Author Topic: Another orphan followed me home  (Read 33804 times)

TC Chris

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Re: Another orphan followed me home
« Reply #90 on: July 31, 2019, 11:56:18 PM »
Dammit, I drew up a tube placement chart for it and have no idea where I put it.  I know they added up to about 120V.  25 volt output tubes x 2, 12 volt tubes x6, and a 35 volt rectifier?  Then there's the separate MPX unit, 6V x 2.

The transformer had a bunch of wires, more than just the 4 you'd need for isolation.  Wouldn't it be nice to have a schematic? 

Chris Campbell

electra225

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Re: Another orphan followed me home
« Reply #91 on: August 01, 2019, 08:41:19 AM »
A schematic would be nice, but it does not appear like you are going to get one.  In the way of a suggestion, after you get the chassis out and turned over on the bench, find out what that transformer does.  Let's say, just for the sake of argument, that it powers up the heater string with a 1:1 tap, and also the 6-volt heaters for the MPX adapter.  That, along with the wires for the primary, would give you at least six wires.  I'd think that rather than worrying about a schematic, your questions might better be answered by simple observation and by making some voltage measurements.  I know.  Backseat drivers are always the experts...... ::) :-[ :-\ ;) :)
I don't need Google.  My wife says she knows everything.

TC Chris

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Re: Another orphan followed me home
« Reply #92 on: August 01, 2019, 10:21:28 PM »
Wow, what an optimist... "after you get the chassis out and turned over on the bench"...  it doesn't come "out" because it's all hard-wired IN.  It is not, shall we say, designed for easy service. I still dream of a nice schematic that I can study  and figure out values and voltages from.

Tonight's project followed my purchase of Velcro at Ace Hardware on the way home from work.  There were umpteen choices and I ended up buying "industrial strength."  I was hoping that referred to the self-stick adhesive (they were all self-stick).  Then it dawned on me that nothing would stick very well to the back of the Masonite because it has that grid texture on it.  So I mixed up some 5-minute epoxy and applied it in patches to the place where I'll stick the Velcro.  That should provide a smooth, stickable surface.  If the other half of the Velcro doesn't adhere to the primary (console-side) baffle board, I can staple that.

Chris Campbell

electra225

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Re: Another orphan followed me home
« Reply #93 on: August 01, 2019, 11:58:46 PM »
I apologize for assuming facts not in evidence.  You have this under control, so you don't need my two cents.  Good luck.
I don't need Google.  My wife says she knows everything.

TC Chris

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Re: Another orphan followed me home
« Reply #94 on: August 04, 2019, 06:25:02 PM »
Today I installed the new speaker grilles.  I'm not entirely happy.  The left one squeezes a bit into its recess, which make a loose spot in the grille cloth.  I'm pondering ways to either stretch the cloth a bit, possibly remove one glued edge and re-glue it, or maybe even rout a slightly larger recess.  Here's a photo.  Actually, the effect is quite good.  I just want it to be better.

The good news was that I had the foresight NOT to latch the changer down, so I could pull it out from the top.  I'll take it home for clean & lube.  The motor rotor feels very stiff.

Chris Campbell

electra225

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Re: Another orphan followed me home
« Reply #95 on: August 04, 2019, 11:09:43 PM »
That grille cloth, when it was installed at the Magnavox factory was both glued and stapled.  Glue, by itself, without support, is not stout enough to withstand the mechanical stress placed on the cloth when you install the boards into the cabinet.  All the glue really does is to keep the cloth from moving as the speaker cone moves air.  The speaker boards are really tight in all the Magnavox cabinets I've worked on.  I'm guessing the boards are in there so tight so they don't "drum" when the big speakers move.  In the way of a suggestion, I would not stretch the cloth, just make sure it's flat and tight.  Then run a row of 1/4" staples (from the back) down the sides and across the top.  Say 6 on the top and bottom and 10 or so on the sides.  Make sure you eliminate wrinkles as you staple.  Start at one end and work toward the other.  Don't work each end toward the middle lest you bunch up the material.  Make sure to trim the corners so they are not too tight, since the cloth will bunch up there where it folds.  The advantage to staples is that if you don't get it right, you can pull the staples and do it over without damaging the grille cloth.  That old straw cloth is not going to be happy if you stretch it any at all.  You have the cloth so nice and straight on the boards, which is the hard part.  And it is going to look really cool when you get it sorted like you want.  It just needs a little more support on the edges then you'll be stylin'.   :) :)  That's my two cents and has been my experience.  Good luck.   :) :)
I don't need Google.  My wife says she knows everything.

Bill

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Re: Another orphan followed me home
« Reply #96 on: August 05, 2019, 08:43:57 AM »
I do not see any problems in the photo.  It looks good Chris.

Bill


electra225

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Re: Another orphan followed me home
« Reply #97 on: August 08, 2019, 11:18:39 PM »
Any progress on the grille cloth situation, Chris?
I don't need Google.  My wife says she knows everything.

TC Chris

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Re: Another orphan followed me home
« Reply #98 on: August 09, 2019, 12:12:12 AM »
Not 'til the weekend.

Chris Campbell

TC Chris

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Re: Another orphan followed me home
« Reply #99 on: August 13, 2019, 07:38:18 PM »
 brought the changer from the little console home with me ten days ago.  Last night I took the motor apart.  The bottom bearing was seized up.  So much so, in fact, that when I popped the bottom bearing assembly off, the little sintered bronze bearing itself pulled out of the lube reservoir/housing.  I couldn't poke it back through the spring-bronze fingers that secure it, so I pried the assembly apart.  That let me lube it up again after soaking in solvent.  Then  crimped it back together and assembled the motor.  The rotor would spin.

Tonight I took the Molex AC power connector apart, pulling out the little contact fingers so I could poke them into an extension cord.  The rotor rotated reluctantly.  I took pliers and twisted the bearing housing until it spun freely--had to get the upper & lower bearings aligned.  Then it took off running happily.  I cleaned the idler wheel but the rubber feels really hard.  I stuck it in the drill press and sanded some of the outer surface off but it still felt hard.  Maybe it will work--by this time the Molex was reassembled so I won't be able to tell if it has any function left.  I also cleaned out the old grease in the turntable bearing, not because it was very hard, but just because.  So now I think I've got a functioning turntable, or at least one that's close and will be cured by a new idler.  We'll see.

Chris Campbell

TC Chris

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Re: Another orphan followed me home
« Reply #100 on: August 18, 2019, 02:19:06 PM »
I took my refurb'd VM changer in today to replace it in the console.  Plugged in audio cables and power Molex connector and... nothing moved.  When  first got this one pin fell out of 1/2 of the Molex unit and I poked t back in where it looked like it should go.  Think  I guessed wrong.  Got out a voltmeter and two of the three leads are 120 VAC with respect to the 3rd.  (???)  They're -0- with respect to each other.  So that means the colors on one side of the connector have nothing to do with those on the other side.  I traced the changer wiring and figured out which is which.  Checked the switch and it's working; checked motor field continuity and it's OK too (besides, I had the motor running on my bench).   Of course, the leads are all too short to allow inspecting the situation with everything plugged in.  I was gong back & forth and on the last try, the little flip devices that secure the changer in place flipped in the lock position and I couldn't remove the changer again without taking off the back of the console.  @#&*^%!!!!, or something to that effect.  I am pining for the old Amphenol plug we discussed a while back.  I may try to wire it up better next time but I had run out of time for this effort.

I also delivered the Chevy's new gas tank & fuel line to the Chevy's trunk, but couldn't start it up & drive because there's a dumpster in the way after the garage was re-roofed yesterday.

Chris Campbell