[Tandy] Odyssey of a Realistic DX-392 receiver.

[Phil Atchley]

Hi.
Hi.
Earlier I posted a request for service information on a DX-392/ATS818CS.
Well, in the meantime I decided to go ahead and see what I could do for =
the
poor thing without service information.  I repair stereos on commission =
in a
local TV shop and I had already repaired the audio section.

The history:
The set came to me as a "gift".  It had been to a service shop for a =
repair
estimate, having taken a "Voltage surge".  The customer decided not to
repair it and gave it to me.  When it arrived it "rattled" and the =
capstan
pressure roller flopped loosely.  It had no audio in the speaker, though =
the
tuning meter showed activity when tuning.  It had been estimated as =
needing
an audio IC and plastic trimmer capacitors (?).  A check with a headset
showed weak/distorted audio in one channel.

The repairs:
First, I shook the "rattles" out of the set.  These proved to be the =
audio
output IC for the speaker channel and a "BIG" chunk broken off the =
corner of
the circuit board by the tuning control.  Luckily the latter contained =
no
traces, just a shield groundplane!

The next step.  I removed the headset only output IC and installed it =
where
the former "tech" (?) had removed the IC that drives the speaker.  I =
then
had weak/distorted audio in the speaker.

Further examination showed that there was a shorted transistor in the =
audio
section.  Without a schematic I'm not sure of its function but I =
installed a
suitable sub from the junkbox.  On a whim I re-installed the "rattle", =
the
IC the "tech" had removed and checked the radio.  Eureka!  Both channels =
now
played with good audio (headset), good audio in the speaker.

Next I tackled the cassette mechanism.  Upon removal of the mechanism =
from
the deck my first thought was that it had lost a "clip and spring" =
allowing
it to flop loosely.  Closer examination showed that it had come =
unclipped
from a little locking finger, allowing it to get out of position.  I
re-installed it properly and the cassette unit is now fine!  I can't see =
any
reason that the last problem should have occurred.  When it went in the =
shop
the cassette player was supposed to be fine, just no audio for any =
function
(per the owner).  When I checked it the only plausible reason I can =
figure
that the finger could have come unclipped would be to stress it while
removing the mechanism from the case.  No need to do that to repair the
circuit board electronics.=20

The moral of the story?  Just because a shop says that an item has =
certain
parts bad doesn't mean it's necessarily so!  For a couple hours of work =
and
no cash expenditure I now have a very nice portable digital shortwave
receiver with recorder to augment my SWL shack.

 73 de Phil, KO6BB

****************************************************
*  DXing THE WORLD WITH THE FOLLOWING EQUIPMENT.   *
*  RECEIVERS:                                      *
*    HAMMARLUND SP-600JX17 Surplus receiver with   *
*               HAMMARLUND HC-10 Sideband adapter. *
*    YAESU VR-5000 Wideband, REALISTIC DX-392.     *
*    Homebrew Longwave "Hybrid" CW receiver.       *
*    Others that pass thru or are waiting repair.  *
*  ANTENNAS:                                       *
*    Coil Loaded 18.5 Meter Long Sloper.           *
*    Roof mounted Hustler 6BTV 6 band Vertical.    *
*    Scantenna Scanner antenna at 7 Meters high.   *
*  LOCATION: Merced, Central California.           *
****************************************************




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