View Full Version : Zenith Integrators


Zenith26kc20
03-09-2014, 02:07 PM
From what I can see, the integrators (87-5 is the one I need) are made of five parts. Two resistors and three capacitors. I have the values and they appear to be made up of ceramic disc capacitors. Has anyone made the vertical one? The resistive portion should be 94K ohms (2) 47K resistors in series). Mine measures 225K ohms and I cannot achieve full sweep. I have about two inches of black on the bottom of my 25MC33 Zenith.

zeno
03-09-2014, 03:15 PM
From what I can see, the integrators (87-5 is the one I need) are made of five parts. Two resistors and three capacitors. I have the values and they appear to be made up of ceramic disc capacitors. Has anyone made the vertical one? The resistive portion should be 94K ohms (2) 47K resistors in series). Mine measures 225K ohms and I cannot achieve full sweep. I have about two inches of black on the bottom of my 25MC33 Zenith.
Never made one up, twas a stocked item. One end of each cap
goes to ground (center leg) other ends go to each resistor ( end legs)
& one to the resistor jcn.

73 Zeno:smoke:

Eric H
03-09-2014, 05:31 PM
I made one when I was messing with my Flashmatic trying to get the vertical linearity right, if I remember right the integrators made very little difference in the picture, even if you left them out. I never did get it working exactly right and wound up fudging the Cap values elsewhere to get an acceptable picture.

reeferman
03-09-2014, 09:16 PM
I worked on a lot of Zeniths and what you describe is the classic failure symptom.
I would automatically change them, bad or not.

Zenith26kc20
03-10-2014, 08:19 AM
biggest problem is I'm five days away from getting back to the set!!!!
Patience is a virtue I guess!

Kamakiri
03-10-2014, 08:46 AM
Here's a thread that I had on my '61 Zenith that used them, we discussed the integrators a bit:

http://www.videokarma.org/showthread.php?t=258080

dieseljeep
03-10-2014, 10:27 AM
I worked on a lot of Zeniths and what you describe is the classic failure symptom.
I would automatically change them, bad or not.

The replacements were a lot better quality, than the originals.
I don't know why Zenith made their own caps! It seems like an inexpensive item to purchase, instead of having to maintain plant space. I know that the disc capacitors were usually duals, but they didn't even look good. Poor value stamping and they always looked like they were cracked. :sigh:

Zenith26kc20
03-10-2014, 01:03 PM
got the parts in my pocket. Two 1600 volt caps and one 630 volt. Got the resistors too! Going to put them in the truck and WAIT......
Bah!