[Premium-Rx] WJ URR-74 (WJ-8718A) issue

[fintronics .]

Hi Les;

Those pins that the battery module was plugged into were all very corroded.
I had to remove and toss them. Since the battery isn't essential to the
operaion of the receiver, I'll put that part of it on hold for now. I'll
probably use a couple of NIMH cells in some sort of holder.

I'll try cleaning all the edge connector card contacts today as you
suggested...

Thanks.

Glenn


On Sat, Feb 11, 2017 at 1:54 PM, <lrlayton at cox.net> wrote:

> As another member pointed out the battery is for storing frequency
> information when the receiver is powered down. The correct replacement is a
> Varta 2.4 volt mempac part number 55615 702 012. These are available from
> many sources. In my very similar WJ-8716, the battery plugs into pins that
> are soldered to the board and is easily removable.  As for the other
> problem I would start by removing the plug-in boards one at a time and
> cleaning  the contacts with de-oxit or some other contact cleaner if you
> have not already done so.
>
> Les Layton
>
>
> ---- "fintronics ." <fintronicsusa at gmail.com> wrote:
> > Reveived my  URR-74 last night.. what a beautiful receiver!. Just about
> > mint condition, incredible internal construction... While inspecting the
> > inside, I noticed one of those nicad battery modules soldered on to one
> of
> > the plug-in PCB's. The 4 pins were green with corrosion as were the pads
> on
> > the solder side of the board. Quite the pain in the butt to remove and I
> > spent quite a bit of time cleaning up the mess on both sides of the board
> > but now the battery module is removed and the board is cleaned up with no
> > open or corroded traces.
> >
> > Since this receiver has no microprocessor, I'm wondering what the heck a
> > battery backup/module would be used for? There are no memories, etc...
> > Figured I'd power it up without a battery and see what happens.
> >
> > So on to powering it up....It didn't come with a power cord so I powered
> it
> > up with a line cord/alligator clips to that 3 pin rear panel connector.
> > Headphones, outside wire antenna... fired it up... It's working! ....
> > Switches and pots are very dirty but I'm hearing signals, all modes, all
> > filter positions working... but then.....
> >
> > I noticed the strangest thing while tuning across some SW and AM BCB
> > signals. While tuned to an AM BCB station on 840khz, I noticed what
> appears
> > to be an image of that signal exactly 20khz down from 840khz.... and
> here's
> > where it gets strange... While tuned to the image signal at exactly
> 820khz,
> > if the tuning is moved even 10hz above 820khz the image signal
> disappears!
> > completely!.... but if tuned at or below the image at 820khz, the signal
> is
> > there, as if only receiving one sideband of the AM signal... This happens
> > on all AM signals regardless of band or frequency....
> >
> > What the heck?... could this be related to the missing battery?
> (doubtful),
> > .... I did notice when I had the receiver open that some of the SMA coax
> > interconnect cables were loose... ... maybe this is a problem with
> > frequency data to the synth getting corrupted?.... don't know...
> >
> > Any ideas? where to start looking?.
> >
> > Thanks...
> >
> > Glenn
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