#301
|
||||
|
||||
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.
__________________
John Folsom |
#302
|
|||
|
|||
could it be a transformer and not an autoformer?
|
#303
|
|||
|
|||
Quote:
I'm standing by to follow this saga. John, photos would sure be a treat for everyone. Last edited by Mal Fuller; 10-01-2011 at 03:49 PM. Reason: Improve layout |
#304
|
||||
|
||||
Quote:
From your description of the circuit, this second possibility seems less likely, but if this is indeed a CPA chassis, could the phase control function as a tint/hue control?
__________________
Chris Quote from another forum: "(Antique TV collecting) always seemed to me to be a fringe hobby that only weirdos did." |
#305
|
||||
|
||||
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
__________________
Evolution... |
Audiokarma |
#306
|
||||
|
||||
Phase if horizontal could refer to burst timing
Sent from my LS670 using Tapatalk |
#307
|
||||
|
||||
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 |
#308
|
||||
|
||||
Quote:
Cliff |
#309
|
||||
|
||||
Quote:
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. |
#310
|
||||
|
||||
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.
__________________
Evolution... |
Audiokarma |
#311
|
||||
|
||||
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...
__________________
Evolution... |
#312
|
||||
|
||||
Quote:
Cliff |
#313
|
||||
|
||||
I get 1 3/8" for outer diameter, not sure what the shell size should be. Steve McVoy sent one from a regular octal connector, it was too small.
__________________
Evolution... |
#314
|
||||
|
||||
Quote:
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). Last edited by Penthode; 11-29-2011 at 12:14 AM. |
#315
|
||||
|
||||
Quote:
I'll look some more but I doubt there's anything like that in my parts boxes. Cliff |
Audiokarma |
|
|