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Path: utzoo!watmath!clyde!burl!ulysses!mhuxj!mhuxn!houxm!ihnp4!zehntel!hplabs!hao!noao!terak!doug
From: doug@terak.UUCP (Doug Pardee)
Newsgroups: net.analog,net.audio
Subject: Re: Frequency Shifter with no practical application makes funny noises!
Message-ID: <209@terak.UUCP>
Date: Mon, 3-Dec-84 19:11:06 EST
Article-I.D.: terak.209
Posted: Mon Dec  3 19:11:06 1984
Date-Received: Thu, 6-Dec-84 05:45:07 EST
References: <49@vax2.fluke.UUCP>
Distribution: net
Organization: Terak Corporation, Scottsdale, AZ, USA
Lines: 24
Xref: watmath net.analog:100 net.audio:3645

> 	Hey...remember that article in EDN of October, 1982 about the audio
> 	frequency shifter?  I built one.
>
> 	Now, if somebody could just tell me what I can use this thing for...

Sell it to local ham radio operators who operate Single Side-band (SSB)
using transceivers without Receiver Incremental Tuning.  Somewhere over
99% (no joshing) of all SSB operators mis-tune when listening, always
in such a manner that the received voice sounds higher-pitched than it
really is, usually by 50-100 Hz or so.  When two hams are communicating
and neither has RIT, there is inevitably a waltz whereby ham B tunes
in ham A's voice a bit high-pitched, then when ham B is talking ham A
tunes him in a bit high-pitched, etc. and they slowly walk up the band.
(With a transceiver without RIT, changing the received frequency also
changes the transmitted frequency).

With the shifter, a ham can transmit his voice shifted high enough that
the other ham will tune properly.  Or even better, the other ham will
tune so that HIS voice sounds higher-pitched to the ham with the
shifter!  Of course, a more direct but less interesting approach would
be to simply use the shifter as if it was an RIT, shifting the
incoming voice up to the desired pitch.

Doug Pardee -- Terak Corp. -- !{hao,ihnp4,decvax}!noao!terak!doug