Heathkit SB-10 Series Troubleshooting Manual page 46

AF Gain control set to a comfortable listening level
AC Voltmeter connected to top of AF Gain control
Band Switch set to 3.5 (80 meters)
Frequency dial set to 3700 KHz.
Disable the AVC by Disconnect the two yellow wires from pad 13 on the IF board
(rear left as viewed from the bottom of the chassis) and connect them to ground with
a jumper wire.
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Note 1: The 1 RX Mixer tube may develop a small negative grid leak bias between
0 VDC and -0.5 VDC (as measured at V11 pin 1). This should have minimal effect
on the measurement.
Note 2: Don't forget to restore the AVC wiring upon completion of the measurement
process.
All signal levels are specified in dB relative to 1 milliwatt as measured into a 50 load
(dBm). If preferred, this can be converted into microvolts using Table 3. dBm to
Microvolt Conversion Chart on page 45.
Signal Level Measurements Page 46