Westinghouse TV no picture : Strip or fix? - Page 10 - Videokarma.org TV - Video

JesusJones · #**136** 09-30-2008, 01:34 AM

Well then maybe my .0547 cap is screwing things up a little.

This could well be the problem to. The BB cap was way off value. And I think was also leaky.

For just testing. Would two .01mfd caps in series work as the .0047 just to see if it helps.

I have two .01's on hand.

electroking · #**137** 09-30-2008, 07:45 AM

Quote:

Originally Posted by JesusJones

Well then maybe my .0547 cap is screwing things up a little.

This could well be the problem to. The BB cap was way off value. And I think was also leaky.

For just testing. Would two .01mfd caps in series work as the .0047 just to see if it helps.

I have two .01's on hand.

Go ahead, that should be much closer than what you currently have.

JesusJones · #**138** 09-30-2008, 01:14 PM

So
I HAVE PICTURE, I HAVE PICTURE!!

Yes I'm not lieing. My .01 .01 series cap did the trick.
But as for the picture being perfect I wouldn't say it is exactly perfect.
Seems like its not vivid enough. Sharp enough. Contrast or something..
I'll play with it some more.

Also the tubes. They get hot right?(normally) Because always after a minute or two I smell the burning hot smell from the heating tubes. And I just wanna be told that's normal. (They're not glowing red)

It finally works

and I couldn't of done it without AK
Thanks guys

electroking · #**139** 09-30-2008, 01:44 PM

Wow! I'm so happy to read that. Hope you caught the bug! If you can get
that camera again, be sure to show us some pictures. Good luck, keep it going!

JesusJones · #**140** 09-30-2008, 03:18 PM

No it's mine and only mine to look at !

hahaha just kidding. I'll have pictures soon. I just wanna spend some time fine tuning it.
I'm very glad it works and would definatley do this again. And probably will.

And I still think that the image on the screen is above and beyond the top of the screen. This is a yoke adjustment if I am correct. But I have never done such a thing, and don't know where to start.(Do I just move it, loosen something, bring out the hammer :P )

also the image is sort of. Weak dare I say. It is showing up but doesn't stand out much. Or is this the quality of such a tv.

Pictures soon!

He he he I'm so happy

JesusJones · #**141** 09-30-2008, 06:19 PM

I'm having 0 success uploading pictures right now. But the picture seems very weak. And other channels wont even show picture. Any ideas as to why this might be?

It's very faint

electroking · #**142** 09-30-2008, 06:31 PM

Quote:

Originally Posted by JesusJones

I'm having 0 success uploading pictures right now. But the picture seems very weak. And other channels wont even show picture. Any ideas as to why this might be?

It's very faint

Do you have at least an old-fashioned rabbit ears antenna hooked
up? Also, the 4BQ7 RF amp on the tuner was weak; did you replace it?
Is the sound reasonably noise free? Typically, if you have adequate
sound, the signal is strong enough and a RF problem can be ruled out
as a cause of weak picture.

wa2ise · #**143** 09-30-2008, 06:44 PM

Quote:

Originally Posted by JesusJones

I'm having 0 success uploading pictures right now.

Maybe your pictures are too big, either file size, or dimensions. Problem is that the picture upload feature at AudioKarma doesn't report back what the problem was, it just doesn't do it. If I recall correctly, there is a note saying the max file size and max dimensions it will take.

JesusJones · #**144** 09-30-2008, 06:46 PM

Yes the sound is pretty good and clear. But it's not perfect.

And yes I have changed the tube.

As for antenna I have two wires hooked up. No rabbit ears. I haven't been able to find a pair.

And what about that yoke?

haha...I'm getting annoyed with the picture thing. I've tried shrinking the picture. I'll just have to do it later.

When reading about amps I always read that capacitors introduce phase shifts. My .0047 is "two" series capacitors. Could this possibly be changing the phase in the feedback loop causing some of this problem?

electroking · #**145** 09-30-2008, 07:05 PM

Unless the yoke was disturbed, it is probably correctly positioned. The trick is to
make sure that the waveforms feeding it are of the correct shape and amplitude.
Better wait until we can see some pictures.

