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 Post subject: Emerson 609 projection TV restoration
PostPosted: Aug Wed 09, 2017 12:05 am 
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Location: Woodinville, WA USA
I've been working on an Emerson 609 projection TV recently, and the electronics seemed to be working pretty well after recapping and other basic chores. The 45-degree plane mirror also needed recoating, so I sent that off. After I reinstalled the mirrors, things started to go south. The focus wasn't great to start, and now it has gotten even worse, while the overall image size suddenly shrank by about half.

You can read more (much more) by looking at this article-in-progress; it includes links to the full Riders and Sams service manuals:

https://antiqueradio.org/Emerson609Proj ... vision.htm

Scroll down to the end if you're impatient and want to know where things stand right now.

Has anyone restored an Emerson 609 before? I'm fairly confident about the electronic side, but the Norelco Protelgram optical box with its mirrors & lens & whatnot is new to me.

I'd appreciate any advice from someone who has tamed one of these beasts. At this point, my plan is to move all the chassis back onto my workbench and start looking for a cause of the sudden reduction in image size. You can see on the CRT face that the image is smaller than normal, so I assume the problem is on the electronic side, not in the optical/mechanical parts.

Thanks!

Phil Nelson
Phil's Old Radios
http://antiqueradio.org/index.html


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 Post subject: Re: Emerson 609 projection TV restoration
PostPosted: Aug Wed 09, 2017 1:51 am 
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Location: parkersburg west virginia
The problem may be related to the power supply. the section of the supply that supplies voltage to the focus circuit, also supplies the plate voltage to the Horizontal & vertical oscillators, screen grid on the 6BG6, & both vertical & Horizontal centering controls are tied to it as well.
it mat be a defective capacitor in the voltage doubler circuit or the section of the ballast tube itself.


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 Post subject: Re: Emerson 609 projection TV restoration
PostPosted: Aug Wed 09, 2017 2:41 am 
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Location: Lafayette, CO
You can measure the voltage of the doubler (+ and -)....ballpark is close enough. The biggie is what you see on the face of the 3NP4. The rest is (non)smoke and mirrors. If that is crisp and within the range of the focus (electrical), you are golden. Perhaps the focus coil is not quite close enough to the crt bell? Craig


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 Post subject: Re: Emerson 609 projection TV restoration
PostPosted: Aug Wed 09, 2017 2:59 am 
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Thanks, that gives me some starting points. It does feel like a power supply failure of some sort.

Regards,

Phil Nelson


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 Post subject: Re: Emerson 609 projection TV restoration
PostPosted: Aug Wed 09, 2017 8:21 pm 
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It was a power-supply problem, yeah. A broken lead between C6 and the junction of M3/M4 (Sams schematic) caused that line to supply zero volts.

I temporarily reconnected the broken wire with a clip lead, which restored the power and full deflection. Now I'm back where I was before, with lousy focus. This is the best I can get using the two electronic focus controls:

Image

The focus on the CRT face looks good to my eye, so I'm guessing that one or both of the reinstalled mirrors is cockeyed. I didn't mess with any of the mechanical adjusters before, of which there are several. It's possible that some mechanical adjuster was seriously screwed up long ago, but the image that I got before resilvering the mirror was closer to normal focus (and correct screen geometry) than this. Maybe I'll spot something obvious after I open the optical box back up.

Phil Nelson
Phil's Old Radios
http://antiqueradio.org/index.html


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 Post subject: Re: Emerson 609 projection TV restoration
PostPosted: Aug Thu 10, 2017 1:37 am 
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Location: parkersburg west virginia
philsoldradios wrote:
It was a power-supply problem, yeah. A broken lead between C6 and the junction of M3/M4 (Sams schematic) caused that line to supply zero volts.


I'm glad you found the broken lead. that's the trouble with bad lead routing that Emerson used when building this chassis

philsoldradios wrote:
Image

The focus on the CRT face looks good to my eye, so I'm guessing that one or both of the reinstalled mirrors is cockeyed. I didn't mess with any of the mechanical adjusters before, of which there are several. It's possible that some mechanical adjuster was seriously screwed up long ago, but the image that I got before resilvering the mirror was closer to normal focus (and correct screen geometry) than this. Maybe I'll spot something obvious after I open the optical box back up.


By the looks of the screen, It appears that one of the mirrors is off center.
The "focus" problem appears to be caused by a smudge, or some contamination on one of the mirrors or on the face of the crt.


