Models 2107 & 2117 Operation • 7
Using the Photoreceiver
1. Mount the photoreceiver. Use the 8-32 thread
(M4 for metric versions) on the bottom of the
casing to mount the photoreceiver to a post or
pedestal.
2. Supply power. Power the Model 21X7 using
either two 9-volt alkaline batteries or a ±15-V low-
noise linear power supply (such as the Newport
Model 0901).
3. Connect the receiver output. Connect your
voltmeter, oscilloscope, or other instrument to the
Output SMA connector on the receiver.
If you wish to connect to a BNC cable, you can
purchase a BNC-to-SMA adapter such as the
Newport Model 1225.
4. Turn on the photoreceiver power. For external
power, use ±15 VDC ON; for battery, use Batt
Mode ON.
5. Align optical beams onto the detectors.
The photodiodes are not very large, so take care
when aligning each beam.
6. Adjust the gain. Use the knob and rocker switch
on the receiver to set the gain. The bandwidths
vary with the gain setting (see table on page 10).
7. Adjust the filters. Select low-pass and high-pass
corner frequencies using the knobs on the receiver.
8. Balance the optical input levels. Alternately block
each diode and observe the signal strength. When
they are approximately equal and opposite, adjust
their relative intensity until the balanced output is
zero volts.
9. Turn off the photoreceiver power. When you are
finished with the receiver, place the power switch
in the ±15 VDC ON position and switch off or
unplug the external power supply.
Note:
Note:
21x7 10MHz Adj Blncd Rcvr revA.fm Page 7 Friday, January 7, 2005 12:22 PM
