Videokarma.org

Go Back   Videokarma.org TV - Video - Vintage Television & Radio Forums > Early B&W and Projection TV

We appreciate your help

in keeping this site going.
Reply
 
Thread Tools Display Modes
  #31  
Old 07-28-2017, 11:54 PM
Tom Albrecht's Avatar
Tom Albrecht Tom Albrecht is offline
VideoKarma Member
 
Join Date: Mar 2010
Location: San Jose, CA
Posts: 604
That looks a lot better!
Reply With Quote
  #32  
Old 08-08-2017, 07:17 PM
Phil Nelson's Avatar
Phil Nelson Phil Nelson is offline
VideoKarma Member
 
Join Date: Jan 2006
Posts: 3,889
Sigh. I was full of hope when I reinstalled the recoated mirror, and then things began to go south. At first, the only problem was (still) bad focus, and when I changed one resistor in hopes of addressing that issue, the 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, as well as a pretty full recap (get it?) of what work I've done so far:

https://antiqueradio.org/Emerson609P...Television.htm

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

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[/url]

Last edited by Phil Nelson; 08-09-2017 at 01:13 AM.
Reply With Quote
  #33  
Old 08-08-2017, 07:35 PM
vts1134's Avatar
vts1134 vts1134 is offline
Looking For Time
 
Join Date: Apr 2011
Location: Pittsburgh, PA
Posts: 1,497
Hang in there Phil, this is the toughest phase of a restoration...pulling the chassis back out . We've all been there and it's no fun. Keep at it and you'll tame the beast!
__________________
John
Reply With Quote
  #34  
Old 08-08-2017, 08:21 PM
Eric H's Avatar
Eric H Eric H is online now
Administrator
 
Join Date: Jun 2002
Location: So. Calif
Posts: 11,307
At least the CRT looked like it was bright when it was working.

I have an RCA Projection set that I've kind of lost interest in, it's such a nightmare dealing with all the chassis's (Chassi?) in the darn thing, plus having to trying to carry the barrel along with the sweep chassis since they can't be easily separated.
Reply With Quote
  #35  
Old 08-08-2017, 09:47 PM
Crist Rigott Crist Rigott is offline
VideoKarma Member
 
Join Date: Oct 2015
Location: Waxahachie, TX
Posts: 1,056
Hang in there Phil. Your articles have helped a lot of people. I'm confident that you'll get it fixed and it will be working great.
Reply With Quote
Audiokarma
  #36  
Old 08-08-2017, 10:19 PM
old_coot88 old_coot88 is offline
VideoKarma Member
 
Join Date: Sep 2009
Posts: 1,864
Since both H and V sweep are reduced equally, seems like the fault would have to be B+ related and pretty easy to nail.
Reply With Quote
  #37  
Old 08-09-2017, 01:14 AM
Phil Nelson's Avatar
Phil Nelson Phil Nelson is offline
VideoKarma Member
 
Join Date: Jan 2006
Posts: 3,889
Check B+ . . . We hear and obey (tomorrow).

Thanks,

Phil Nelson
Reply With Quote
  #38  
Old 08-09-2017, 03:13 PM
Phil Nelson's Avatar
Phil Nelson Phil Nelson is offline
VideoKarma Member
 
Join Date: Jan 2006
Posts: 3,889
Ding-ding-ding! old_coot88 was on the mark, as usual. Broken lead between C6 and junction of M3/M4 in the Sams schematic, so no juice coming down that line.

Simple to diagnose (once you know where to look), and a big fat pain to fix. It will take 1/2 hour of horsing around to get all the heavy chassis out of the cabinet and back into the workbench, and about 1/2 minute to repair the break!

While it's on the bench, I'll be able to view the CRT face and judge the focus there.

Later,

Phil Nelson
Reply With Quote
  #39  
Old 08-09-2017, 04:31 PM
Electronic M's Avatar
Electronic M Electronic M is offline
M is for Memory
 
Join Date: Jan 2011
Location: Pewaukee/Delafield Wi
Posts: 9,196
If face focus is good, look into optical focus. There may be mechanical adjustments for it.
__________________
Tom C.