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 Post subject: Re: Emerson 609 projection TV restoration
PostPosted: Aug Thu 10, 2017 6:16 pm 
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Spherical mirror is off center. Craig


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 Post subject: Re: Emerson 609 projection TV restoration
PostPosted: Aug Fri 11, 2017 1:44 am 
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OK, I pulled the chassis and opened the optical box. The spherical mirror doesn't have adjusters as such, but the holes in the box are bigger than its mounting screws, providing a little wiggle room:

Image

Large washers go on both sides of the hole, so clearly some sliding back & forth was contemplated.

With all three screws loosened, you can slide the mirror a bit in any direction. Not foreseeing that alignment would be an issue, I have no record of exactly how it was mounted before I removed the mirrors. Nor do I know exactly where it was mounted when it produced the most recent picture, since I didn't know the screws had any leeway until I had loosened them all.

I don't have a factory jig for aligning all this stuff, so unless someone has a better idea, I'll mark the box with tape tags showing the center of each mounting hole, and try to remount the mirror dead center in all three holes.

Also on my to-do list is checking the angle of the plane mirror to make sure it's exactly 45 degrees, and to ensure that each of the three clamps is holding it the same distance from the struts (i.e., even if it's lying back exactly 45 degrees, it's not tilting sideways, either).

These adjustments have to be done blind, as it were. The 3NP4 CRT spews X-rays, so you can't just open the box and stick in your hands to fiddle this stuff while the TV is playing, watching the screen to see what happens.

Phil Nelson
Phil's Old Radios
http://antiqueradio.org/index.html


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 Post subject: Re: Emerson 609 projection TV restoration
PostPosted: Aug Fri 11, 2017 3:24 am 
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Location: Albion, CA, USA, 95410
Yikes. Having had to align telescope mirrors I can't imagine having to re-assemble/dis-assemble between each adjustment. How about using a laser pointer, alternate image producer of some sort or something? Maybe a slide projector somehow? Even just a flashlight? It just seems really hard to do otherwise, at least getting closer to the ballpark before going to the in/out.

Best of luck!


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 Post subject: Re: Emerson 609 projection TV restoration
PostPosted: Aug Fri 11, 2017 7:33 am 
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Perhaps I could print something like this test pattern on a translucent sheet and lay that on top of the corrector lens:

Image

Then I could tell whether the image leaving the top of the box is grossly misaligned. If the image is focused on the CRT face, it seems like it should be focused after it exits the corrector lens.

I would still need to open up the box for each adjustment, and close it for each trial, but at least I could place all the chassis on a workbench and work there instead of crouching on my knees behind the cabinet.

Phil Nelson
Phil's Old Radios
http://antiqueradio.org/index.html


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 Post subject: Re: Emerson 609 projection TV restoration
PostPosted: Aug Fri 11, 2017 3:13 pm 
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Location: Albion, CA, USA, 95410
Sounds like a plan. There has to be some way of doing it, I can't imagine that in the factory they didn't have some kind of "cheater" for alignment. Or, maybe everybody just got a lot of x-rays. :shock: Let us know what you end up doing and how it turns out.


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 Post subject: Re: Emerson 609 projection TV restoration
PostPosted: Aug Fri 11, 2017 6:07 pm 
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[quote="madlabs"..I can't imagine that in the factory they didn't have some kind of "cheater" for alignment...[/quote]

They did. Wonder what it would take to fabricate one ?
http://www.earlytelevision.org/philips_test.html


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 Post subject: Re: Emerson 609 projection TV restoration
PostPosted: Aug Fri 11, 2017 6:34 pm 
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Location: parkersburg west virginia
bandersen wrote:
[quote="madlabs"..I can't imagine that in the factory they didn't have some kind of "cheater" for alignment...


They did. Wonder what it would take to fabricate one ?
http://www.earlytelevision.org/philips_test.html[/quote]


I'm wondering if one of those Big Maglight flashlights could be used to make this tool with. it appears to be about the same size.


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 Post subject: Re: Emerson 609 projection TV restoration
PostPosted: Aug Fri 11, 2017 8:25 pm 
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Location: Lafayette, CO
Perhaps putting a millimeter scale on each of the four sides can help. Just log adjustments as you go....can be frustrating remembering where you were. The tube face has focus so you are almost there. I doubt anybody else has brought these Emerson projection sets back from decades of disuse. Craig


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 Post subject: Re: Emerson 609 projection TV restoration
PostPosted: Aug Sat 12, 2017 6:19 am 
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OK, I was wrong about using a pattern placed on top of the corrector lens for alignment. I made a pattern from a circle of onionskin paper and the image is a total blur. I guess the image is not focused until it hits the final display screen (duh).

