Table of Contents
Advertisement
1. DESCRIPTION
Recording Characteristics.
Pick-ups should be tested with reference to the internationally recognized
characteristics
if
they
are
intended to
give constant
output
as
a function of
frequency. Gliding frequency records
should
in
general
be cut according to
the recording characteristics
shown
in Fig. 1.10-bottom. In the case of the
B
&
K Gliding Frequency Records,
a characteristic as shown
on top of Fig. 1.10,
which
is
converted by
an equalizing
filter in the measuring chain to the
appropriate characteristics has been
adopted.
The
reason
for the high fre-
quency level limitation on the record is that if true reproduction is intended,
the radius of curvature of the modulated
groove
wall
must
remain
appreciably
larger than the
stylus
tip radius.
The wave-length being determined by the chosen
groove
speed, and the stylus
tip radius being normalized to 15-18
f.1,
for stereophonic pick-ups, this sets a
db
:::
0
·g
~
i
-10
~
-20
20
+20
db
+10
IIIII
I
I
I
I
I
Hitlf11
11
1
/
Recording Characteristic
v
Gliding Frequency Reco
1
rds Cl.R
2007
& Cl.R
2009
__
....
IIIII I
I
I II
II
II
50
100
200
500
1000
2 000
10000 20000
--
Type
4409
Equilizing Filters Characteristics
[/
llN
Filter Switch
pos.:
I.E.C.
Curve
2,
•
•
"
: I.E.C.
Curve 3
/
II I
r>-
>"
Fi~te~ s
1
w~t~~ p~s.:
Lin.
...,_.;:-:::::;.::::
_,
I
Ill
I
20
50
100
200
500
1 000
2 000
10000 20000
b
+20
+10
~
>
0
...,
...,
~-1
0
-20
r--
20
IIIII
Total Characteristics
I
-
(Types tl.R
2007109+4409)
111111
I
I
I
Filter Switch
pos.:
L~n
.
.\
v
/
1-"
50
100
200
)/
,/
/
;
:::.;:;--·
I
f"'
I
Fi
lter Switch
pos.:
I.E.C.
Curve~j_t--
•
..
•
:
I.E.C. Curve3
IIIII
I
I
I
I
I
IIIII
II
II
II
II
500
1000
2000
II
Ill
II
Ill
10000 20000
~6232
tl
Fig. 1.10. Recording characteristics available when using the Gliding Frequency
Recordings in connection with the Response Test Unit Type 4409. The curve
no. 3 is specified by the International Electrotechnical Commission in its
publication no. 98-1 for stereophonic recordings.
9
Advertisement
Table of Contents
