[Vintage-Audio] Re Teac FM Copy

Tue Jun 18 22:04:01 2002

Bob and group,

Yes, I'm beginning to remember more.
It's true we didn't want this interactiom. And, I do recall the problem.

But, *why* would Duane's "FM copy" switch *increase* the hi-freq
content?
This one I can't quite get a handle on!

Allen

"Robert J. McKee" wrote:

> Sorry, no better ideas, but one of the functions of the high
> filter
> for recording FM MPX broadcasts was to prevent interaction of
> the 19 KHz with the AC bias frequency producing audible beats.
> Bob (new to your list) McKee
>
> ----- Original Message -----
> From: Allen, KJ6XH <[email protected]>
> To: <[email protected]>
> Sent: Tuesday, June 18, 2002 9:07 PM
> Subject: Re: [Vintage-Audio] Re Teac FM Copy
>
> > Hello Duane,
> >
> > It's been a long time. But, I have a couple of leads you
> could check out.
> > 1.   The "vintage" stereo receivers had a filter to minimize
> the 19KHc
> > Pilot tone (that tells the receiver "this is a stereo
> signal- not mono.
> > The recorder switch brings-in a hi-enphasis network to
> restore some
> > of those lost highs.
> >
> > 2.   FM circuitry includes a pre (post?) emphasis circuit to
> keep overall
> > freq response in proper perspective.on the receiving end.
> > *If* the recorder output is tapped-off prior to this
> network,  the
> > recorder would nead this provision to make-up for the
> "missing" network
> > that is in the receiver.
> >
> > 3.  As I recall, FM freq response was normally limited to
> 15KJHz on the
> > hi end.  Perhaps the switch allows you to get some of the
> "shimmer" of
> > the hi's above this point.
> >
> > I, myself, tend to believe the third possibility  more than
> the first two.
> > But, Maybe these give you something to think about and
> experiment with.
> > Remember-- Most natural sound is what counts, not
> necessarult the nrightest!
> >
> > Any one have better ideas?
> >
> > Allen
> >
> >
> >
> > "Duane Fischer, W8DBF" wrote:
> >
> > >
> > >
> > > The Teac model A-5500 has a switch marked: FM Copy on/off.
> What is its intended
> > > purpose? I noticed while listening to a vinyl recording
> being sent through the
> > > source in monitor mode that having this switch turned on
> increased the highs. I
> > > though this curious. What is the real deal?
> > >
> > > Thanks.
> > >
> > > Duane Fischer, W8DBF
> > > [email protected]
> > >
> > > _______________________________________________
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> > > List Administrator: Duane Fischer, W8DBF
> > > ** For Assistance: [email protected] **
> >
> > --
> > 73 de Rev. Allen, KJ6XH      Real Radios glow in the dark!
> >         http://home.earthlink.net/~mattall
> >
> >        Checkout TBN on DirecTV Satellite-- channel 372
> >             and Cable Systems all around the USA
> >
> >
> > _______________________________________________
> > Home: http://mailman.qth.net/mailman/listinfo/vintage-audio
> > List Administrator: Duane Fischer, W8DBF
> > ** For Assistance: [email protected] **
>
> _______________________________________________
> Home: http://mailman.qth.net/mailman/listinfo/vintage-audio
> List Administrator: Duane Fischer, W8DBF
> ** For Assistance: [email protected] **

--
73 de Rev. Allen, KJ6XH      Real Radios glow in the dark!
        http://home.earthlink.net/~mattall

       Checkout TBN on DirecTV Satellite-- channel 372
            and Cable Systems all around the USA