Trying to fix a solid-state boat-anchor SW receiver

[wkilleffer]

Greetings everyone,

I recently came into the ownership of an RCA Strato-World Mark One. It's a solid-state, made in Japan unit from the early 70s. The trouble is, I can't find squat on this receiver and how to fix it. I'm not sure what its model number is, nor where to find it on or in the case. I got it cheap because previous owner said it wouldn't receive anything. That's not correct, strictly speaking. Initially, it would receive on the FM, but for whatever reason, the volume was so low you couldn't hear it unless your ear was right up to the speaker. Well, a little careful cleaning and tweaking and that changed. Problem is, not so much for the better.

Now, sound comes through loud and clear, and won't respond to the volume control to turn down. It'll turn up louder, but won't go below a pretty robust mid-level volume.

This is one of those times that a schematic would be handy, because then I would be able to tell exactly what the wires running into the volume control pot were for, and whether that green thing by the pot is a capacitor or not.

But here's the worst thing: I have no idea how to remove the chassis from the case. There are pics out there of the chassis out of the case, and the person who did it will talk about how hard it was to remove, but no tips on where to start the process. I know it's hard... As much as I've taken apart over the years, I thought this would be a challenge but not so much that I would stymied from the start. May be another reason I was able to get it in the very low double-digits...

But anyway... Has anyone else ever dealt with one of these? I want to fix it, but not at the risk of making it worse in the process. I can post pics if needed. It's a pretty good-looking unit, very much a product of its time period. But so little information available... I know they weren't as popular as the Zenith Trans-Oceanics, but they weren't a rarity either.

Any assistance would be very much appreciated.

Thank you,
-William

 

[NutmegCT]

I see you've been getting suggestions on the Antique Radio Forum, so you may have already found this manual.

https://bama.edebris.com/download/rca/stratoworld/RCA Strato-World 3-BX-671.pdf

You don't have a photo or model number, so this is just a guess on the Strato-World.

Hope this helps!
Tom M.

 

[wkilleffer]

Hey Tom,

Thanks for trying, but that's the manual for the non-SS model. Probably the last tube-type Strato to come out before the SS models were released.

The guys at Antique Radio seem to believe that this radio was built buy a Japanese OEM so RCA could out their label on it, but even then, you would think a schematic would be out there somewhere. I may just have to take a few deep breaths and go for it. The scary thing is that I can tell by looking that this isn't just a matter of unscrewing three or four screws and lifting the chassis out. If that were the case, I would already be done.

 

[wkilleffer]

Ok, got the chassis out of the case. Had to clip the wires for the speaker and the signal meter. The pushbutton band switches on the front appear to have become dirty and dusty inside. Some people say that they're prone to breaking their solder joints. I didn't *see* anything that looked like that, but to see everything would require further sub-disassembly, and I'm not sure I want to go there. Too many wires criss-crossing here and there. This was plainly built during a different time. Lack of control for the volume is still an issue.

 

[JPSmit]

Ok, got the chassis out of the case. Had to clip the wires for the speaker and the signal meter. The pushbutton band switches on the front appear to have become dirty and dusty inside. Some people say that they're prone to breaking their solder joints. I didn't *see* anything that looked like that, but to see everything would require further sub-disassembly, and I'm not sure I want to go there. Too many wires criss-crossing here and there. This was plainly built during a different time. Lack of control for the volume is still an issue.

Not sure you have anything to loose by "going there" it doesn't work now, so, either you confirm it as a boat anchor - or you fix it - and if you dig down and it still doesn't work hopefully you will at least learn something.

 

[wkilleffer]

Went ahead and heated up and supplemented some of the solder joints for the switches, got it back into the case, and swapped out the volume control pot for a NOS replacement. The radio's reception is quite good and it's a neat unit.

Trouble is, even with the new pot, the volume control issue isn't solved. It's quieter at minimum volume than it was with the old one, but it still won't turn all the way down. It's like a resistor has gotten out of spec, but without a schematic, this is punching in at a higher pay grade.

 

[SaxMan]

Sounds like the signal going to the pot may be so hot that it's getting past the volume pot. I've had this happen with left/right issues on musical instruments where there is "bleed over" from a channel that is supposedly at zero volume. I'd try a high spec pot or a volume slider that is used on audio mixing boards. Or, if you want to MacGuyver it, put an on/off switch into the signal chain before it gets to the volume pot to act as a mute switch.

 

[Boink]

Many larger capacitors (especially electrolytic ones) can crap out over time. Old stereos often fail due to burned out caps.

 

[wkilleffer]

Many larger capacitors (especially electrolytic ones) can crap out over time. Old stereos often fail due to burned out caps.

Yes, but that tends to manifest itself in a hum, or what some folks refer to as motor boating. I was afraid that caps would be an issue for this due to its age, but it's hum-free on a/c or batteries.