I. Preparing the Board for DC Operation
The receiver of the RadioProcessor is capacitively coupled, leading to attenuation at
low frequencies. To operate at low frequencies, it is necessary to remove the capacitor (C680)
at the input of the RadioProcessor. Illustration 1 below shows the location of C680.
NOTE:
Removing the capacitor at C680 will introduce a DC offset in measured values when
the receiver is loaded. See the section below on handling the DC offset.
To prepare the board for DC operation, please follow the following steps:
1. Carefully remove capacitor C680 from the receiver of the RadioProcessor (see
Illustration 1 above for the location of C680.)
2. Connect the pads at C680 using either a small piece of wire or solder.
3. Verify continuity between R603 and connection created in step 2.
4. Verify that there is no short between C680 and C605.
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2010-01-29
4
Illustration 1:
Location of C680
