a real challange?

[Yamamaya42]

OK...

replacing the bad 150 ohm resistors helped, but still have a snowy pic.
https://www.youtube.com/watch?v=6jkf0HXpEEE
the 99v is now 112v. which i guess is OK the MAIN 130v is at 115v, i really do not expect ALL voltage to be exactly as shown on the schematics.

given that 3 out of 4 150 ohm resistors were over 250+, its a good chance that there are many more that are VERY bad :/

[Kevin Kuehn]

Originally Posted by Yamamaya42

adjusting the 1st IF coil helped a bit, but I still have a lot of RF noise, the B+ getting to the tuner is very low, 99v where it should be 130v i need to replace resistors in the IF bias chain, cause they put the tuner at the END of that chain :/

Did you adjust the 1st IF per the alignment instructions using your new rf generator, or was that a best visual tweak attempt? You are still using the test CRT in that last video? It almost looks like outside interference.

[Yamamaya42]

Originally Posted by Kevin Kuehn

Did you adjust the 1st IF per the alignment instructions using your new rf generator, or was that a best visual tweak attempt? You are still using the test CRT in that last video? It almost looks like outside interference.

i tried but got no reaction via the trap A4 adjustment as per instructions , so i did a4 visual

i am still using the test CRT

I am starting to doubt this rf generator is viable, HOW exact does it have to be for this?

it could be outside interference, but i have the rf mod hooked up directly to the set, how sensitive can it be?

[Kevin Kuehn]

Originally Posted by Yamamaya42

i tried but got no reaction via the trap A4 adjustment as per instructions , so i did a4 visual

i am still using the test CRT

I am starting to doubt this rf generator is viable, HOW exact does it have to be for this?

it could be outside interference, but i have the rf mod hooked up directly to the set, how sensitive can it be?

Ideally it need's to be quite exact, but if it weren't too far off frequency I would expect you'd still see a peak or dip per alignment directions, it would just be off a little from where it's suppose to be. What influence does the contrast control have on the picture, and were you able to get that -3v bias before you adjusted A4,A6?

[Yamamaya42]

Originally Posted by Kevin Kuehn

Ideally it need's to be quite exact, but if it weren't too far off frequency I would expect you'd still see a peak or dip per alignment directions, it would just be off a little from where it's suppose to be. What influence does the contrast control have on the picture, and were you able to get that -3v bias before you adjusted A4,A6?

the "contrast control" as they call it has a profound effect on the picture, it can effect it to the point that nothing is seen or heard on the screen, I hardly can call it " contrast control" persey as it seems to adjust RF gain in place of modern AFC.
and yes, I was able to see the -3 at the point that said in alignment, but adjusting A4 had no affect on it or picture. a6 did have affect on picture.

this was with the signal sent into the ANT , as instructed.

I am going to send this generator back for favor of a vintage one.
i found this very disturbing
https://www.youtube.com/watch?v=iuE7OliznSo

[Kevin Kuehn]

Yes that so called contrast control is only adjusting the gain on the 3 IF stages. I don't own a RCA 630 type set, so I'm not the very well versed on it's operation. It would be nice if someone familiar with those TV's would chime in on how that control normally affects the picture.

I'm with you on sending that generator back and going with something vintage. I will however say that you won't get nice clean sine waves and flat frequency response from most service grade generators, but I'll bet many will do better than that unit.

[Yamamaya42]

seeing this out of it was the last straw...
https://imgur.com/jsAMOP9
that and not having it stay on freq.


i have one of these coming.. said to be in good working order..
https://www.radiolaguy.com/Showcase/...t/EICO_324.htm

[old_coot88]

Whatever genny you use, remember to keep the signal level attenuated to the minimum that's consistent with a good noise-free trace.

[Yamamaya42]

Originally Posted by old_coot88

Whatever genny you use, remember to keep the signal level attenuated to the minimum that's consistent with a good noise-free trace.

i can't find anyplace in the alignment setup what the signal level should be, the EICO can be set from 0 - 10 volts out, so I guess it's to be set at the lowest that has an effect?

[Kevin Kuehn]

Originally Posted by Yamamaya42

i can't find anyplace in the alignment setup what the signal level should be, the EICO can be set from 0 - 10 volts out, so I guess it's to be set at the lowest that has an effect?

Yes, unless stated otherwise lowest signal needed to get the response. And if there's AGC in the set you generally disable that by applying a fixed voltage. I'm talking about TV's, AM radio on the other hand you can usually get away with monitoring the AVC line for strongest signal while adjusting the IF's.

That sine wave distortion you show in your last post, believe it or not that kind of thing really won't bother for alignment. We need to remember that the RF is only the carrier for the modulating sound and video information, so the important thing is the response of the video IF amplifiers, and for that you need the generators frequency calibration to be accurate.

[jr_tech]

Originally Posted by Kevin Kuehn

That sine wave distortion you show in your last post, believe it or not that kind of thing really won't bother for alignment. We need to remember that the RF is only the carrier for the modulating sound and video information, so the important thing is the response of the video IF amplifiers, and for that you need the generators frequency calibration to be accurate.

Indeed true... I have seen far worse distortion in the output of my Heathkit SG-8, which is similar in design to that Eico. For 21 mhz if, I use a small digital shortwave radio to measure and set the frequency accurately.

jr

[Kevin Kuehn]

Originally Posted by jr_tech

I use a small digital shortwave radio to measure and set the frequency accurately.
jr

That's a great idea, and one I keep forgetting about.

[Yamamaya42]

i got one of these, https://www.youtube.com/watch?v=1_neC5Z_wEg
which seems to do a good job.

[Electronic M]

AM alignment generators like that EICO ( which will work for marker generator in sweep/marker TV alignment with an additional RF sweep generator) tend to have very non-sinusoidal waveforms...which helps with radio alignment...the distortion makes the modulation detectable to FM radios and eliminates the need for a dedicated generator for FM...those waveforms can boggle some frequency counters into giving false readings....I have an older HP pure sine wave generator that lacks modulation so if I need to know precise frequency from my modulated tube Heathkit alignment generator I connect it to a scope, count divisions a cycle takes, hook the HP to the scope and dial it to the same number of divisions and then hook the HP to my frequency counter...the reverse can be used to set the Heathkit...
I'm a fan of finding (needlessly) complex ways of circumventing limitations of my test equipment.

[Yamamaya42]

Originally Posted by Electronic M

AM alignment generators like that EICO ( which will work for marker generator in sweep/marker TV alignment with an additional RF sweep generator) tend to have very non-sinusoidal waveforms...which helps with radio alignment...the distortion makes the modulation detectable to FM radios and eliminates the need for a dedicated generator for FM...those waveforms can boggle some frequency counters into giving false readings....I have an older HP pure sine wave generator that lacks modulation so if I need to know precise frequency from my modulated tube Heathkit alignment generator I connect it to a scope, count divisions a cycle takes, hook the HP to the scope and dial it to the same number of divisions and then hook the HP to my frequency counter...the reverse can be used to set the Heathkit...
I'm a fan of finding (needlessly) complex ways of circumventing limitations of my test equipment.

I'm expecting the EICO to be quite more stable than the POS I'm sending back, it was bouncing all over the place, (+- 100-250 khz) , was just too unstable.
Many others saw the same problem.

I intend to hook up my little counter like this guy did here.
https://www.youtube.com/watch?v=wO4oErefk3s

This should give me a tool good enough to align the thing.