Prototype set is here

[John Folsom]

Nick, examine the HV winding on the flyback carefully. Often the failure is at one end or the other, where it might be possible to repair. Another option is I could wind you a new HV winding. Give me a shout if you want to discuss the possibilities.

[Mal Fuller]

Originally Posted by John Folsom

Nick, examine the HV winding on the flyback carefully. Often the failure is at one end or the other, where it might be possible to repair. Another option is I could wind you a new HV winding. Give me a shout if you want to discuss the possibilities.

Now there's an offer that Nick isn't likely to take a pass on. I'm very impressed to consider that the HV winding can be fabricated and replaced.
I'm standing by to follow this saga.
John, photos would sure be a treat for everyone.

[miniman82]

If it's CPA, there would be no need for a hue control since the CPA was meant to cancel out color phasing errors. It might be something to do with centering the video in the frame, but it has a proper centering control to center the actual scan so I'm not sure what to think at this point. If Ed would get off his duff and email me those scans I might have a clue...lol

[cbenham]

Originally Posted by miniman82

If it's CPA, there would be no need for a hue control since the CPA was meant to cancel out color phasing errors.

CPA works at the vertical rate, not horizontal. One field is one color phase and the second field is the other color phase. CPA was dropped because in it's simple form it produced bad flicker at the vertical rate. There were no 'one field' video delay lines available to solve the problem at that time.

Cliff

[old_tv_nut]

Originally Posted by cbenham

CPA works at the vertical rate, not horizontal. One field is one color phase and the second field is the other color phase. CPA was dropped because in it's simple form it produced bad flicker at the vertical rate. There were no 'one field' video delay lines available to solve the problem at that time.

Cliff

Very true. The problem was that the NTSC system was not true constant-luminance because of the CRT non-linearity. (Current digital TV systems are not constant-luminance either.) What this means is that the chroma signal can affect the brightness of a color (more so for saturated colors, not at all for grays).

It's the chroma flicker translating into luminance changes that is visible. During the development of HDTV, Dr. Schreiber at MIT proposed going to a true constant luminance system, and demonstrated that 30 Hz true chroma-only flicker (or even 15 Hz!) is invisible. This could hypothetically be used to reduce the frame rate of chroma to save bandwidth, but would run into problems when the camera pans or the eye tracks a moving object. It also could be used to more crudely encode the chroma without producing visible artifacts.

[miniman82]

Finally got around to making a base cover for the HV rectifier, now maybe it won't break so often from bouncing around. It's just a section of poly that I cut from the center of an old wire spool, I was gonna use a pill bottle but couldn't find one the right diameter.

[miniman82]

Tom C. found the plug I need for the filament string in this chassis, I hope to have it in my possession by the end of the coming week. Now, if only I could source a backshell for the other plug...

[Penthode]

Originally Posted by old_tv_nut

It's the chroma flicker translating into luminance changes that is visible. During the development of HDTV, Dr. Schreiber at MIT proposed going to a true constant luminance system, and demonstrated that 30 Hz true chroma-only flicker (or even 15 Hz!) is invisible. This could hypothetically be used to reduce the frame rate of chroma to save bandwidth, but would run into problems when the camera pans or the eye tracks a moving object. It also could be used to more crudely encode the chroma without producing visible artifacts.

The thought of true constant luminance is intriguing. Unfortunately, the benefit of transmission noise suppression in the blacks would be lost as the gama curve happily compensated for it. Not to mention the complication of adding a CRT compensation circuit at the receiver and having to reconcile some sort of backward compatibility if a fully constant luminance system was achieved.

With regards to the hue control critical adjustment, I recall working with "Simple PAL" receivers. The Delay PAL Monitors in the BBC studios had a simple PAL switch. It was great for checking PAL chroma subcarrier phase because an out-of-phase condition would yield "Hannover Bars". Each alternate line would have a noticable hue difference and even a slight phase misadjustment was very annoying. I would certainly prefer to see a noticable NTSC IQ system overall hue error to having to put up with the Hannover Bars. And this was the UK systems which allowed fully symmetrical upper and lower chroma sidebands which should eliminate the quadrature crosstalk problem! (Remember the UK channel was 8MHz wide with the sound carrier at 6MHz instead of 5.5MHz for their continental cousins. This allowed full +/- 1.5 MHz chroma bandwidth).

CPA was chosen as a means to help widen the chroma bandwidth (hence chroma resolution) and the Phase Alternate Line or Field was to help cancel the quadrature crosstalk resulting from the highly non-symmetrical chroma channels. Even with the hue control set to minimize the flickering, the flickering I would expect to be very noticable. In fact I would guess the hue control adjustment to be more critical for CPA than the later IQ system. It is which ever suits you: a slightly wrong overal hue versus a maddening flickery picture. (I, of course, use the term "hue" control loosely: it is the subcarrier phase adjustment I am referring to).

[old_tv_nut]

Phase if horizontal could refer to burst timing

Sent from my LS670 using Tapatalk

[Phil Nelson]

I guess you already have enough cabinet choices, but I thought of your prototype when this popped up on the local CL, as its grille resembles the CT-100 cabinet. It's much too shallow, however -- lacks about 6 inches.

Phil Nelson

[miniman82]

Was watching TV the other day, and noticed A&E is advertizing the new 'Shipping Wars' show. This is the series that Roy told me was filming him at the time the set was delivered, so start setting your DVR's in case I appear on screen!

http://www.shippingwars.net/

http://www.youtube.com/watch?v=yV6CTqduv-I

[tubesrule]

Hey Nick, you're a TV star!

You were just moments ago on the new Shipping Wars show. Hopefully you were recording it. They showed picking the set up from Harry just before the break and then delivering it to you. Very nice.

Darryl

[Steve D.]

Shipping Wars also airs overnite Wed. in the early AM. Airs again this Saturday at various times in the afternoon. This on A&E HD and standard networks. Check your cable listings.

-Steve D.

[kvflyer]

Originally Posted by Steve D.

Shipping Wars also airs overnite Wed. in the early AM. Airs again this Saturday at various times in the afternoon. This on A&E HD and standard networks. Check your cable listings.

-Steve D.

Just checked here on the east coast, supposed to be at 11PM both SD and HD. I set the DVR to record...

[Eric H]

Judging by the trailer I wouldn't let them touch anything of mine!
They might smash something just to spice things up.

Real life is nothing like these "Reality" shows.