Bravo, nice work. Good to see progress on this one.

The 6LF6 will be expensive but most likely. The other tubes have
no other uses so should be much less. It depends on if you
want to possably wait & pay another shipping charge etc.

73 Zeno:smoke:

Drummonville is near me but I live on the other side od the St-Laurence river..:thmbsp: However, the link is dead. I mean ..non disponible

Of course the link is dead, this thread is 1.5 years old Haha.

Sorry , you where closer to it, but I was faster ;)

No problem :D :thmbsp:

Had ONE_-back in about this time of 1988. It even had a built-in stand. Found it "shopping' on a SNOWY night.


Got it running (can't remember what was wrong...maybe NOTHING..) and sold it--back then, $ 50 or so was decent gas/food money for me.

It's not quite a "tabletop console". Like RCA2000 said , it's a pedestal set. Here's a complete picture of it. I prefer the look of the tv without the stand myself, but i'm not going to throw it away because of it historic "value" :)

magnavox made a pedestal set also.this is a very nice,rare set.hybrid zeniths produced the very best picture.we had several hybrid 19 inch sets and they sold quickly because of the fine picture.newer,solid state sets were passed by because of the picture quality.zeniths blew them away.i would love to have this set!

So, a bit of an update. I went ahead and ordered the 4 tubes that where in the set : 6LF6 (that I substitued for an 6LX6, because the 6LF6 price was stratospheric) , 6U10, 6DT3 and 6JA5. As soon as I replaced them I noticed 2 immediate effects :
- My light pull on the right disappeared!
- Convergence went A-wall...

So after a bit of trying this trying that I arrived at a pretty good result with the convergence.

Now 2 problems I have :

Firstly, those lines at the top of the screen are still there ,and they don't go away after the sets warms up. (see picture 2). They seem to fade in, and then fade out...

Secondly, and that is a very minor problem, color seems to have trouble syncing when I power up the set. I have to rotate the VHF knob ever so slightly and they come back.

One minor observation, is it possible that Delta gun crt, even very good one like the chromacolor, are not capable of producing a picture as sharp as an inline tube? I think the sharpness on my chromacolor is OK, but it can't hold a candle to my cheap 1986 hitachi.

Thanks!

fade in fade out lines, macro vision copy protection.

good convergence/good CRT/should make a nice sharp pic. May not be able to get convergence perfect on edges, but still should be sharp where it is converged. Does the focus adj take you in and out of focus, or does it run out of range (best focus is achieved with the pot turned to fully CW or CCW)?

I had a recent CC that needed a new focus divider to get the range under control to where I could focus precisely.

I happen to KNOW....a good chromacolor set can outdo about ANY in-line tube...PERIOD !!

Chromacolor II zenith sets had about the BEST overall color picture. About the only thing better in overall color picture (but NOT brightness of course) is a Zenith ROUNDIE

It looks more like vertical under scan allowing the Closed Captioning data to be visible to me. Can you play a program that is not letter boxed and look for under scan?

First off the set is probably a "Super Chromacolor" an
improved chromacolor.
chromacolor II sets were the next year sets with upright
solid state chassii. ( 19EC45 etc).

Lines are from the CC or other "new" add ons to the signal.
They were not around when the set was new, 99.99% was
off air or cable then.

By nature small screens look sharper. With a perfect set-up &
CRT your set will give a very detailed picture for its time. BUT they
can not run at the brightness & contrast of in-lines without
loss of some pix quality. The set also has a sharpness control on
the rear. Often the little white knob goes missing but its the
common size.

The color I assume is "barber poling" before locking in.
First clean the NORMAL -ALIGN switch on top of chassis.
Then put into ALIGN. On the 9-27 module there are 2 controls
ACC & APC. Adjust the control so you get the least amount of bars
or the tint slowly changes. Go back to NORMAL & try it.
If it still gives trouble you can pull the 9-27 module & clean
the IC & socket carefully. Not the way it came out & use an insulated
screwdriver to adjust !! Also spray the module contacts.

73 Zeno:smoke:

OOPS
Adjust the APC control only.

Can you tell me which one is the APC?

Also, I took a picture of the geometry of the screen, I can't seem to be able to ajust the picture to get it to fill the whole screen without stretching/deforming it.

