Vintage HiFi Audio Forum
General Banter => Welcome Wagon => Topic started by: Mongojustpawn on September 14, 2014, 09:56:07 PM
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Hi everybody, I'm new here, just found the site yesterday, lurked around some, decided to join up. I'm kind of local, near Kittanning, just getting into some audio gear after my retirement last year. have a small Pioneer sx440, that needs some help and a Grundig majestic console I rescued from the dumpster during summer clean out, not working. Been prowling online for info on both, also reading some text books on electronics, also doing some soldering on some junk boards.
Gary
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Welcome.
Is your Grundig a tube unit? >:D
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I'd be shocked if it's not.
The great thing about those old tube consoles is that they are fairly easy to work on. I know almost nothing, have never read a book on electronics and have rehabbed a couple of them. The tube tester at the shop is free, a DMM is all that is needed to test the transformers and resistors, and most caps should be replaced anyway. Pretty straight forward stuff.
What kind of help does your 440 need? I'm currently doing some light rehab to a 450.
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Welcome, and enjoy the ride.
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Welcome!
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Welcome to the forum!
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Greetings Mongo!
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NEW BLOOD!
Watch out man, these guys are rough.
They will break your balls, bash your bose and tell you how much your stuff sucks.
Just kiddin'
Nicest guys on the planet.
Welcome aboard.
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They will break your balls, bash your bose and tell you how much your stuff sucks.
BOSE is awesome!
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They will break your balls, bash your bose and tell you how much your stuff sucks.
BOSE is awesome!
See what I mean?
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Hi Guys, Thanks for the welcomes. The Grundig is a tube set, model ms-40 or 41, am,fm,sw tuner with TT, looks complete and unmolested. I did plug it in to try it when I first got it home, didn't know better, tuner lights up, and the tubes all appear to glow, but no sounds. Other than looking for loose or broken connections, haven't done anything else. The sx440, suffers from left channel distortion and weak fm reception, stereo indicator light not working. I'm thinking of recapping the PS, and see where that leads. Any thoughts?
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First thing to do is DeOxit all pots and switches. A flaky tape monitor switch will give the symptoms you report. Then once everything is clean, measure the DC offset.
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That's regarding the Pioneer, not the Grundig. First thing to do on the Grundig is measure all the iron.
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Careful plugging that tube stuff in, and more careful probing around in there. Check out antiqueradio.org, among other sites for useful info.
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Where around the 'Burgh are you located, Mongo?
When you are working with the Grundig, a good rule of thumb is to keep one hand in your pocket while probing for current / voltages and the like.
If you powered up the unit and the tubes glow, your power transformer is most likely just fine. The next thing I'd do would be remove all the tubes and test them. A few members have testers as does the shop.
It's a good idea to check resistors with the tubes removed. Any resistors that are out of spec should be replaced.
It's also a good idea to replace any capacitors that are in the signal path.
You may want to replace power supply capacitors as well. Sometimes they stand the test of time, sometimes they don't. Some say this is a mandatory replacement while others say if it's not broke, don't fix it. This step can be a preventative measure to prevent failure down the road as well. You won't know the current status of your power supply capacitors until you power the unit up on a Variac. If you don't have access to one, google "Poor Man's Variac" and have at it.
Best of luck!
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First on the pioneer, did the deoxit a couple times, also cleaned and lubed the tuner as described on audio karma, cleaned tape monitor switch and worked it, as well as all the other switches, just checked offset, also per AK, rt ch 130mv, lf ch 200mv. As for the Grundig, I'm leery of doing anything until I'm more sure of myself, I've read about the high voltages, on some other sites. What are thoughts as to recap of PS? Also, I'm located near Kittanning, about 40 miles up the Allegheny.
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BOSE=Big Ordinary Sound Everywhere. Kittanning is one of the nicest pools of water on the Allegheny. Welcome-this is a great place to have fun
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I'm about 1/10 mile from the river, river view vs. river front.
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Is Sirena Pizza still open? ;D
BOSE: Bastard Owner Sues Everyone
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River views are good and if you are in town, 1/10 mile from the boat ramp. Excellent
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Sirena pizza still open, used to go there a lot, but the food and service got really sketchy, haven't tried them for a couple years, maybe they've gotten better.
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My dad and I used to stop in at Sirena's after fishing the Allegheny. I haven't been there since the late 1990s.
Don't doubt your budding abilities. Everyone ruins more good gear than they repair when first starting this hobby. :)
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Those offset numbers are far out of line. Likely culprit is bad output transistors, but it could be other issues as well.
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8Wof F, where did you fish? Sir Thrift. Lot, the output transistors, they're the flat silver ones? I measured the voltage between the 2 pins, all about .4-.5 MV. They're 2sd266. Maybe the moderator should move this discussion to a more appropriate section.
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Typically upstream from the bridge and locks. The was a road (SR 423, perhaps?) that ran parallel to the river on the opposite side from town that had decent access. Also, driving out of town along the river along Johnston was doable as well. I understand there's a trail there now days. Sometimes we'd even go on Pine Creek but never really had decent results up there.
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Welcome Gary!
Glad you joined the Forum. Good people with good advice.
Good luck!
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Sir Thrift. Lot, the output transistors, they're the flat silver ones? I measured the voltage between the 2 pins, all about .4-.5 MV. They're 2sd266.
I'm a hack, but this guy knows his stuff...
http://www.audiokarma.org/forums/showthread.php?t=43186&highlight=testing+transistors (http://www.audiokarma.org/forums/showthread.php?t=43186&highlight=testing+transistors)
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I never bothered testing them. At $.63 each, if I have any doubt I just replace them.
http://www.digikey.com/product-detail/en/2SD2662T100/2SD2662T100CT-ND/1782339 (http://www.digikey.com/product-detail/en/2SD2662T100/2SD2662T100CT-ND/1782339)
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Good read STaL
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Welcome to the...
(http://www.novablack.com/wp-content/uploads/2014/07/bAs2ifQ.png)
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Just noticed the Mongo avatar, and the line from the movie. To quote Montgomery Burns,
"Excellent".