6
7
Hybrid Null Adjust (optional)
The null adjustment allows you to manually optimize the
relationship between the hybrid in your telephone and the hybrid
in the TAP-1. In most applications, this can be left at the factory
setting, or set once and then left alone. If however you are
concerned with transmit / receive isolation then you should follow
this procedure:
1)
With a telephone connected and in the off-hook position,
play a sine wave, noise source, or other suitable signal into
the TAP-1 line input jack. Be sure to cover the microphone
of the handset to prevent the acoustical signal from
traveling from the receiver to the microphone.
2)
Observe the signal on the output jack of the TAP-1 using a
meter, oscilloscope, or amplifier and speaker.
3)
Adjust the null control to find the minimum (the point
where the signal bottoms out, or is reduced to near
zero).
The null adjust is a ten-turn control. Keep turning
in one
direction or another to find the null or until you hear or feel a
click. The click means you are at the end
of travel and
you must reverse directions.
Specifications
Electrical:
RJ-11
AC Impedance:
510 ohms
DC series resistance:
480 ohms
DC Voltage:
-48VDC (open circuit)
DC Current Max:
70 mA (short circuit)
Trans-Hybrid Loss:
> 50 dB at 1 kHz
Hybrid Null Adjust:
Rear panel recessed control.
Input
Connector:
Gold plated RCA jack.
Impedance:
600 ohms
Level:
Rear panel recessed control.
Bandwidth:
60 Hz - 15 kHz (+- 3 dB)
120 Hz - 8 kHz (+- 1 dB)
Output
Connector:
Gold plated RCA jack.
Impedance:
600 ohms
Level:
Rear panel recessed control.
Bandwidth:
180 Hz - 12 kHz (+- 3 dB)
300 Hz - 6 kHz (+- 1 dB)
Physical:
Housing:
ABS Plastic
Size:
1.6" high x 5.1" wide x 5.2" deep
Weight:
1 pound
Power:
18 VAC, 160 mA
(120 VAC, UL approved
transformer)
