World of Ham Radio 1997/WOHR97_AmSoft_(1997-02-01).iso/mods/misc_mod/dc777.doc

Internet Message Format | 1997-02-01 | 3KB

From cbfsb!cbnews!att!linac!uwm.edu!caen!uakari.primate.wisc.edu!ames!haven.umd.edu!darwin.sura.net!jhunix.hcf.jhu.edu!sar1952 Tue Oct  6 14:55:27 EDT 1992
Article: 18214 of rec.radio.shortwave
Newsgroups: rec.radio.shortwave
Path: cbfsb!cbnews!att!linac!uwm.edu!caen!uakari.primate.wisc.edu!ames!haven.umd.edu!darwin.sura.net!jhunix.hcf.jhu.edu!sar1952
From: [e-mail] (Steven A Rubin)
Subject: Philips DC777 modification
Message-ID: <[e-mail]>
Organization: HAC - Johns Hopkins University, Baltimore
Date: Tue, 6 Oct 1992 15:27:06 GMT
Lines: 43

For those who have the Philips DC777 car radio and are aggrivated by
the fact that it's initial sensitivity is about that of a dead cow,
there is something you can do about it.  I am talking about the fact
that when you scan stations on FM it only stops at the brutally strong
ones, leaving the other weaker yet very listenable ones out in
nevernever land.

So here is what you do:

Open the top of the radio.  This is very easy as the top plate is held
on by pressure alone.  Remove the cassette mechanism, which is held
down by 3 small screws and two connecting cables to the circuit board.
Also no problem.

With the front of the radio facing you, the antenna jack should be on
the far right corner.  Just before that is an aluminum box on the
right edge of the circuit board, about 1.5" square and standing on
end.  To its immediate left you will see a chip labeled TEA6100.  Just
below that (toward the front of the radio) you will see an adjustable
coil which is in a silver box with a black slotted top.  Next to that
is a pot in a smaller silver box with an orange slotted top, and next
to it is a ceramic filter.  The adjustment is made to the orange pot
described above.

Before turning it, mark the original position of the pot so you can
put it back the way it was if things do not turn out right.  Turning
the pot clockwise gives greater and greater sensitivity.

And while you are in there, you may want to replace two ceramic
filters to get greater selectivity.  The first one is located to the
right of the above chip, between it and that 1.5" box.  The other one
is located to the left of the chip and about 1/2" toward the back of
the radio.  They consist of 3 pins, are orange, and are labeled 10.7.
Replacing these with 150Khz ones helps somewhat, but I have even
narrower 110 Khz ones on order that I will try.

The above procedures will most likely void the warranty, but will make
listening and finding stations much more enjoyable.  The above stuff
is for the FM section only.  I presume that to adjust the AM
sensitivity, one must realign something else, which I do not know.

I take no responsibility for anyone who manages to alter their radio
to the point of nonfunctionality or other degredations.