Networks > Audio Attenuators
Precision Networks
Shallco offers two classes of attenuation networks:
- The 600 Series for general use audio measurements (20-20,000 Hz) when high extreme accuracy is not required. These units provide plug-in impedance matching network options and are economically priced for small labs and broadcast use.
- The 700 Series provides high accuracy over a broad frequency range up to 500 kHz and is usable to 10 mHz for losses less than 50 dB.Power Input: 28dBm (0.6 watt)
Terminals: 5-way Binding Posts
| Portable |
Rack Mt. |
Impedance |
Circuit |
Range |
Accuracy* |
| T-690 |
T-690R |
600 ohms |
Bridged-T |
0-110 dB, 1 dB steps |
+/-(2%+0.05dB) |
| T-693 |
T-693R |
600 ohms |
Bridged-T |
0-111 dB, 0.1 dB steps |
+/-(2%+0.05dB) |
| T-790 |
T-790R |
600 ohms |
Straight-T |
0-110 dB, 1 dB steps |
+/-(0.5%+0.03dB) |
| T-795 |
T-795R |
600 ohms |
Straight-T |
0-111 dB, 0.1 dB steps |
+/-(0.5%+0.03dB) |
*Accuracy of the setting
Fixed Attenuator Pads
| Impedance in Ohms |
Min. Loss in dB |
Max. Loss in dB Available by Type |
| Input |
Output |
|
T-154 |
T-950 |
H-154 |
H-950 |
| 30 |
600 |
18.92 |
100 |
65 |
60 |
60 |
| 50 |
600 |
16.63 |
100 |
70 |
60 |
60 |
| 150 |
600 |
11.44 |
100 |
75 |
65 |
65 |
| 600 |
600 |
0 |
100 |
80 |
75 |
75 |
| 600 |
30 |
18.92 |
100 |
65 |
60 |
60 |
| 600 |
50 |
16.63 |
100 |
70 |
60 |
60 |
| 600 |
150 |
11.44 |
100 |
75 |
65 |
65 |
Note:
1. Observe the minimum and maximum loss limits indicated above when specifying loss.
2. It is necessary to make an external connection between the two "C" terminals on the H-950 type.
3. Resistor accuracy is +/- 1% and continuous power rating is 0.6 watt
Tapped Fixed Attenuator Pads
| Type |
Circuit |
Range in dB |
Description |
| 1030-G* |
"T" |
0-40 dB, 1 dB steps |
1, 2, 3, 4, 10 & 20 dB pads |
| 1230-G* |
"H" |
0-40 dB, 1 dB steps |
1, 2, 3, 4, 10 & 20 dB pads |
| 1031 |
"T" |
+4 to +24 VU, 1 VU steps |
3600 ohm resistor & 3900/3900 VU pads |
*standard impedance is 600 ohms, resistor accuracy is +/- 1% and continuous power rating is 0.6 watt
Branching Networks
Series 1130 branching networks may be obtained in single input/multiple output and multiple input/single output circuits for both balanced and unbalanced lines ("H" or "T"). Loss for a 1x2 or 2x1 is 6 dB; 1x3 or 3x1, 9.5 dB; 1x4 or 4x1, 12 dB. Our staff can assist with formulating the part number for specific applications.
Calibration Services
Shallco is equipped to provide accurate readings up to 100 dB at a frequency of 1000 Hz traceable to NIST. Our ratio standard is accurate to ± .005 dB. Certification accuracy is within ±(0.5% +0.03dB) of the setting over the range of 0.1 dB to 100 dB when measured at 1000 Hz and 600 ohms impedance. Readings at higher frequencies can be supplied with decreased accuracy. Please consult our customer service department for complete details of our test procedures. We can provide either of two certifications: an overall accuracy statement or incremental accuracy with readings of each decade step. Copies of test procedures are available on request.
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