To: WSFAlist at keithlynch.net Date: Fri, 23 Aug 2002 15:08:04 -0400 Subject: [WSFA] Re: Looking backward From: ronkean at juno.com Reply-To: WSFA members <WSFAlist at keithlynch.net> On Fri, 23 Aug 2002 12:12:05 -0400 "Ted White" <twhite8 at cox.net> writes: > > But I wonder how amplification could > > have been accomplished in 1900, absent vacuum tubes. > > The screw may have only *diminished* the volume being transmitted > -- > not increased it. > > Well, yes. Sound moving through a passageway could be 'valved' with a screw. It is also true that a potentiometer volume control in modern sound equipment diminishes or attenuates the signal level from the full volume level, and that the throttle on a gasoline engine diminishes the power and RPM at which the engine operates, from its natural full power level. It is not that the screw valve would itself be an amplifier, but rather that the valve, and other factors, imply the existence of amplification elsewhere. Leaving aside Bellamy's speculative music machine, and looking at the real music system in Budapest, if we have a wired telephonic broadcasting system with dozens or hundreds of receivers, the electrical power of the signal needed to drive all those transducers would presumably be much greater than the signal power available from the microphone or the gramophone which is the source of the signal. That implies the need for electrical amplification, and I was wondering how they could have done that, absent vacuum tubes. > Cards with numbers on them which are punched out progressively as > things are purchased or used with the cards have been around a long > time. I seem to recall we had them for our school cafeteria when I > was a boy, more than half a century ago. > There is a British figure of speech - 'getting one's ticket punched', referring to the completion of some formal requirement which is needed to accomplish a larger goal. Ron Kean . ________________________________________________________________