What I want. --> http://www.videokarma.org/showpost.p...62&postcount=4

Reading between the scan lines since the mid 2000's.
Reply With Quote
  #40  
Old 08-09-2017, 06:00 PM
Phil Nelson's Avatar
Phil Nelson Phil Nelson is offline
VideoKarma Member
 
Join Date: Jan 2006
Posts: 3,889
Yes, there are several mechanical adjustments, as the Rider manual shows in detail.

I temporarily reconnected the broken wire with a clip lead, which brought back the power supply 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:



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, such as the tilt adjusters on the base of the box. It's possible that some adjuster was seriously screwed up long ago, but the image that I got before resilvering the mirror was much closer to 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
Reply With Quote
Audiokarma
  #41  
Old 08-09-2017, 07:07 PM
old_coot88 old_coot88 is offline
VideoKarma Member
 
Join Date: Sep 2009
Posts: 1,864
This is a dumb question, but does the resilvered mirror have a protective film that needs to be peeled off?

The reason for asking is, I got skunked that way once with a new camera that was blurry til I figgered out what was causing it.
Reply With Quote
  #42  
Old 08-09-2017, 08:12 PM
jr_tech's Avatar
jr_tech jr_tech is offline
VideoKarma Member
 
Join Date: Sep 2009
Posts: 3,678
Is the mirror adjusted to be exactly 45 degrees to the optical axis?

jr
Reply With Quote
  #43  
Old 08-09-2017, 08:48 PM
Zenith6S321's Avatar
Zenith6S321 Zenith6S321 is offline
VideoKarma Member
 
Join Date: Aug 2010
Location: Piney Point, Maryland
Posts: 301
Quote:
Originally Posted by Electronic M View Post
If face focus is good, look into optical focus. There may be mechanical adjustments for it.
I agree, that with good focus on the CRT, the poor focus on the screen must be due to a miss-alignment in the optical path.

I have not worked on your projection TV model, but I have adjusted Barco projectors that have a Scheimpflug lens mount that allows you to adjust left-right and top-bottom optical focus. If you can tilt either the CRT face, the projection screen, or possibly the lens plane you may be able to correct the problem. See if you can find any mechanical adjustments that will let you tilt one optical element with respect to the others. I suggest you try to get good focus at the center of the image and then tilt the CRT, lens, or projection screen to adjust left-right and then top-bottom focus.

Dave
Reply With Quote
  #44  
Old 08-10-2017, 02:16 AM
Phil Nelson's Avatar
Phil Nelson Phil Nelson is offline
VideoKarma Member
 
Join Date: Jan 2006
Posts: 3,889
There wasn't any protective film on the resilvered mirror.

I didn't measure the angle of the plane mirror, so that's worth checking. There is very little range of movement for that mirror, once you have adjusted it so that the CRT is centered and clears the hole. There's a bit of elbow room, however. There are no adjusters for the spherical mirror, which is bolted perpendicularly inside the front wall of the box.

The manuals say nothing about installing or adjusting these mirrors, which was outside the scope of ordinary service, I guess. They must have used special jigs in the factory for this task. Due to X-rays, you can't loosen the mirrors and fiddle with them to watch the effect while the TV is playing, so the process might be tedious:

-- Make a little adjustment.
-- Close up box.
-- Turn on TV and view the screen.
-- Turn off TV and open the box.
-- Repeat as needed.

The manual does describe a bunch of adjusters for the optical system, including one on the corrector lens, but I don't want to mess with those until I confirm that the internal mirrors are installed as well as I can manage.

Phil Nelson
Reply With Quote
  #45  
Old 08-10-2017, 11:35 AM
old_tv_nut's Avatar
old_tv_nut old_tv_nut is offline
See yourself on Color TV!
 
Join Date: Jul 2004
Location: Rancho Sahuarita
Posts: 4,423
I think the optics should work in the reverse direction, so it would be possible to put a printed test pattern in place of the screen, illuminate it brightly, and observe the image on the tube. But probably not worth going there if there is little adjustment available.

I think I would continue to verify the internal mirrors are installed correctly and then move on to the described adjusters, as you say.
__________________
www.bretl.com
Old TV literature, New York World's Fair, and other miscellany
Reply With Quote
Audiokarma
Reply


Thread Tools
Display Modes

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off

Forum Jump


All times are GMT -5. The time now is 12:55 AM.



Powered by vBulletin® Version 3.8.4
Copyright ©2000 - 2018, Jelsoft Enterprises Ltd.
ęCopyright 2012 VideoKarma.org, All rights reserved.