Well, back to this...with some resolution, I guess. Today I decided to hook up my DVB tuner to my HLLY low-power transmitter and try to remove the pattern generator from the equation after another several hours of beating my head against this wall and blowing 30€ on sweep tubes. The HLLY is set for NTSC UHF channel 25, with standard 4.5MHz audio.
The DVB box has a unique feature in that you can switch its baseband output between PAL and NTSC, regardless of what the input format is. It plays MP4s from USB as well. So I set the box for NTSC, tuned in the PortaColor to UHF channel 25 and...exactly the same thing, jiggling picture. What a letdown. So it's not a problem with my signal source, this TV really is haunted.
OR IS IT?
I wanted to try changing some settings on the DVB box and the PortaColor was jiggling so much I couldn't even see the menu screen so I hauled out an old GEE (
that is not a mistake) B&W CCIR-B set that has a good picture on it and tuned the UHF tuner to the frequency of my transmitter. Jiggling like a MF. What? I could at least see enough to go through the menus and switch the output to PAL and the picture stabilized instantly. I didn't even have to adjust the holds.
So I hooked up my pattern generator (A Philips PM-5515TX) to the GEE set and jiggle city. I set the Philips back to PAL B, rebooted, and nice stable picture on the GEE. AARGH.
So, it is a problem with my signal source. Both of them in fact. Both of them are European products operating in a PAL world that let you set them to NTSC for one reason or another, and both of them exhibit exactly the same weird artifacts when used that way.
I'm at a loss for where to go from here. This is incredibly frustrating. Much of the frustration is of my own doing, I realize, wanting to working on these American sets instead of being content with the tons of Philips (and GEE!) that are here and were designed to work on the current and signals I have easy access to. But the heart wants what the heart wants.
I'm going to take a couple of days off and then see if I can get the PortaColor to produce a stable picture when fed a PAL signal. Color is another issue of course, but one thing at a time. I've also got a
mint Predicta Holiday I restored last summer sitting on a shelf because I thought I wired the power supply wrong and how much you wanna bet it's the same problem?