Table of Contents
Advertisement
1. DESCRIPTION
Where the recorder is integrated with the reproducer, as in the case
of
tape
recorders, motion picture systems etc.
,
reference recordings are taken from
the constant voltage output
of
a generator, but in the case of phonograph
testing, accurate reference disc recordings are needed.
The Gliding Frequency Recordings Type QR 2007 and 2009 are especially
designed for the purpose of frequency response investigation. They provide
-""""--
....
StlftophO!l!C
pick-up
typ•
• •
Ortafon
SPli-G
Nnl
Fjlter
I
jn"
OR 2007 bondl
... ,..,__1___:_. "'
-
5 ·7
·1962
.,.,oo
' - " " ' -
--
101
L.LA.tY;
_ _ _
,.
lOdB
~~
.
......,,...~
....
; _
,,tO
QP
1123
10
Fig. 1.2. Typical experimental result obtained by means of the set-up of Fig.
1.1. (Test of a high quality stereophonic head presenting a certain unbalance).
The total duration of one plot is 35 sec. between the instant when the pick-up
is put down on the record QR 2007 and the instant when the set-up is ready
to start a new plot.
continuous frequency sweeps from 20 Hz to 20 kHz, with lateral modulation
on the QR 2007 and left, right, lateral, vertical modulations on the QR
2009'
.
The Pickup Test Record Type QR 2008
is,
on the other hand, designed for
measurements at fixed frequencies and for tone arm resonance investigations.
It
is intended for pick-up design work, and also for general purpose checks in
combination with the gliding frequency records when curve plotting equipment
is not available.
Description of the Test Records.
General.
The B
&
K reference recordings are delivered in boxes containing five identical
vinylite records and one instruction manual (Fig. 1.3).
Both sides of each record being identical, a total of ten sides are available,
a large enough quantity to guarantee a great number of playings without
4
Advertisement
Table of Contents
