IX2-700 Dual Intracellular Preamplifier
6
EXTERNAL I BNC
The External I BNC allows for externally generated step commands at
20nA/V times the headstage multiplier.
1/3/5/10/30 KHZ WB FILTER SWITCH
The low pass filter limits the high frequency response of the amplifier to
minimize noise. The bandwidth should be set to the lowest setting, which will not
distort the desired input signal. The Wide Band WB position removes the filter and
leaves the amplifier with as wide as possible frequency response. The filter switch
only affects the 10 Vm and 100 Vm connector.
CLEAR SWITCH
The Clear Switch can be used to clear blocked microelectrode tips by
passing a large current through the recording electrode. It is also useful or impaling
cells, and typically, the Clear positive will be (100nA X N) the most common
polarity, although negative currents are also available. In addition, the Buzz Switch
is many times useful for clearing a blocked microelectrode and impaling cells.
MONITOR (MON) BNC CONNECTOR
Actual currents being passed through the microelectrode are monitored and
available at the I MON connector. Sensitivity is +10 mV per nA divided by the
headstage multiplier. Thus, for the X.I probe sensitivity is 100 mV per nA. The
usable dynamic range of the I MON connector is +12V. The I MON connector is
unfiltered. Output impedance is 600 ohms.
10 Vm and 100 Vm Output BNC CONNECTORS
These outputs of the voltage recording amplifier scaled up by +10 and +100.
This output is processed by the filter switch and has added to it the Offset voltage.
The output impedance is 600 Ohms and the range is + 12 volts.
IG CALIBRATION
The headstage bias current can be adjusted by shorting the headstage Input
to ground (headstage rod) and setting 10 Vm output to zero using the OFFSET
Control. Then put a 10 to 100 megohm resistor from the headstage input to ground
and then use a small screwdriver or trimpot adjustor for 10 Vm equal zero.
