CROSS Pattern Line Width

[chf1971]

Hello -

Philco Predicta Debutante Television Set

While injecting at the first stage of the Video I.F. section of this TV set, the CROSS Pattern from a SENCORE VA-62 displayed on the screen appears to have a wider Vertical Line than the Horizontal Line.

The DOTS pattern appears on the screen as "dashes" more so than "dots".

Two images, attached.

Can you provide any suggestions of what area of the set to suspect for this display issue ? Are their other test patterns which show this defect or alignment issue ?

[Electronic M]

Put a circle on screen and let's see how it looks. It's probably one of 2 things: more likely width is excessive, less likely video/IF smear.

[chf1971]

Thanks for the reply.

I should of provided some History of the TV Set.
I received it in Original un-touched condition.
On the Main Circuit Board all of the Couplets have been replaced with new Couplets received from "The TVrestorer guy ". On the MAIN Board, several of the Film Cap's in the Vertical Section have been replaced. Only the Couplets have been replaced in the Horizontal Section. Unit's Primary Power Supply Filter Electrolytics have been replaced. Vertical Linearity Potentiometer has been replaced. Video I.F. Board is still all Original. Thus, I suspect that the Horizontal Section can have out of tolerance caps / resisitor components. The Focus Adjustment's, nor any real Alignment Procedures have Not been performed.

Thank you for any of your suggestions.

[Kevin Kuehn]

Wouldn't hurt to try focus and fine tuning.

[chf1971]

THANK YOU for the replies.

Three points provided : Tuner, Test Equipment and Focus.
The TUNER has not been tested. Wait, I did try it one time and it was a use-less test. The Tuner has been disconnected. It needs to be removed, cleaned, evaluated, tested.
The TEST EQUIPMENT - SENCORE VA62 - Highly Likely To Be A Suspect. I have never verified the particular waveform performance of this SENCORE.
FOCUS - It's been a long time since I really was into or onto a CRT.

[Kevin Kuehn]

Sorry I didn't read your initial post very well where you clearly stated you were injecting signal at the video IF. Definitely test the Sencore on a known good TV so you at least have a baseline. Also that Predicta probably has a fixed focus voltage so it's not too likely the issue. Your VA 62 has a video output so you could bypass the IF stage all together and inject video to the video amp grid.

[old_tv_nut]

What does regular program material through the tuner look like? Any indication of this smearing? (Hope the tuner isn't dead.) (Trying to guess if the signal you are injecting is somehow wrong level,or if AGC is bad or who knows what.)

[old_tv_nut]

To me iot looks blurry both horizontally and vertically, so maybe a CRT focus issue?

[chf1971]

Philco Predicta Debutante

Most recent changes : few horizontal discrete ( film caps and resistor ) replacements. More adjustments of external controls : Horiz. Hold, Horiz. Frequency, Width, Height, Vertical Linearity, Brightness, Contrast, and Vert. Hold. Very slight adjustment of Horizontal Centering on the Yolk, however, repositioned this back to original position.

Video available of TV Program.

Cross Pattern from Sencore VA/62 analyzer.

Tim on tv show “ Tool Time “ shown - attached - on this Predicta Débutante.

chf1971

[chf1971]

Yes, the TUNER.
It is the VHF only one. No UHF. I was quite hesitant in removing and working on this , seeing that only VHF channels 03 - 04 would be used for the remote DTV converter or VHS / Beta deck.

Slow hours cleaning and lube. TUNER.
Light engine degreaser on tough spots , mild dish soap and H2O , 99 % isopropyl throughout. Lube / Clean w/ CRC QD Electronic Cleaner followed with CRC 2-26 Lubricant.

Channels 03 / 04 verified operational with DTV converter set top box / O.T.A. Programming Received.

[Notimetolooz]

I would not use engine degreaser. Any oil on the tuner chassis helps avoid rust and corrosion. You don't want to overdo cleaning. especially in areas that it does not effect performance.

It occurs to me that Predictas have a plastic cover on the CRT front.
Is this plastic clean and in good shape?
There could be deterioration and/or mold on it.

Your VA62 needs adjustment, but it is a very complicated unit. Probably more needed than just adjusting the line width. I'm saying that if one adjustment is off there could be other adjustments to check controlling other test outputs.

[chf1971]

Originally Posted by Notimetolooz

I would not use engine degreaser. . . .
It occurs to me that Predictas have a plastic cover . . .
Your VA62 needs adjustment, but it is a very complicated unit. Probably more needed than just adjusting the line width. I'm saying that if one adjustment is off there could be other adjustments to check controlling other test outputs.

Agree. Yes. Definitely Agree.

[Penthode]

Did you adjust the fine tuning for brightest picture or best detail before the noise creeps in? The carrier is to sit at 50% of the Nyquist slope.

In this age of digtal televisio and digital compression, the tuning to 50% on the slope on one side of the response is for vestigial sideband reception, a bandwidth saving technique. the trade off was a loss of 3dB signal to noise to get more picture detail though a narrow channel.

It seems that many of the younger folk are not aware of this and I am curious if you have adjusted the fine tuning correctly for best picture detail?

[Kevin Kuehn]

If you ever run across a tuner that has an RCA phono plug connection as the IF output, make sure to verify that connection is solid, including the center pin. Often the outer portion is so solid and yet the center loosens from constant vibration from changing channels. I recently about drove myself crazy trying to track down an intermittent noise disturbance that I assumed was dirty tuner contacts, because bumping the channel would usually bring the signal back. Finally after cleaning and retentioning that center socket on the IF phono jack the problem was solved.

[chf1971]

Two Video's link -

https://drive.google.com/drive/u/0/f...bwmC6gf1L4Syyy

Access permission / required.