Craig was right, the spherical mirror was off-center. (Actually it was too far down, but since the image at the CRT face is sideways, that caused the arc-shaped cutoff on the side of the final image.)

Today I reopened the optical box and reset both the spherical and 45-degree plane mirrors, using more care than before. Now the picture's pretty similar to what I had before I pulled the mirrors for resilvering (but brighter):

Image

I think the mirror installation is in the right ballpark, so now I can go through all of the mechanical adjustments, which may help things somewhat.

The picture looks bloomy on high-contrast content, as you can see in the animated .GIF. Poor HV regulation?

On the bad news front, it finally occurred to me to stick my head up into the display canopy and inspect the big (final) mirror. It looks crappy, with degraded areas like those seen on the 45-degree mirror before recoating. Silly me, I was thinking that being protected as it is from dust & whatnot, that mirror would stay pristine.

Removing that mirror means pulling out the whole sliding canopy, which is a task for another day.

Bottom line: recoating the 45-degree mirror was worthwhile, but it wasn't a miracle cure.

Phil Nelson
Phil's Old Radios
http://antiqueradio.org/index.html


Last edited by philsoldradios on Aug Sun 13, 2017 4:06 am, edited 1 time in total.

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 Post subject: Re: Emerson 609 projection TV restoration
PostPosted: Aug Sat 12, 2017 10:40 pm 
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I don't know what the Emerson's main mirror's size is, but when I worked at Magnavox on their 50" projection TVs in the early 1980s, the really big main mirror was reflective mylar stretched over a sturdy frame. Doggone things were within a few percent of the reflectivity of glass mirrors and weighed and cost much less. I wonder if you could adapt that idea to your Emerson?

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Mark Nelson
A collector of TV signal boosters and UHF converters -- God help me!
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 Post subject: Re: Emerson 609 projection TV restoration
PostPosted: Aug Sun 13, 2017 4:36 am 
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The viewable area of the screen is 12 x 16 inches, so I guess the big (final) mirror would be similar.

Speaking of that screen, I noticed that its wooden frame has slightly cracked open on one side. Consequently, that corner of the frame doesn't slide forward all the way when you lock the screen in viewing position. Which means the big mirror is slightly misaligned side-to-side.

In this photo, notice the bigger gap on the right side, between the screen frame and the control panel frame:

Image

I'll need to remove the canopy to fix the frame, and I was meaning to remove it anyway, to give the big mirror a close inspection.

Mylar is an interesting idea, although I'm inclined to have the big mirror recoated if its surface looks as bad as the plane mirror did.

Regards,

Phil Nelson
Phil's Old Radios
http://antiqueradio.org/index.html


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 Post subject: Re: Emerson 609 projection TV restoration
PostPosted: Aug Sun 13, 2017 2:21 pm 
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Location: Lafayette, CO
The final 45° mirror can be replaced with a normal mirror cut to size. Yeah, l know the difference between front- and rear-surface mirrors and why. Just might save a lot of money....slight if any viewable difference. Both mirrors in the Norelco box have to be bright. Problems with optics is one reason the early projection sets were not liked by technicians....and the picture was hard to keep crisp. Craig


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 Post subject: Re: Emerson 609 projection TV restoration
PostPosted: Aug Sun 13, 2017 8:22 pm 
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analog.tv wrote:
.... Problems with optics is one reason the early projection sets were not liked by technicians....and the picture was hard to keep crisp. Craig

I heard about that. A friend who is a long time repairer of almost any vintage TV you could name has not or will not touch early projection sets. They seem to be "labor-of-love" restorations!


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 Post subject: Re: Emerson 609 projection TV restoration
PostPosted: Aug Mon 14, 2017 4:10 am 
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OK, here is the canopy detached from the cabinet (not a fun process):

Image

The final mirror looks decent from a distance:

Image

But closer inspection reveals the same flaws that I found in the 45-degree plane mirror in the optical box. Cleaning the mirror didn't improve it:

Image

Two corners of the screen frame have popped loose. This rail would fall out if it wasn't held from behind by a screen mount:

Image

I'm inclined to send this mirror off for recoating. While it's away at summer camp, I can do cabinet refinishing & repair. Besides the screen frame breakage, the cabinet lid has a big circular boo-boo (someone's failed attempt at fixing a flowerpot stain), and there's a broken leg, too.

Phil Nelson
Phil's Old Radios
https://antiqueradio.org/index.html


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