Re: [ARSCLIST] Little azimuth trick

[George Brock-Nannestad <pattac@xxxxxxxx>]

From: Patent Tactics, George Brock-Nannestad

Hello,

Chris @Eugene wrote

> Hi,
>    The normal correct procedure, according to service
> manuals, is to adjust for maximum signal strength,
> before "fine-tuning" with a Lissajous pattern for
> phase relationship. It is possible to get the
> correct Lissajous pattern at less than maximum
> signal strength azimuth adjustment.
>    Usually what I do is watch the signal strength
> on an audio voltmeter or the o'scilloscope. Adjust
> for maximum amplitude, then you can "tweak" it
> very, very slightly for the proper Lissajous
> pattern.
>    Hope this helps.
>
> Chris
> @eugene-audio

----- this is what we all do. However, Richard took the signals from the
"edge" tracks (i.e. those almost ½ inch apart), realizing that the 1 kHz
signals (a _low_ frequency) were in phase in all channels, and generated the
Lissajous from these. This is a good (and novel) way to obtain precision. The
need for obtaining a maximum amplitude reading does not arise at this low
frequency - you cannot tilt the head so much that you get an erroneous
"lower" maximum at this frequency, unless it is a monitoring tape at very,
very low speed.

Thank you, Richard, for this neat trick!

Kind regards,


George


>
>
> --- "Richard L. Hess" <ArcLists@xxxxxxxxxxxxxxx>
> wrote:
>
> > Hi, all,
> >
> > Last night I was transferring a 4-track, 1/2" tape
> > and it only had
> > 1kHz tones at the head and the azimuth didn't sound
> > right. It
> > appeared the tones were recorded as part of the same
> > session and not
> > an add on. But there were no HF tones.
> >
> > I used the two outer tracks and fed that into the
> > vector display
> > software and it was pretty easy and definitive to
> > get a null in the
> > Lissajous figure.
> >
> > Just thought I'd pass it along FWIW in case you
> > already weren't doing
> > this type of thing. Remember, azimuth errors can't
> > really be fixed in post.
> >
> > Cheers,
> >
> > Richard
> >
> > Richard L. Hess                           email:
> > richard@xxxxxxxxxxxxxxx
> > Vignettes
> > Media                           web:
> > http://www.richardhess.com/tape/
> > Aurora, Ontario, Canada             (905) 713 6733
> >   1-877-TAPE-FIX
> > Detailed contact information:
> > http://www.richardhess.com/tape/contact.htm
> >