Videokarma.org TV - Video - Vintage Television & Radio Forums

Videokarma.org TV - Video - Vintage Television & Radio Forums (http://www.videokarma.org/index.php)
-   Early B&W and Projection TV (http://www.videokarma.org/forumdisplay.php?f=19)
-   -   My new predicta (http://www.videokarma.org/showthread.php?t=257661)

josephdaniel 03-17-2013 04:24 PM

My new predicta
 
1 Attachment(s)
I just got home and as soon as I got out of the car I gave it a much more detailed look and I saw modern capacitors underneath the set so I pulled out the chassis and someone replaced all if the caps underneath but not on the board!!
On the pc board everything was original and there were two black beauties that were cracked. After all if this I decided since most if the components had been replaced it would be reasonably safe to power it up I got good sound but it was a little weak and no raster I suspect a cold joint in a tube socket since I saw a raster when it was in the mall but I didn'ta leave it on long enough to warm uphttp://img.tapatalk.com/d/13/03/18/ja8y7e9e.jpg.
Attachment 178119

http://img.tapatalk.com/d/13/03/18/a8agu2yv.jpg

mpatoray 03-17-2013 09:44 PM

Congrats on the new Predicta!

Check out Bob's series of videos on the Predicta Holiday. A LOT of good tips in there and how to deal with the early PCB's and the cuplates.
http://www.youtube.com/playlist?list...2y62xYCp5PgZx_

Dude111 03-17-2013 09:49 PM

Good for you my friend :)

StellarTV 03-18-2013 02:56 AM

Wow, not only a great price but so much work already done for you!!

Makes me wonder where the set came from... it might be interesting if you get a chance to talk to the dealer and ask them the backstory.

josephdaniel 03-18-2013 07:42 AM

I would like to know its story and why the person stopped working on it. Hopefully they dident discover that some unobtainun part wasn't fried like the flyback or CRT

bandersen 03-18-2013 10:52 AM

Looks like it has the original thermistor and filament dropping power resistor. Often one or both of those are bad.

josephdaniel 03-18-2013 10:56 AM

The thermisistor is good but I don't know what the dropping resistor shops measure at on my ohm meter?

josephdaniel 03-18-2013 11:00 AM

Also what should the voltage readings be on the pins of the CRT?

bandersen 03-18-2013 12:38 PM

You can download the Sams service info for free here: http://www.earlytelevision.org/tv_sc...s_postwar.html

josephdaniel 03-18-2013 12:44 PM

Thanks! That will be a lot of help when I get into the set more.
So do you guys think when I pull the PCB I should rebuld all of the networks that seem to go bad frequently and all of the resistors as a precaution?

StellarTV 03-18-2013 02:22 PM

I wouldn't rebuild the networks unless you really want the practice. If you'd like to tackle one, which in my opinion is the worst offender and also the simplest to build, tackle the vertical integrator, which is the short 4 pin network next to the vertical output.

Geist 03-18-2013 02:58 PM

Hi All;
Joseph, Bob Andersen, has in His Predicta Video's, about How He rebuilt His Integraters.. Check it out And then decide..
THANK YOU Marty

josephdaniel 03-18-2013 03:05 PM

Quote:

Originally Posted by Geist (Post 3064699)
Hi All;
Joseph, Bob Andersen, has in His Predicta Video's, about How He rebuilt His Integraters.. Check it out And then decide..
THANK YOU Marty

I will. I was just thinking that since the boards are so hard to remove in these that I would just do them all while it was out since they seem very failure prone. Has anyone actually opened up one of these networks to see what exactly is inside?

bandersen 03-18-2013 03:36 PM

Yes, I did at some point in the videos. Some are just encapsulated discrete components (carbon comp resistors, ceramic caps, etc). Other networks (vertical integrator) are made from carbon and metal deposited on a ceramic substrate.

Here's my restoration thread in case you haven't read it yet:
http://www.videokarma.org/showthread.php?t=255328

josephdaniel 03-18-2013 05:02 PM

If the video output tube (6aw8a) is gassy or dead would that cause the screen to be completely dark I just looked at this tube with the set on and it is very purple inside when on so is the horizontal output tube.
I have determined there is HV but I don't have a probe to measure the exact voltage but I can get a 1/2 centimeter spark to the housing of the flyback transformer.


All times are GMT -5. The time now is 06:01 PM.

Powered by vBulletin® Version 3.8.4
Copyright ©2000 - 2026, Jelsoft Enterprises Ltd.
©Copyright 2012 VideoKarma.org, All rights reserved.