This is a check (or adjustment if necessary) where you need to understand what you are doing.

Let us discuss the "problem" step by step.
The example is based on a 2-track recording, as you have seen on a previous page.

An Azimuth problem is shown below, but to understand why it is a problem we have to look at this in detail...


Above is the track again, and a head. A recording or playback head has a very narrow gap where the actual recording/playback takes place.
 

The picture above shows a tone recorded on both tracks ( on a test tape for example).
If the head has correct azimuth, the sine wave will reach the head gap at the same time on both channels.

But, if the azimuth is incorrect (see right part of picture), the tone will be in opposite phase on the channels.
This will result in the signals "killing each other" as they are 180 degrees wrong.
To the left you see a correct azimuth where signals reach the head gap at the same time.

The tape has several frequencies for setting the azimuth. It starts with a low frequency for "coarse" settings, and then higher
for "fine" adjustments. If one would only have a high frequency, the signal could be 360 degrees out of phase and it would still look "ok" on the oscilloscope. Let me know if I am not able to explain it here. Then I can add some more pictures.

The photo above is from a measurement on a Tascam 52.

The measurement is done by connecting 2 channels from the recorder to an oscilloscope.
If the recorder has more than 2 channels, the outmost tracks are measured. (1 and 8 on an 8 track recorder).

This is actually a photo from the same measurement. The only difference is that the oscilloscope is in another "mode"
which will present this picture. This is the picture you often see in service manuals.
I prefer to use the other mode, where one can see the sine waves. I find it easier to understand.
 
 
 

OTARO MX 5050 models

Back to  Checks, adjustments...