I had a pretty good haul the other day, which included a neat Realistic STA-53 stereo receiver. Only obvious problem is that the light for the tuning is out, and the controls are a wee bit noisy.

The top of the box is wood. While I was listening to a local AM station, I noticed that when I touched the wood, the reception was better, but my fingers felt somewhat tingly... I've never experienced the tingling before, does it suggest any dangerous problems? Anyone encountered it before?

Can anybody shed some light on the STA-53 model line in general, for that matter?

(pictures and further description at post 5 (http://audiokarma.org/forums/showpost.php?p=1274029&postcount=5) )

If that is really an electrical tingle you are feeling, it is NOT a good sign. I seriously doubt that Realistic is early enough to be be one of the devices that would have a "live" chassis, and even then it shouldn't reach the case, so you definitely have an electrical problem there.

Even scarier is the idea that you are feeling this when touching WOOD! Wood is an insulator, although it may carry a static charge: are you sure this isn't woodgrained metal? Anything putting out enough charge to be felt through the wood case is a potentially dangerous situation.

I suggest checking that gear out VERY carefully -first a good visual inspection with it powered OFF for at least a half-hour (to let capacitors fully discharge) looking for frayed insulation, wrong or broken connections, etc... then, if you don't find anything, with power on (one hand behind your back, wearing gloves and using a meter) to find out what where the problem is. In fact, unless you understand electricity and electronics reasonably well, let a knowledgeable tech do this for you.

As for getting better reception when touching the thing, that is a common and normal occurence. Essentially, you are adding your body to the antenna system. Some of those light-touch switches that you don't even quite have to touch to operate act on the same principle, as do those AM induction-loop antenna boosters which only have to sit near enough to the AM antenna (without even touching it) to improve reception. I have even tested receivers before, when I didn't have antenna wire, by touching the antenna connection with a finger; sometimes it can help reception enough to bring in stations that otherwise can't be detected! Ever have/remember the old TVs with the rabbit ear antennae? You would get them all adjusted right, then go sit down and the reception would be off -- because your presence next to them/touching them while adjusting them was affecting the system, altering reception! Same principle.

However, given that you are feeling current discharge when touching it, there may be something else going on here, as well, that you definitely want checked and corrected!

I had a pretty good haul the other day, which included a neat Realistic STA-53 stereo receiver. Only obvious problem is that the light for the tuning is out, and the controls are a wee bit noisy.

The top of the box is wood. While I was listening to a local AM station, I noticed that when I touched the wood, the reception was better, but my fingers felt somewhat tingly... I've never experienced the tingling before, does it suggest any dangerous problems? Anyone encountered it before?

Can anybody shed some light on the STA-53 model line in general, for that matter?

I dont know what an STA-53 is, but I'll take some meaningless stabs ----If it is a Vintage receiver from the 70's, almost all Realistic units had "genuine Walnut veneer" case, and clearly stated so on a sticker that may have easily been removed. If the case is metal however (with a woodgrain finish) some things may make sense that have been touched on long ago on this site.
I'm referring to the "tingling" sensation here, and without going into the nitty gritty, simply unplug the unit and flip the line cord polarity the other way --- if the tingling is what I think it is----it will disappear. As well, some AM radios did actually use the line cord as the AM loop antenna, and by touching the metal case (if the above condition exists) you are becoming an extension of the antenna, enhancing reception in some cases, and inhibiting it in others. Changing the signal strength of a tuned in station may change simply by walking around in the room, or changing the shelf or location that the tuner (receiver) sits as well.
If not, well then it wont, and I have no idea what is going on (a Sanyofreak Yogi-ism).......
Oh yeah, nothing dangerous goin on here, if there were, it'd be more than a tingle, as long as You werent a roaming garden gnome. "Tingly"!!!!

The case is definitely wood on the sides, top and bottom. It looks like a later SS unit, I'll get some pics up after I fool with it next.
I unplugged it after I noticed the issue because I was a little concerned about it self-destructing. I'm going to try reversing the plug and also testing if it does the same thing on FM. Also going to check out severity/actuality of the tingling.


PS. I remembered after posting that I had been using a speaker wire as AM antenna because it was handier than a proper antenna. + side of it to antenna, the other to ground, then laid it over towards my window. Could that cause problems?

So now I don't seem to be getting the tingling. It might have been the power of suggestion... my gf noticed it as she was about to pick up a tuner I had stacked on top, and then I was noticing it. Or perhaps the tuner was touching something. I think that it's fine though. Except it thumps a bit when I power it on. On the front it says Realistic STA 53 Solid State AM/FM Stereo Receiver. On the back, by model, it seems to list itself as a 31-8000. Another user on this board has a Realistic EQ with the same model number. Can't find any info other than that. Anyhoo, here are some pictures.

You can see missing light here.
http://i184.photobucket.com/albums/x294/Borteep/IMG_4290n.jpg

As you can see in the next two photos, that is most certainly not wood-grained metal
http://i184.photobucket.com/albums/x294/Borteep/IMG_4291n.jpg

http://i184.photobucket.com/albums/x294/Borteep/IMG_4292n.jpg


Only one speaker attached while I'm testing functionality. Is that a bad habit?

I recall reading a reference to a "safety checker" for assessing electrical equipment. Any such thing? I'd guess it could tell you if there was any substantial current behind any voltage on the unit's exterior.

And a question not a suggestion. Could you connect the ground lug for phono to an actual earth ground, like an outlet face plate, or cold water pipe? Wouldn't that have the same effect as a three prong plug?

Sony actually recommended it for their STR6046A receiver, and I tried it without deleterious effect (although the receiver already had some problems). But I don't know if it's a wise idea in general.

Of course, my fear is that doing so would, in a truly defective receiver, cause a huge current flow that at least would trip a circuit breaker, and some slight possibility of a fire.

Then there's the matter of death caps and floating grounds... :(

Me, I wear rubber soled shoes a lot.

And, the main problem I can see with hooking up only one speaker for testing is that you will more likely miss any anomolies in channel balance. In my bitter experience that's a major source of problems with audio amps.

Only one speaker attached while I'm testing functionality. Is that a bad habit?

How do you check for stereo operation with only one speaker hooked up? Even if you move the one speaker to the other side, and you hear music... you can't tell if you have stereo separation, or be able to compare output sound levels at the same time (weaker channel).

IMO you can't check out the functions fully on one speaker, just as you can't assume the phono inputs work without hooking up a turntable...

she's a beaut! About the same vintage as my SA1000-A/TM-1000 combo.

What rt426 said... To know, you've to try both speaker outputs, all inputs including phono if you can, and a check of the headphone jack would be of utmost importance to a cans addict such as myself. the realistic gear I have of this era have nice headphone amps.

Tingling suggests AC current, not DC. I think it might be a combo of service plug polarity and a leaky filter cap? Maybe there's enough salty dirt residue on the surface of the case to leak some AC across the finish? Especially if you were touching another good ground source? I'd clean the case with Orange Glo, or Murphy Soap and see if it goes way. All cleaning done unplugged. Maybe this was on someones boat or something? You never know?