Yaesu FT-901DM Maintenance Service Manual page 69

SERVICING
MEMORY UNIT HUM, MR MODE
In some FT-901DM sets, leakage from the memory
circuitry could cause a low-level hum to be
apparent when going to the MR mode. The
following modification should eliminate this
problem.
Modification Procedure:
(1) Refer to the drawings below, and install a
two-lug terminal strip near the MR terminal
on the MEMORY UNIT.
BEFORE
Q2807
(2) Remove the white/orange wire connected to
the MR terminal, and connect it to the
ungrounded lug of the new terminal. Connect
a 1 mH mini-inductor in the collector lead of
Q2so7- This new inductor is labeled L2807
in future productions.
(3) Install a new 0.047 uF disc ceramic capactitor
between the MR terminal and ground, as
shown in the drawing. Modification is now
complete.
AFTER MODIFICATION
New terminal strip
3-14