Re: Help on Modifying the Mitsubishi DA-F10


ammonsphx
 

--- In FMtuners@..., "Aaron Auyeung" <aaronauyeung2@h...>
wrote:
I am new to the FM tuner world and as I read more about it, I got
more
fascinated by it. Recently I bought a used Mitsubishi DA-F10 and
would like
to modify it. However, there is not very much info on modifying the
DA-F10.
Can anyone give me any suggestion on how I should modify it. Also,
can
anyone help me to identify the 2 narrow filters in the attached
photo?
Thanks.
Hi- I have done a few of these units, and have one open as I write.
Filter A and B are in the narrow IF chain and are bypassed while in
the wide IF mode. In the narrow mode they feed the larger Diatone
wide filter block to the left. In stock form the A and B filters are
280 kHz parts. Going to narrower filters, or adding filters will
really help out this unit out in the narrow mode.

Filters C and D are in the strip that feeds the scope output. This
path does not carry the signal you hear.

Audio Chain:

The de-emphasis value needs to be reset to 75uS. Changing R148, and R
149 to 4.99k (1%) , and C 139, C140 to 0.015 uF will brighten up this
unit.

Change C401 and C501 to 10 uF. Change C402 and C502 to 22uF. Change
C403 and C503 to 10 uF. Change C404 and C504 to 22 uF.

Change C130 to 470 uF.

It's a great sounding unit when it's cleaned up a bit.

Bill Ammons
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