Confessions of the Technically Half Literate
Posted on July 30, 2011
A “eureka moment” was finally reached when today I finally grasped (I hope) how INPUT TO THE FINAL STAGE is calculated.
A “eureka moment” was finally reached when today I finally grasped (I hope) how INPUT TO THE FINAL STAGE is calculated.
As everyone knows, the limit for Part 15 AM broadcast is that “No more than 100mW may be input to the Final RF Amplifier Stage.”
Here is the simple (but wrong) way I saw it.
Suppose you had a loudspeaker and some rule stated, “The input to the speaker may not exceed 10-Watts.” Well, all you would do is get a 10-Watt audio amplifier and things would be fine.
Therefore, in radio, I figured you’d get a transmitter whose 2nd-to-the-last-stage, also called “the buffer,” would have an OUTPUT power of 100mW, which would then go to the Final Stage Input. It’s so simple.
But that’s not the way it is there in reality, where everyone else lives. The actual formula is clearly explained in a July 30, 2011 posting from Radio8Z titled “POWER INPUT,” over on the Big Talker thread.
Take care because an earlier posting has the same title.
