atkelar | Restoration Project #26: TV Test Pattern Generator @atkelar | Uploaded June 2021 | Updated October 2024, 16 hours ago.
I'm getting deeper and deeper into old technology; some of which involves CRT TVs in one way or the other. To adjust these after taking them apart for cleaning and generic fun, it is useful to have a test pattern - or reference signals. I kept searching on e-bay and other sites to see if something interesting pops up. And most modern, cheap devices that make test patterns are either digital or "single standard", so they would force me to buy two devices: one for PAL and one for NTSC, since I expect to end up with both types of TVs eventually. When this Philips unit popped up in the search result, I just couldn't resist!
I took it through the usual paces: clean inside and out, recap the electrolytics and read the EPROMs. It might have been the time constraint I put up for myself or just bad luck but there were several things going wrong:
First, two of the push buttons - which were heavily oxydized - didn't survive the process; the "dome" somehow lost its "spring". Good thing there are extra ones in this unit that would be used for the stereo and/or teletext version.
Second, I read and archived the two EPROMs... and promptly installed the main program one backwards. I almost burned my fingers on that one. Much to my surprise however it still is working just fine! Built like a tank indeed!
Third, I didn't notice that one of the transformer core plate pieces was at an angle when I mounted it. That piece of sheet...metal was interfering with the encoder switch to select the TV standard, acting almost as a one way latch. I was close to using brute force on that poor switch.
I am still waiting to see if a vectorscope comes along, so I can finish the adjustments on the color signal... and a frequency analyzer for the RF part... The voltages seem OK and my modern LCD TV shows nice colors... but this is supposed to be a reference signal, so I better get it as close to the specs as I can!
0:00 Intro
1:13 Disassembly
2:11 Battery and Service Manual
4:54 Regular Potentiometer Cleaning
6:29 HF Potentiometer Cleaning
7:40 Capacitor and Battery Replacements
9:02 Front Panel Buttons
10:12 EPROM Socket (Factory) Oops / First Assembly Steps
11:10 Turn On / Supply Rails / EPROM Orientation (My) Oops
12:33 LED Adjustment / Front Panel Fix / Test Program
13:14 Output Test and First Picture! / TV Standard Encoder Problem / Alignment
14:25 Case Finalizing
15:38 Completed! / Credits / Outtakes
Music:
My Train's A Comin'
Unicorn Heads
(YouTube Audio Library)
You can support me on Ko-Fi: ko-fi.com/atkelar
I'm getting deeper and deeper into old technology; some of which involves CRT TVs in one way or the other. To adjust these after taking them apart for cleaning and generic fun, it is useful to have a test pattern - or reference signals. I kept searching on e-bay and other sites to see if something interesting pops up. And most modern, cheap devices that make test patterns are either digital or "single standard", so they would force me to buy two devices: one for PAL and one for NTSC, since I expect to end up with both types of TVs eventually. When this Philips unit popped up in the search result, I just couldn't resist!
I took it through the usual paces: clean inside and out, recap the electrolytics and read the EPROMs. It might have been the time constraint I put up for myself or just bad luck but there were several things going wrong:
First, two of the push buttons - which were heavily oxydized - didn't survive the process; the "dome" somehow lost its "spring". Good thing there are extra ones in this unit that would be used for the stereo and/or teletext version.
Second, I read and archived the two EPROMs... and promptly installed the main program one backwards. I almost burned my fingers on that one. Much to my surprise however it still is working just fine! Built like a tank indeed!
Third, I didn't notice that one of the transformer core plate pieces was at an angle when I mounted it. That piece of sheet...metal was interfering with the encoder switch to select the TV standard, acting almost as a one way latch. I was close to using brute force on that poor switch.
I am still waiting to see if a vectorscope comes along, so I can finish the adjustments on the color signal... and a frequency analyzer for the RF part... The voltages seem OK and my modern LCD TV shows nice colors... but this is supposed to be a reference signal, so I better get it as close to the specs as I can!
0:00 Intro
1:13 Disassembly
2:11 Battery and Service Manual
4:54 Regular Potentiometer Cleaning
6:29 HF Potentiometer Cleaning
7:40 Capacitor and Battery Replacements
9:02 Front Panel Buttons
10:12 EPROM Socket (Factory) Oops / First Assembly Steps
11:10 Turn On / Supply Rails / EPROM Orientation (My) Oops
12:33 LED Adjustment / Front Panel Fix / Test Program
13:14 Output Test and First Picture! / TV Standard Encoder Problem / Alignment
14:25 Case Finalizing
15:38 Completed! / Credits / Outtakes
Music:
My Train's A Comin'
Unicorn Heads
(YouTube Audio Library)
You can support me on Ko-Fi: ko-fi.com/atkelar