As for your makeshift antenna, you can at least improve things by making it
resonant (on one channel). Find the center frequency of the channel you want
to receive (for instance for channel 7 it would be 177 MHz). Find the wavelength
in meters as 300/(F in MHz), in this case 1.69 meters. Divide by 2 to get the
half wavelength, that is 85 cm. This is the total length of your antenna (in fact
is should be a bit shorter, but if you take two 43 cm long pieces of wire and curve
the ends to fit the terminals, it should be fine).

Just attach the wires to the terminals and spread them horizontally. Be sure not
to get the wire ends in your eyes.

You might also use a VCR or DVD/VCR combo as a source, these usually output
on channel 3 or 4, but you will need a 75-to-300 ohm adapter (still fairly easy to
find as far as I know).

JesusJones · #**146** 09-30-2008, 09:38 PM

I was checking some tubes and I noticed that the 4bq7a is getting rather hot.
About as hot as the vert output or audio output tubes.

This can't be right? can it?

Heres another neat fact. The tv can only tune to one channel.

I should be able to get almost 4 but I only get channel 9. I suspect the tuner. BUt what part?

I also found an adapter. I hooked up my super nintendo. It did not even interfere with the signal. I am very confused

bgadow · #**147** 10-01-2008, 11:48 AM

The tuner may need to be cleaned-a good electronic cleaner should do fine. (de-oxit seems to be a favorite, though I haven't used that brand) You basically give the connections inside the tuner a shower with it (with the set turned off) and then let it dry real well. Right after spraying I'll flip the tuner through the channels and spray a second time, to make sure you get everything covered.

Look for a control marked AGC, if you haven't already. Turned too far one way the picture/sound will go totally washed out; turn too far the other way and it will overload. You need to adjust it just so.

I wouldn't worry about that tube being too hot. It probably has a metal shield around it (or should) and that helps hold in some heat.

JesusJones · #**148** 10-01-2008, 01:44 PM

Well I went over the tuner sorta. I checked with my ohmeter to see that the switched were making contact. It checked in Ok. I also gave it a spray with some electric motor cleaner stuff I have. It didn't help any.

The AGC control you mentioned...I have no idea what it is. But the fine tuning does the same thing. Too far one way no picture. Set it just right and you get picture(For me it's on the one channel only)

I tried flipping through the channels. Turning the fine tunign slightly on each channel. I always end up at the same one.

Some of the channels will show static. And you hear the static. Other channels will give me a dark screen with no sound.
Others a solid grey screen.

Then on the one channel. I can get faint picture. With strong sound.

I have been trying to post my pictures But my internet is screwy or something. It just wont work.

Anyone have any thoughts on my series cap putting the feedback loop out of phase?

Old1625 · #**149** 10-01-2008, 08:38 PM

It seems that you need to check your AGC loop to make sure everything is as it should be there. If the AGC is not working then your picture quality--contrast, brightness, readability, etc--will vary greatly from channel to channel. In such condition your best channels for viewing will be of a critical signal strength--go below that and you may lose contrast--go above that strength and you lose brightness, or the picture may go black, or completely negative. Sync will also go out of whack, and horizontal and vertical hold will suffer.

JesusJones · #**150** 10-01-2008, 09:40 PM

Quote:

Originally Posted by Old1625

It seems that you need to check your AGC loop to make sure everything is as it should be there. If the AGC is not working then your picture quality--contrast, brightness, readability, etc--will vary greatly from channel to channel. In such condition your best channels for viewing will be of a critical signal strength--go below that and you may lose contrast--go above that strength and you lose brightness, or the picture may go black, or completely negative. Sync will also go out of whack, and horizontal and vertical hold will suffer.

This sounds like it could very well be the case. But like I said before I have no Idea what the agc loop is. Could some one tell me where this is? what it is?