Author Topic: Magnavox Stereo Theater 1MR418M restoration  (Read 5003 times)

Bill

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Re: Magnavox Stereo Theater 1MR418M restoration
« Reply #30 on: June 26, 2018, 06:41:47 AM »
No apology necessary Greg, it's a learning experience for all!

I think Ed is correct in that the round sensor under the picture tube is the light sensor.  Not sure where the remote mic/sensor is located. It maybe built into the remote electronics which is sitting next to the MPX thing, which is under the radio/tuner. There is a lot of stuff in this cabinet. ;D  Next time I go to the barn I'll check to see if the channel selector under the hood has numbers as well. 

Bill

electra225

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Re: Magnavox Stereo Theater 1MR418M restoration
« Reply #31 on: June 26, 2018, 10:13:59 AM »
Thank you so much, Paul.  Interesting.  That is the most complete explanation of the remote control system I have seen.  It even tells how to diagnose the system if the remote transmitter is missing.  That is the most intelligent conversation I have ever seen on AudioKarma.  :)

Perhaps I should develop a better attitude towards AK.   ;)

Bill, I  think I see a little red light above the TV tuner knob in one of those pictures.  What is the little red light for?  Remote on? TV on? None of the above?  According to what Paul posted and the information gleaned therefrom, we are looking for a little microphone doodad, location still unknown. 

Magnavox would hide things in the grille cloth.  There should be a pilot light in the grille cloth (maybe) on the end of the cabinet with the "Magnavox" script on it.  Or it could be in the panel at the bottom of the cabinet with the strip of metal running thru it.  The channel indicator in the corner of the CRT mask is just plain cool.  Very 1960's.   :)

Gloriously complicated!   :)
I'm great at multi-tasking.  I can listen, ignore, and forget all at the same time.

Bill

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Re: Magnavox Stereo Theater 1MR418M restoration
« Reply #32 on: June 26, 2018, 02:15:10 PM »
I'll take a peek at things and report back on my finds.  :)

Bill

electra225

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Re: Magnavox Stereo Theater 1MR418M restoration
« Reply #33 on: June 26, 2018, 03:06:47 PM »
I like this arrangement.  I have all the fun, you do all the work!   ;)

Have I found the "microphone doodad" that controls the remote?  ("Microphone doodad" will come back to haunt me before this project is completed!  ;))

Notice the device, buried in grille cloth (?!) with the red wire coming off it.  Under the tuner.  Could this be it?

Edit:  I looked again at the pictures on AK that Paul posted.  I'm more sure now than I was, although not positive.  The one on AK has the same single red wire coming out as this one does.

You are going to get attached to the old ST, Bill.  You're gonna miss it when it's gone.  You'll have to come down here to help me fix it so you can see if I'm doing it right!   ;)
I'm great at multi-tasking.  I can listen, ignore, and forget all at the same time.

walyfd

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Re: Magnavox Stereo Theater 1MR418M restoration
« Reply #34 on: June 26, 2018, 04:42:40 PM »
Any idea what it all weighs?  The furniture quality was so superior then.  Fill it with tube goodies and brace the floor.  I think I heard my house groan when the Fisher took residence...

electra225

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Re: Magnavox Stereo Theater 1MR418M restoration
« Reply #35 on: June 26, 2018, 04:54:24 PM »
Bill can tell you more about its weight than I can.  I'm guesstimating it somewhere close to a Concert Grand, maybe 150 pounds.  The cabinet is 2" longer than the CG.

I have a bench made especially for the big Magnavoxes.  4' X 8', 2 X 6 construction, cross beams set 12" on center.  4X4 legs, braced by 1X4's, 32 inches tall.  It takes four of us old guys to get the big ones on that bench. 
I'm great at multi-tasking.  I can listen, ignore, and forget all at the same time.

ed from Baltimore

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Re: Magnavox Stereo Theater 1MR418M restoration
« Reply #36 on: June 26, 2018, 05:05:50 PM »
          I think the red wire is the ultrasonic sound sensor. There wouldn't be 2 wires because its probably a high impedance piezoelectric pickup and would have a shielded wire going directly into the metal case so to be totally shielded. The other end probably goes to some kind of shielded phono plug and goes Into the remote chassis.

ed from Baltimore

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Re: Magnavox Stereo Theater 1MR418M restoration
« Reply #37 on: June 26, 2018, 05:15:03 PM »
  the ad also said the unit had "videomatic."  would that be a similar round light sensor that adjusted the brightness with room lighting?   

Bill

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Re: Magnavox Stereo Theater 1MR418M restoration
« Reply #38 on: June 26, 2018, 09:16:31 PM »
I'm guessing Greg's ST is 200 plus pounds.  It's full of electronics from one end to the other with no room to spare.

Bill

electra225

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Re: Magnavox Stereo Theater 1MR418M restoration
« Reply #39 on: June 26, 2018, 10:55:45 PM »
I "thought" I saw an ad that called the room brightness system "Magnalux".  That ad does indeed call it "videomatic."  I believe it is safe to assume that the round red thing in the middle of the picture tube is the sensor for that system, whatever we want to call it.  I see the wires for the traditional Magnavox pilot light, but have not found the light yet.  The wires appear to disappear under the TV chassis, for what that is worth.

