Need some repair access

[f2shooter]

Afternoon everyone,

I'm finally getting back to listening and back to this web site but I've run into a small problem. The radio that got me into this hobby and with which I learned a tremendous amount is a Radio Shack DX390 that I found in a pawn shop for $10. The power supply I needed to operate cost more than twice that but oh well.....The other night I got up about midnight and tried to turn this radio on and got nothing. I've been using it regularly for quite some time without issue but now it isn't operating. I know it is getting power but thats about it. The light comes on and shuts off but when I press the power button nothing happens. My guess is the button has failed. Were would I find a source for a replacewment part or better still, who might work on these things and be able to repair it? Electronics isn't my strong suit and while it wouldn't be economical, I've learned so much with this radio I'd like to keep using it simply for fun. I've heard pirates, Chinese and Cuban propoganda, angry preachers we all apparently owe money to and much more using this radio and an antenna made from speaker wire. Who does this kind of work and how might I get in touch with them? No one locally offers this service so any help would be appreciated. Thanks.

 

[TGuelker]

Another option is to buy another DX390.

eBay has several

Here is one new in the box.

Vintage Radio Shack DX-390 HF/SSB/SW/MW/LW Receiver - NEW | eBay

Find many great new & used options and get the best deals for Vintage Radio Shack DX-390 HF/SSB/SW/MW/LW Receiver - NEW at the best online prices at eBay! Free shipping for many products!

www.ebay.com

 

[mmckenna]

I've got an old DX-440 that will give me headaches when the 2 AA batteries for the memory/clock start to go, even when running off the wall wart. Have you tried replacing those?

 

[Boombox]

Unplug the power supply. Make sure all batteries are out of the radio (if any). Press the power button once (will drain whatever capacitor is holding power in the circuitry somewhere). Let it sit for half an hour or so. Put some batteries in the radio. Try it. See if the reset works.

These older radios can develop glitches if not used periodically.

It's worth a try.

Also, try batteries. Check the battery compartment for corrosion. Exercise the power jack by inserting the plug, pulling it out, etc. The jack has a tiny switch and it may have developed oxidation from non-use. Exercising it my remove whatever oxidation could have developed on the little points in the switch.

I'd try these things before tearing into the radio.

Also, using batteries with these older SW radios is a lot better than using an AC power wall-wart. Some wall warts put out a lot more voltage than the radio is designed for. Won't kill the radio, necessarily, but isn't necessarily great for it either. DX-390s are pretty easy on batteries.

Hope you can get the radio to work again. I still use my DX-390. Very handy radio for SWLing, listening to the ham bands, and MW DXing (with a loop).

As for repair, I'd search locally for TV / Electronics repair. There are a few shops here and there that are still in existence. The DX-390 is a fairly straightforward radio, and the service manual is available online. I'm sure a repair tech who can fix modern stuff could repair a DX-390, especially if it's power-supply related. It sounds like your radio's issue is power supply related, as the circuitry seemed to be working fine for you when it was working.

 

[f2shooter]

I had never used batteries in this radio before. I let it sit for a few days and then loaded it up with fresh AA and D batteries and it started working immediately. Then I plugged the power supply back in and it works with that as well. Go figure. I think maybe it's just an old radio and gets cranky now and then.

Rick H.

 

[Boombox]

So glad to hear your DX-390 is working again!

Yes, they do get a little cranky, especially if they have been stored, unused, for any period of time. My DX-440 acted up a few times when I fired it up after several years non-use. My 390 also acted a little bit wonky as well. But they both work well now. Radios like to be used.

- - - - - -

The only thing I'd suggest now is if you use an external antenna with your DX-390, use a protection circuit, which can be as easy to make as a large resistor alligator clipped to the wire, with the other end to ground (it would bleed off static charges). Back to back (reversed polarity from each other) diodes can do the same thing. You'll want to protect your 390 from static electricity.

There is also a fairly easy to make circuit here on RR somewhere (KA3JJZ probably knows how to pin it here) that will protect your radio from static charges that can develop on external wires, during periods of T-storm / thunderhead activity, and during winter if there is very dry wind.

Oh, and I'll add here: where I live in the PNW, my DX-390 seems to pull in more SW stations with my indoor, 20-25 ft wire. But when I took it with me to northern Louisiana in the 1990's, any extra antenna overloaded the radio. So if you're hearing a lot off the whip antenna, you're doing OK. DX-390s have decent gain on SW, and in some areas the whip itself can get the job done. I remember hearing all sorts of hams on the 20 meter ham band -- just off the whip in Louisiana -- that here in my location (in a valley, in WA state) I would probably have needed an external antenna of some sort, even just 10-20 ft. YMMV. DX-390s are also pretty good on FM, and probably capable of FM DX, if you're into that.

It sounds like you're hearing a lot with your set-up now.