Beeps. In 1927. What made them?

[Fletch]

Victor Record no. 20606 usually contained 2 sides of the William Tell Overture by the Victor Symphony.
However, this gent picked up a copy with what he calls a "test frequency test pressing" on side B.
[video=youtube;_84oQWgyvcQ]http://www.youtube.com/watch?v=_84oQWgyvcQ[/video]

It got me wondering what sort of apparatus the Victor Co. might have had access to at that time to create steady, accurate frequency beeps. They sound electrically amplified, if not fully electronic. There are even clicks, which might be a generator switching on and off or might just be pops in the shellac.

I'd ask the poster, but he won't take comments. Anyone have any insights into this?

 

[dhermann1]

Wait, slow it down to about one tenth speed. You'll distinctly hear, "Paul is dead, Paul is dead."

 

[Fletch]

I was afraid of that.

 

[vitanola]

Well Western Electric helped The Victor produce these records, using the same technology that was used to produce the frequency test records that were used at 463 West Street during the development of the Orthophonic Process. The Audio Frequency oscillators used at the time were of the General Radio pattern, where 2 radio frequency signals would be mixed to produce an audio frequency beat. These units were in general use in electro-acoustic laboratories in the years before the introduction of the Hewlett-Packard 200A, but were rather troublesome, as they were difficult to keep in calibration, and requred quite a bit of "tweaking" to assure a pure sine wave output.

 

[Dixon Cannon]

Wait, slow it down to about one tenth speed. You'll distinctly hear, "Paul is dead, Paul is dead."

Haaaa!...that is funny! Good one! -dixon cannon

 

[Fletch]

Well Western Electric helped The Victor produce these records, using the same technology that was used to produce the frequency test records that were used at 463 West Street during the development of the Orthophonic Process. The Audio Frequency oscillators used at the time were of the General Radio pattern, where 2 radio frequency signals would be mixed to produce an audio frequency beat. These units were quite general, but we're difficult to keep in calibration.

Thanks, this helps. Why I didn't think of oscillators, I don't know.

 

[majormajor]

Haaaa!...that is funny! Good one! -dixon cannon

+1