BRUEL & KJAER 2305 - Input Transformer Type TI 0001

Frequency
CharaeterisHe:
Equalizing Filters
Linear, 20-20000 Hz (cIs).
curve 2} .
of I.E.C. Recommendations 98 and 98·1
curve 3
All
three characteristics are obtained only from a
combination of the filters and the B & K Mono·
phonic or Stereophonic Gliding Frequency Records
Type QR 2007 or QR 2009.
Total Accuracy: ± 1 dB from 20 Hz (cIs) to 16 kHz
(kc/s).
Input Transformer Type TI 0001.
By connecting this Transformer to the INPUT of the Recorder a symmetrical
input with respect to ground is obtained. The Transformer has two input
impedances which are selected by a switch INPUT IMP. The two im·
pedances are 20 k..Q and 600 D. A third position of the switch allows a
grounded middle point of the INPUT to be utilized. Vide Fig . 4.11.
Fig. 4.10. Input Transformer T1 0001.
To give a linear frequency response, 10-20000 Hz (c/s) ± 0.2 dB, the OUT·
PUT of the Transformer should be prop e rly loaded . First, to ensure that a
low capacity is connected to the OUTPUT of the Transformer the special low·
ca pacity cable AO 0018 delivered with the Transformer should always be
used when connecting to the Level Recorder. Secondly, to ensure the proper
resistive load, the toggle switch on the Transformer should be set in position
"Ext. Load".
Great efforts are made to make the Transformer insensitive to externally
inductive stray fields. Therefore the Transformer has been furnished with
a double mumetal screen . Due to this, the sensitivity to a field of 50 Hz (cIs)
a nd 50 gauss corresponds to only 0.6 mV approx. on the OUTPUT terminal
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