As for the sharpness, maybe I went too far in saying that it can't hold a candle to my cheap Hitachi, I don't want to upset you guys :D But I feel it is a bit lacking. As for the focus pot, it is almost maxed out. Just before the last 1/16 turn adjustment the focus seem to get worst...so I guess the range is still there...somewhat, but for all intent and purpose it is almost 100% full ccw.

thanks!

You definitely have vertical under-scan at the top and bottom. You need to readjust the vertical height and linearity (and possibly centering).

as long as you can get to a point where the focus gets best and then continuing to turn gets bad again then you have a usable range. but as you noted you are almost out of range. I opted to replace the focus divider on mine to get it back more near the center. Sometimes the pot itself becomes an issue with dirty or worn spots making careful adjustment a problem. You can swap the ends around on the pot to get to a better unworn out part if you want to try that.

Dont remember witch is APC but.
The 9-27 almost always has a shield over it with 2
holes & a sticker showing the controls. Also look
on the layout.
If you dont find them I can dig up tomorrow.

Vert size pots ( 63-9115 ) always got bad spots.
We bought strips of them but you can also usually
clean them.

73 Zeno:smoke:

I've got a 1971 Zenith 'more than 4' tube hybrid. The focus divider was drifty on mine and the pot was hitting the stop before getting proper results. I figured I could not find a divider and the circuit was simple, so for the first year or two I just added 4.7 Meg (IIRC) resistors (each time optimal focus went outside control range) until there were about three in series with the focus divider. It has been stable with sharp focus in range for a few years now, and it gets a lot of use.

...

that was the prob on mine, could not go low enough, even shorting the 4.7 meg would not get me there.

I have a plastic cabinet tabletop 19DC12 and my focus pot is in the "vert centering" apron hole as well. I thought it was an upgrade mod.

I also had a 19DC11 set that was otherwise identical and had the divider resistor like Tom's earlier set. The focus control was mounted on a fiberglass board at the fly and the control had a long shaft that stuck out the back.

As I recall, the focus was better on the 19DC11 but I gave it to Bryan Gadow in one our frequent set-swaps.

IIRC the ones with the glass board all had a big disc cap that would arc.
The caps were pulled & a tripler kit subbed. The original tripler was
a weird looking thing like a ladder & was red. Not too many
came that way. There were a lot of varieties in the hybrids HV.
I only did one FBT on one & it was a big kit & included a tripler
IIRC.

73 Zeno:smoke:

Ok, now I located the 9-27 board. Before I went to adjust the APC control, I went and change the DVD in my player to put back my terminator DVD that has the THX pattern...and that was the last time my TV was able to lock in on the signal that was feed via the RF modulator. Now not only the color won't lock in , but the whole picture won't (see picture).

That occured while the TV was on, and I didn't even touch the TV between the dvd swap...it was ok...then it went bongo.

I tried a different RF modulator, tried to lock the signal by turning the VHF tuner...nada.

At least I have great colors now :P

Looks like a complete loss of horizontal sync. Perhaps that tube you subbed in was not suitable.

Possible, but I replaced every tube with same number ones and it worked fine for a couple hours... I will try to sub some of the old ones to see.

Its the hoz hold on rear, white knob. If its at the end
you can pull back the the sleeve to move it more.
Change channels back & forth when setting so it
syncs right in. Its a coil so it can turn many times.
The lines will get father apart as you go in the right
direction.
Only tube that can do it is the 6U10.
If the horz is near falling out of sync it can cause
color sync probs also.

73 Zeno:smoke:

I've seen that trippler and I understand that it was a Selenium stack and German made. I omly saw one Zenith that used it. :scratch2:

Oh, I thought you subbed a different tube due to high cost.

So, finally it only was the horizontal Hold that made the fuzzy picture, everything works now. I redid convergence, and now it got a good picture! I am still not 100% blown away by it as much as I thought I would be, but its definitly is a drastic improvement from where I began.

Now, there are the small issues of : Jail bar, and of course getting rid of that pesky macrovision buzz and color lines! Anyone knows a good macrovision filter? I bet this could get handy with pretty much all the sets made before 1980 or something...?

I did, but the subs where also marked as alternative right in the back cover of the TV. By the way, what would be the effect of replacing an 6LX6 by a 6LF6 other than it would have cost me twice as much haha?

