner that a radio frequency signal is modulated by the output of the audio amplifier, a modulation reactor having a core with reactor and primary windings wound thereon, said primary winding being electrically connected to the output of said audio amplifier and inductively coupled to said reactor winding, means electrically conneCting said reactor winding intermediate said radio frequency amplifier an its plate power supply to provide plate modulation of said amplifier, a separate modulation transformer including a magnetic core and a center-tapped winding, means connecting the two ends of said center-tapped winding to the output of said audio amplifier and directly to the primary winding of said reactor, and means connecting the center tap of said winding to a voltage source.

Claim 3

A system as in claim 1 wherein said modulation transformer also includes a secondary winding coupled to said center-tapped winding and adapted for receiving on the order of 10 percent of the output power of said audio amplifier, said secondary winding being connected to an electrode in said radio frequency amplifier to provide auxiliary modulation for said radio frequency amplifier.

Claim 4

A system as in claim 1 wherein said modulation transformer also includes a secondary winding coupled to said center-tapped winding and adapted for receiving on the order of 10 percent of the output power of said audio amplifier, together with means connecting the secondary winding of said modulation transformer to a screen grid in the final stage of said RF amplifier to provide screen modulation in phase with said plate modulation.

Claim 5

A system as in claim 2 together with additional coupling means for applying a portion of the audio frequency amplifier output to at least one radio frequency amplifying stage prior to the radio frequency final amplifier for modulating the radio frequency signal in said additional radio frequency amplifying stage.

Claim 6

A system as in claim 4 wherein said additional coupling means includes an auxiliary modulation transformer having a primary winding and at least one secondary winding, said primary and secondary windings being coupled to each other, means connecting said auxiliary modulation transformer primary winding to the secondary winding of said first-named modulation transformer, and means connecting said auxiliary modulation transformer secondary winding to said additional radio frequency amplifier stage.

Claim 7

In a modulation coupling system, a modulation reactor having coupled primary and secondary windings, said primary winding being connected directly to the output stage of a modulating audio amplifier and adapted for receiving a substantial portion of the output of said audio amplifier, and said secondary winding being connected to the final stage of a radio frequency amplifier to provide plate modulation thereof, a separate modulation transformer having magnetically coupled primary and secondary windings, said last-named primary winding being connected directly to the output of said audio amplifier and adapted for receiving a portion of the power output therefrom, said last-named secondary winding being adapted for connection to said radio frequency amplifier to provide auxiliary modulation thereof.

Claim 8

In a modulation coupling system, a modulation reactor having coupled primary and secondary windings, said primary winding being connected directly to the output stage of a modulating audio amplifier and adapted for receiving a substantial portion of the output of said audio amplifier, and said secondary winding being connected to the final stage of a radio frequency amplifier to provide plate modulation thereof, a separate modulation transformer having magnetically coupled primary and secondary windings, said last-named primary winding being connected directly to the output of said audio amplifier and adapted for receiving a portion of the power output therefrom, said last-named secondary winding being adapted for connection to said radio frequency amplifier to provide auxiliary modulation thereof.

Claim 9

In a modulation coupling system, a modulation reactor having coupled primary and secondary windings, the primary winding being connected directly to the output stage of a modulating audio amplifier and adapted for receiving a substantial portion of the output of said audio amplifier and the secondary winding being connected to the final stage of a radio frequency amplifier to provide plate modulation thereof, a separate modulation transformer having magnetically coupled primary and secondary windings, the last-named primary winding being connected directly to the output of said audio amplifier and adapted for receiving a portion of the power output therefrom, and the last-named secondary winding being adapted for connection to said radio frequency amplifier to provide auxiliary modulation thereof, together with an auxiliary modulation transformer having a primary winding connected to the secondary winding of said first named modulation transformer for receiving audio power therefrom and at least one secondary winding magnetically coupled to the primary winding of said auxiliarY modulation transformer and electrically connected to a stage of the radio frequency amplifier prior to said final stage to provide modulation of at least one electrode of said prior stage.

Claim 10

In a modulation coupling system, a modulation reactor having coupled primary and secondary windings, the primary winding being connected directly to the output stage of a modulating audio amplifier and adapted for receiving a substantial portion of the output of said audio amplifier and the secondary winding being connected to the final stage of a radio frequency amplifier to provide plate modulation thereof, a separate modulation transformer having magnetically coupled primary and secondary windings, the last-named primary winding being connected directly to the output of said audio amplifier and adapted for receiving a portion of the power output therefrom, and the last-named secondary winding being adapted for connection to said radio frequency amplifier to provide auxiliary modulation thereof, together with an auxiliary modulation transformer having a primary winding connected to the secondary winding of said first named modulation transformer for receiving audio power therefrom and at least one secondary winding magnetically coupled to the primary winding of said auxiliarY modulation transformer and electrically connected to a stage of the radio frequency amplifier prior to said final stage to provide modulation of at least one electrode of said prior stage.

Claim 11

A modulation coupling system as in claim 7 wherein said auxiliary modulation transformer includes first and second secondary windings, said first secondary winding being adapted for connection to a radio frequency driver stage to provide plate modulation thereof, and said second secondary winding being adapted for connection to said radio frequency driver stage to provide screen modulation thereof.