Subject: DX440 mod

From: [email-masked] (Bill Kelsey)
Date: 10 Apr 93 14:18:00 GMT

From: [email-masked] (Ming Ouyang)
Date: 24 Mar 93 04:30:36 GMT

 -=> Quoting Ming Ouyang to All <=-

 MO> The Sangean ats803a has a "rec out". But on my DX440, after I removed
 MO> the little piece of plastic which covered the supposed position of the
 MO> jack, I found no jack at all. I guess I have to hardwire one. So is
 MO> there any mod plan of doing this? I'd like to use DX440 as a tuner in
 MO> a stereo system. Thanks in advance.

 MO> I am sorry if this had been asked recently. I didn't read this
 MO> newsgroup in the past few months.

 MO> -- Ming Ouyang
 MO> [email-masked]

Here is a pretty complete description of adding the DIN plug to a
DX-440, garnered from various (identified) sources.  Note that you
probably will *not* be able to use the signal from the DIN plug with
your stereo, unless your stereo accepts direct microphone input, since
the TAPE OUT on the DX-440 is intended to connect to a MIC IN jack.
You might do better to simply run a stereo patch cord from the DX-440
HEADPHONE jack to the stereo's TUNER or AUX jack.

               A GENERAL DESCRIPTION OF THE WORK

From: Michael Mitchell:
OK, Here's some stuff from the boards that I've picked up on
modifying the DX440 to have the tape-out as the radio was
originally designed before RS got their marketing guys on it.
Check out the plug in the case where the DIN connector goes.  I
have the DX440 and just installed the five pin DIN connector on
the PCB just as it must have been intended.  The only thing you
need to do is desolder the holes on the PCB and install a 5 pin
DIN PCB mounted connector.  Everything fits in place and you now
have record output.... Once I had the DIN installed and placed
the cover on, you could not tell it from a factory job...  If you
have a Radio Shack nearby, just order a PCB Mounted DIN Connector
for a Radio Shack Color Computer Cassette Interface Port.  It's
the same thing that worked for me.

The Pinouts for the DX-440 Record-Out Project.

      Locating Hole -[]
       5 N.C.  - O         O - Audio Left 6
        3 N.C.  - O       O - Audio Right 4
          Ground ---  O
                      2

This diagram is looking at the face of the receptacle after
installation.  BTW..  This makes a very tidy installation.  You
cannot even tell it was installed by anyone but the factory.  The
standard DIN connector fits up flush with the case.  Mind you
that the output is LOW LEVEL.  That is to say on the order of 15
to 20 Millivolts (.015 Volts A.C.).  One person previously was
trying to measure with a DC setting which doesn't work very well.
This connection drives a microphone input very well.  It is
independent of the volume control which is nice for late night
recording, and it will put out FM stereo when the stereo - mono
switch is set for stereo.

             A MORE DETAILED DESCRIPTION OF THE WORK

From: William N. Abbay:
Installing the DIN jack is very easy.  The PC board is already
drilled and prepared for a standard jack.  Find a PC board mount
jack, and you cannot go wrong.  I'll go through the whole
procedure, just in case you haven't had a chance to explore the
insides of your radio.

Lay the radio on its face, right side up.  From the back of your
radio, there are 6 phillips screws holding it together.  They are
approximately in this pattern:

                 o                o          o

   This one --->  o                   o      o
   is inside
   the battery
   compartment

Remove all the screws.  Remove the large D batteries, if any.
You can leave the AA batteries.

Lift the cover but be careful of the antenna wire which connects
the whip antenna to the radio PC board.  Turn the back over and
set it above the radio.

Look inside, now.  On the right side of the radio compartment,
you will see a smaller PC board mounted above the main board.
This is the audio  board.  Near the top center and lower left
corner, see the black plastic mounting clips. They support the
board.  Look closely and you will see that the board can be
lifted carefully off these clips.  Before you do this, notice the
three solder pads near the lower left side.  These contact the
three fingers sticking out of the battery compartment to provide
battery power to the radio. Those three fingers must make good
contact or the radio's computer will misbehave and act goofy.

Gently pry the clips and lift the board.  There are wires which
connect to board to the speaker.  Be careful of these.  If they
are secured with a plastic tie, cut the tie [NOT the wires. :-)]
This will give you some extra room.  If you are very careful, you
can maneuver the board over on its back and see the pattern of
holes next to the earphone jack.  These are exactly the right
pattern for a standard PC board-mount DIN jack.  Hold your jack
next to the holes and you can see which ones I mean.

At the factory, the soldering of the board probably covered these
holes.  You will have to clear them out.  From the back, using a
small, low wattage soldering iron, heat the solder around these
holes and stick a round tooth-pick through from the top.  If you
have a "solder sucker" or other de-soldering tool, the job will
be easier.  You must completely free these holes of solder.  When
this is done, you are ready to install your jack.  It can't go in
but one way.  Insert the jack and, using fresh solder, solder
each legs to its pad ... be careful and don't use too much.

Remove the plug which covers the hole in the case.

Reassembling your radio is just the reverse of the above.
Carefully line up the jacks with the holes in the case at the
same time you line up the clips which fit through the holes in
the PC board.  Snap the audio board into place.  Lift the back
over and onto the radio, taking care that you don't leave the
antenna wire sticking outside the case.  You have rock the back
slightly to get it to seat, sometimes.  Don't force anything.
The screws are all the same.

If your radio acts goofy when you are done, it is probably due to
the fact that the micro processor has not initialized properly
when you connected the case back up.  The small AA batteries
power the microprocessor when all other power is removed.  In
this case, however, you removed all power from the radio when you
disconnected the case.  Simply remove the AA batteries for a few
minutes, and reinsert.  Everything should be ok.

As to which contact goes where:  I have only identified the two
audio pins.  When I get time to run down what the others do, I
will post it to Genie.  Looking toward the jack from the outside
of the radio, the "x"s mark the audio out pins.

                   x              I connected these directly to
               x       o          the microphone input on my tape
                                  recorder and it works just
              o         o         fine as a constant level input.

                  []

Now, you can do a favor for me!  Somewhere in the process of
doing this to mine, I have disconnected a small green wire.  I
cannot find out where it goes but the radio works without it.
Right now it is just loose.  It seems to have gone somewhere on
the audio board, but I cannot be sure.  When you go inside your
radio, perhaps you can reply back as to where that little green
wire goes?

                       THE RADIO SHACK DIN PLUG

From: Fred Mckenzie:
To get the special pcb-mount 5-pin DIN connector, order from
Radio Shack a "Cassette I/O Jack" (JK4) for a TRS-80 Color
Computer model 2 or 3.  The Radio Shack part number is AJ-7356,
although the bag mine came in was marked JE-1216.  The price was
$1.00.  If they don't know already, the Radio Shack Color
Computer 3 is catalog number 26-3334.

[message continued]

... E'n la sua volontade . nostra pace. (Dante  Alighieri)
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