You said the casters worked fine, Bill, so that will certainly help.  The big instruments are lots easier to handle with casters.  At 200+ pounds I can lift my end, but I don't want to hold it for very long!   ;)

We'll load it in my little trailer that is lower to the ground than the Tahoe.   ;)
I'm great at multi-tasking.  I can listen, ignore, and forget all at the same time.

electra225

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Re: Magnavox Stereo Theater 1MR418M restoration
« Reply #40 on: June 26, 2018, 11:23:27 PM »
Three tidbits of nomenclature for today's adventure into "The Rest of the Story"...

*Chromatic Optical Filter
*Video-matic tuning
*Magnalux

(Magnavox LOVES the words "automatic" and "automatically".  Bear with me....)  ;)

The jury is still out on Chromatic Optical Filter.  Just trust me, it's in there.....

Videomatic or Video-matic tuning:

"Video-matic fully automatic TV"
"Videomatic automatically assures you of the best picture, always, regardless of room light".

Magnalux:

"Magnalux Automatic TV Light Meter"

"Like a self-setting camera, this automatic TV light meter measures the room light and automatically adjusts the brightness and contrast- now you can enjoy the best picture always, night or day".

So, is the little red round sensor in the middle of the cabinet under the picture tube for the Magnalux system then? 

I read three times before what I shared just now made any sense.  Videomatic is included in the circuitry of the TV, just where we shall find out one of these days.  Sure is a lot of "automatic" stuff on one of these TV's.
I'm great at multi-tasking.  I can listen, ignore, and forget all at the same time.

ed from Baltimore

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Re: Magnavox Stereo Theater 1MR418M restoration
« Reply #41 on: June 27, 2018, 02:52:05 AM »
      videomatic might be automatic fine tuning  which was actual AFC and almost a necessity on a color set. the black and whites might get away with preset fine tuning which had 12 little gears and eccentrics around the dial and remembered your fine tuning adjustment for each channel individually.

       If you shine a flashlight on the light sensor and the picture  gets brighter then that's definitely the automatic brightness control.  but the remote ultrasonic sound pickup is also a small round thing on the front of the set somewhere. I guess you have to trace the shielded red wire from the back side remote chassis. It might be under the speaker grill cloth since it doesn't need to let light through like the room light sensor.


          chromatic optical filter might be a sheet of grey tinted glass bonded to the picture tube glass. supposedly it improves contrast in a brightly lit room by making reflected light make a two way trip through the tinted glass and therefore be attenuated twice while the picture off the screen only makes a one way trip through the tinted glass.

electra225

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Re: Magnavox Stereo Theater 1MR418M restoration
« Reply #42 on: June 27, 2018, 08:36:09 AM »
You may have nailed Videomatic, Ed.  There is no fine tuning knob on the channel knob.  All the normal controls are placed on the back of the cabinet.  I can't imagine an old black and white all-tube TV that would not run vertically and/or horizontally when you start it up.  Or not need some other adjustment before you could watch it. 

Vidoematic and Magnalux seem to me to be fairly advance features for the time.  The old TV guys have little good to say about Magnavox TV sets in general.  Any idea why that might be?  Is there something inherently wrong with Magnavox TV or are they just not an RCA or Zenith?
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ed from Baltimore

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Re: Magnavox Stereo Theater 1MR418M restoration
« Reply #43 on: June 27, 2018, 12:47:07 PM »
   I don't know why I've only seen 2 Magnavox TVs in the flesh ever, one an early 50's chassis only with no audio circuits that probably slid into a radiophono as an option. It seemed rather well designed and constructed to me. The chassis metal was shiny and smooth, the 5U4 plugged into the top of the large power transformer, it had a 17" rectangular picture tube fastened to the chassis 3 or 4 IF stages, plenty of good circuits, and actually worked well and had a good picture. The other was a roundie mid sixties 21" color console that I was always adjusting for my friends parents and was on all day long and had a dimming picture tube. It had a lot of automatic adjustment features with extra pushbuttons to optionally enable or disable them, if I remember right which probably didn't help their reliability, and I seem to remember noisy tuner and switch contacts, but that house was a dusty one and had a cat and a dog too.
          The stores that carried Magnavox in the Baltimore area were stores that had furniture, clothes etc and appliances wasn't their main thing and their service departments maybe just never saw many Magnavox TVs to get really used to them like more commonly sold RCA, Zenith, Philco, Admiral and other medium priced brands. I worked in the parts department at Luskin's discount appliance store for 9 months, so I never saw a Magnavox chassis being worked on service call guys made small adjustments in the home and dragged in the chassis for the real repair problems. They were used to the most common models and didn't like working on the seldom soldones. They probably wouldn't have liked Magnavox just because they never would have seen many, I=f we carried them

Motorola Minion

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Re: Magnavox Stereo Theater 1MR418M restoration
« Reply #44 on: June 27, 2018, 01:26:26 PM »
Magnavox B-W TV's of the late 50's thru 1960's were good, not great though.

The build quality was good, but TV design was fair at best. I had one from 1956, 1958 in my former collection.

Nothing on the TV chassis was hard to fix, and they kept playing when you nailed it, but the picture was never Zenith quality.
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Dave