DX 392 problem

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Haley

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Has anyone ever had this problem? The radio works fine off of AC. I have replaced the batteries, both sets. The 3AA backups, and the 4D cells. I have hit the reset button. I have done this several times brand new, tested batteries they are fine. Yet no matter what, when I go through the steps, according to the manual (which I have)---the large E flashes. Which means the back up batteries need replaced.

I opened up the case this morning (I am not much of an electrician) , everything seemed solid, no loose connections. I always liked this radio for its decent speaker, and use it off AC. But , its a portable radio and kind of defeats the purpose. Anybody have any ideas??? Thanks, Mike
 

Haley

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Ok , I need to apologize, I did a search of my posts, and nothing came up for the DX 392. But , I guess I posted a similar question 5+ years ago. But, Im still open to any suggestions. Mike
 

Boombox

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Try hitting the battery connector with some solder, where it attaches to the board.

Suggestion #2, hard wire the battery to the PCB, with hookup wire. The DX-390 (and probably the 392 -- I only have a 390) use these metallic 'fingers' to transfer the juice from the batteries to the PCB. Those metallic fingers can oxidise, solder pads beneath them can wear from years of vibration, oxidise, etc.

So try adding solder to the two pads, or just hardwire the fingers to them with some long hanks of flexible wire.

While you're at it you could add a couple back to back diodes between the antenna post and the battery ground, it will save your RF amp transistor from being zapped. There was more than enough room in my 390 to add a couple back to back diodes and shove them in the corner of the back of the radio.

Hope this helps.
 

Haley

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Thanks for those suggestions-----I haven't seen those anywhere on the internet. I will give them a try! Not sure how people feel about the 390/392s , but I always thought they sounded great (speaker wise). Thanks again, Mike
 

Boombox

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DX-390's and 392's seem to get a mixed rep. People either think they're great portable SW radios, or think they're junk.

A lot of the 'junk' ones could be due to the RF amp on some of them getting fried. The RF amp on the radios is an FET and there isn't much to protect it from getting zapped. I wired in the back to back diodes on mine in 2005.

If you're in a high signal environment 390's and 392's can overload. I noticed it when I took my 390 to Louisiana in the late 1990's. Overloaded on 20 meters with just 20 ft. of wire connected to the ext. antenna jack. When I just used the whip, it was loaded with signals, with no overloading.

Here where I live it's a relatively low signal environment, and I only get images on rare occasions. I've even used a 100 ft. wire with mine before and didn't have problems.

You're right about them sounding good. My 390 sounds great on speaker or headphones. I like it a little better than my DX-398, sound wise. The 398 can sound a bit trebly on SSB signals.

My DX-390 is the SW radio I still use the most, because of its sound and its ease of use. My DX-398, which has an extra IF stage, will pull in the SSB a bit more clearly, but the 390 will usually hear anything the 398 hears. The 398 has USB and LSB, where the 390 has a BFO.

I usually keep the tuner at 1 khz on my 390, and use the up and down buttons for tuning in 5 khz increments.

The batteries in the 390 last a long, long time. It's a very handy radio.

I hope you're able to fix the issue with your DX-392.
 

Haley

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Thats funny, a lot of the points you made, I could have written! I also use a 398----16 years old, and still working fine, but as you said, a bit too much treble. Like you also , I always have those two radios set to 1 khz, and use the buttons.

Overload on both of those radios is not got good in most of my house , but once I get them outside-----they really pick up the signals. Thats the reason for me trying to fix the 392------they do not do well with wall plugs. Anyway thanks for the help, and (common) perspective. Still working on it! Mike
 

AB4BF

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My 390 is several years old and I replace the batteries at 6 month intervals. I make a date stamp with either a wire marking printer or a brother P-touch. Even though I try to use the "best" cells, they still seem to leak in my 390. I have found that after removing all power, I take Dollar General window cleaner and spray the affected terminals and let them soak for a while and it usually removes most if not all corrosion. You may have to repeat once or twice to get it nice and shiny. If the corrosion has eaten into the metal causing pits and such, I'll clean it up with a fine emery board and put a coat of pure tin solder on it.

Be sure to dry the unit before powering back up. I use compressed air.

I have used this same cleaning procedure on other electronic devices and had good results.

Recently, I was listening to the 390 and when I flipped the BFO on, I lost all AM, I guess it was the little transistor that goes. FM still plays good. I would fix it, but My eyesight isn't that good any more.
 

Boombox

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Barry08,
What exactly happened when you switched the BFO back to AM? Is the BFO stuck on? Or did reception on all the AM bands disappear? Just curious, I haven't heard of this issue before.
 

AB4BF

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Barry08,
What exactly happened when you switched the BFO back to AM? Is the BFO stuck on? Or did reception on all the AM bands disappear? Just curious, I haven't heard of this issue before.
If I flip the BFO on or off, I have no AM of any kind. Don't know what happened. I tried it several times since then and still no AM.
 

Boombox

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If I flip the BFO on or off, I have no AM of any kind. Don't know what happened. I tried it several times since then and still no AM.
I looked over the block diagram and schematic, and because it's all diode switching, I can't see where the switch is on the schematic (maybe it's there and I'm just not seeing it). So I don't know if possibly your switch gave out or weakened the connection to the solder pads from use, or it would be some other problem. I'm just not savvy enough to figure out what your problem may be..

On some radios, a front mounted switch will do similar things (GE Superadio 1's and 2's are apparently famous for a front mounted switch weakening the connection to the PCB from use, and in that case, you usually don't get AM, just FM works -- it's usually fixed by resoldering the switch connections on the PCB). I haven't heard of this happening on a 390 or 392, but I suppose it's possible.

I think the chances of it being a physical issue are a lot higher than it being an electronic issue -- but then, that's just a layman's guess. I am no tech.

Maybe hit the solder connection where the BFO switch is located with a solder gun, or add a bit more solder.

PS -- you're right about corrosion on battery terminals. It doesn't take much to cause power issues. I had this happen on a Superadio once. It was a slight bit of corrosion, but it was just enough to cause the radio to cut off at times.
 
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