The sub makes no difference. IIRC all Zenith came with a
6LX6 or 26LX6 on series sets. Only other sets I recall were
Motorola hybrids came 6LF6 or 20LF6. Others probably used it.
I dont remember on Motorola but Zenith can sub 20LF6 for
26LX6.

Price difference probably due to most hoz outputs are used by
hams for amplifiers One tube probably has specs that are better
so more demand.

73 Zeno:smoke:

Good morning everyone,

So in the light of the thread about my newly aquired flatchassis, I decided to go back to my hybrid and redo convergence with colors off to see if I could improove things a bit. What bothers me with my hybrid is the same thing that bothers me with my flatchassis : Both got great colors, but I think that the picture is washed out, and color is blooming even if convergence is accetable. So this time I did a side by side comparaison shot with my daily watcher (1986 Hitachi console).

Here's are the results. Picture 1/2 crosshatch pattern colors off/on on my hybrid, picture 3 and 4 are comparaison shot hybrid/Hitachi. You will notice how much sharper the text is on the Hitachi. I did ajust the focus on the hybrid more than once to make sure it was spot on.

At this point, I wonder if it has anything to do with bad convergence at all...could it be chroma bandpass as Electronic M said in the flatchassis thread?

That blush of color in the lower multi-burst pattern shows the color circuits reacting to what should be a monochrome signal. It would be interesting to know the frequency at which this is occurring. It could be alignment issues or it could be a design limitation of the set lacking a comb/notch filter.

A notch filter is only applied to luma, never to chroma (it would eliminate the color signal from the color circuits!). So, you are seeing the expected effect with a notch filter set, with luma in the color bandpass showing as flickering color.The short shutter time used for the picture captures one phase of the cross color instead of averaging it out, making it look worse.

In both shots (color on and color off), the black level (don't know if it's labeled "brightness" on this set) is set too low. This makes the darker gray scale chips all look black, and may have prompted the chroma to be turned up too high to bring up the red and blue bars, also increasing the visibility of the cross color.

I tried, various setup of brightness/contrast , and it is true that higher contrast (lower brightness) seems to help a bit, but the worst offender here is the "color" ajusting. I can get the color where it's not blooming that much anymore...but the picture gets very dull (not much colors).

Could it be that, a mix of cheap RF modulation and macrovision fed to a television that wasn't desing to receive and process that kind of signal could "degrade" the picture like that? How do you guys with roundy go about to get the very best image on your sets?

Oh and BTW, I am still not getting any snow when the TV receive no signal, only a white uniform picture. Could it give a clue to what's wrong?

Thanks! :scratch2:

I'd like to help you with that, but it could be a while until I get my hand on the required equipment to do so.

Lack of snow with no signal is completely separate from your color issues - I'm only going to talk about color setup:

You say that lower brightness "seems to help" but from your pictures the "brightness" (or "black level," not "contrast" or "picture") is too low already. You should see uniform steps in the gray scale with only the darkest one being black. Secondly, your complaints about color being washed out tell me that you are looking subjectively for uncalibrated overly saturated color. To get (approximately) calibrated color, you first need to get the gray scale correct, then view the color bars through a blue filter and adjust hue (tint) and saturation (color) to get all the blue-containing colors to have the same amount of blue (looking the same through the blue filter) as shown on this page:
http://www.spearsandmunsil.com/portf...r/#prettyPhoto

My guess from your comments is that you will not like this accurate setup, but at least it gives you a known starting point for adjusting towards your preference.

A few things.
Looking at you pix if its accurate its a little purple.
Try adding just a little green.
The pattern looks pretty good. The bottom bar is for
resolution & looks normal. If the set had a comb filter
the blue wouldnt be as bad & you would see more
lines to the right of it ( the high freqs for detail ).
The CRT looks just a tad weak. You cant always go
by the checker for that. I never harmed anything
with the clean & balance so maybe try that.
The Hitachi probably has a comb filter, most mid to high
end sets had them by the mid 80's. Thats much of the
reason for better small white lettering.

BTW Did we cover the HV control on this yet ??

73 Zeno

You don't need equipment (although some equipment can do that)...Just a DVD with a multiburst pattern that bothers to label the frequency of the burst bars on the pattern. If that pattern just had some labels it would tell me a lot about what is happening.

No need for labels or further tests - it is at the color subcarrier frequency, just as it should be. You can also see the notch in the luma response in the monochrome picture.