Motorola ts907 low hv

[timmy]

I realize that maybe I’m causing high current draw on the pic tube since I have all 3 g2 pots at max but the g1 is low.

[Electronic M]

Originally Posted by timmy

It’s got to be shorted because it gets hot rather quickly and if I lower brightness alittle the hv comes up

Originally Posted by timmy

I realize that maybe I’m causing high current draw on the pic tube since I have all 3 g2 pots at max but the g1 is low.

That could darn well do it. G2s should be set with contrast normal, brightness minimum, vertical sweep disabled (using service switch if there is one), and set G2 so associated color produces a barely visible horizontal line in a dim room. If G2s achieve that at lower in their rotational range and you crank them up above their correct setpoint you'll lug down your HV, and focus, and probably strain the heck out of the flyback making it heat up.

[timmy]

Originally Posted by Electronic M

That could darn well do it. G2s should be set with contrast normal, brightness minimum, vertical sweep disabled (using service switch if there is one), and set G2 so associated color produces a barely visible horizontal line in a dim room. If G2s achieve that at lower in their rotational range and you crank them up above their correct setpoint you'll lug down your HV, and focus, and probably strain the heck out of the flyback making it heat up.

Well this is a Motorola with no service switch I’ll have to adjust color again the sams says to raise all 3 so I missed something.

[Electronic M]

Originally Posted by timmy

Well this is a Motorola with no service switch I’ll have to adjust color again the sams says to raise all 3 so I missed something.

If you got no switch just pull one of the vert yoke wires or the vertical tube...Where there's a will there's a way. Just because Sam's came up with a procedure doesn't necessarily mean it's right or even factory approved.

[timmy]

Well apparently sams was wrong because I referred to a Motorola book I have for the ts907 and it says to set g2 to mid point that’s alot less then all the way up as sams says. Well I hope I didn’t damage the flyback I did check the donut ohms it measured 586 ohms so I guess it’s ok.

[timmy]

I got the color pattern to help assist, it was tough to tune it in but I did but regular tv has color bars just waiting to drop on to a picture . this IF business really sucks trial and error but the pattern started out with no color at all. Using a dvd with an rf modulator to the antenna terminals this is what I was able to get after adjusting but how much different is the antenna signal compared to the dvd signal.

[dtvmcdonald]

Well well well! That proves that each and every part of the set works.

Interestingly, the color bars from bottom up (orange up) are + and - I then
- and + Q.

Where does that test pattern come from? What DVD?

[timmy]

Originally Posted by dtvmcdonald

Well well well! That proves that each and every part of the set works.

Interestingly, the color bars from bottom up (orange up) are + and - I then
- and + Q.

Where does that test pattern come from? What DVD?

PM5544 find it on line take a picture on the computer then burn the image on a dvd that’s what I did. While it may look good on this set it’s not because red is not exactly red the colors are not there yet. Kind of not understanding while the colors look ok they seem to be in the wrong place and not exactly what the pattern shows maybe because it’s a digital image.

[dtvmcdonald]

I found the original.

The image on your TV set has a seriously wrong "red" or "magenta" bar. The exact nature of the problem ... undersaturated ... is very frequently
that the main video carrier is at an improper spot on the IF response slope.

I strongly suspect that all your set now needs is a full IF and possibly but less likely also RF alignment, and getting the AGC working right. The AGC won't work
right unless the video carrier is at the right spot on the slope.

The CTC-5 at the ETF which I worked on last spring has the exact same
problem.

You seem to be a patient person. Its perfectly possible to align a TV
with nothing but a plain signal generator and an analog voltmeter! Just
use the bias box you already have to override AGC and meter at the
video detector, plain DC. You can in a pinch even use the second harmonic
of the oscillator of a SW radio, you just have to take into account of that
oscillator's (typically 455 kHZ) offset from the dial. I've actually done that
in a pinch!

[timmy]

Originally Posted by dtvmcdonald

I found the original.

The image on your TV set has a seriously wrong "red" or "magenta" bar. The exact nature of the problem ... undersaturated ... is very frequently
that the main video carrier is at an improper spot on the IF response slope.

I strongly suspect that all your set now needs is a full IF and possibly but less likely also RF alignment, and getting the AGC working right. The AGC won't work
right unless the video carrier is at the right spot on the slope.

The CTC-5 at the ETF which I worked on last spring has the exact same
problem.

You seem to be a patient person. Its perfectly possible to align a TV
with nothing but a plain signal generator and an analog voltmeter! Just
use the bias box you already have to override AGC and meter at the
video detector, plain DC. You can in a pinch even use the second harmonic
of the oscillator of a SW radio, you just have to take into account of that
oscillator's (typically 455 kHZ) offset from the dial. I've actually done that
in a pinch!

What is exactly the main video carrier are you referring to the rf modulator with DVD player or in the IF strip. what would I do at the detector measure voltage from what to what ? All I have is a tuner subber.

[dtvmcdonald]

By video carrier I mean the main carrier of the RF signal ... 1.25 MHz up from the
bottom frequency of the channel (at RF .... down from the top at IF).

But if you don't already have something suitable as generator .... There's got to be
somebody near you who can loan you one and show you even a bit how to use it.
I'd do that if I were not 1000 miles away.

Doug

[timmy]

But if I was to get that pattern perfect color wise does that mean color in video would be good also.

[Yamamaya42]

Originally Posted by dtvmcdonald

By video carrier I mean the main carrier of the RF signal ... 1.25 MHz up from the
bottom frequency of the channel (at RF .... down from the top at IF).

But if you don't already have something suitable as generator .... There's got to be
somebody near you who can loan you one and show you even a bit how to use it.
I'd do that if I were not 1000 miles away.

Doug

yeah, they are not cheap

i got this a year or so back to align my BW Arvin TV.
https://tinyurl.com/24atccvt

[timmy]

Originally Posted by Yamamaya42

yeah, they are not cheap

i got this a year or so back to align my BW Arvin TV.
https://tinyurl.com/24atccvt

So what exactly does this unit do ?

[Yamamaya42]

It's a multifunction RF signal generator that goes up to 60 mhz, does sine wave, square-wave, Triangle half, and many others, sine wave in the 40 mhz range is what is needed to do TV alignments with exact control. Which what this has be cause you can set the freq and amplitude.