Videokarma.org TV - Video - Vintage Television & Radio Forums

Videokarma.org TV - Video - Vintage Television & Radio Forums (http://www.videokarma.org/index.php)
-   Rectangular Screen Tube Televisions (http://www.videokarma.org/forumdisplay.php?f=45)
-   -   Motorola 19k14wa Possible Arcing? (http://www.videokarma.org/showthread.php?t=269293)

mr_rye89 07-13-2017 11:13 PM

Motorola 19k14wa Possible Arcing?
 
Hey guys, I powered her up tonight and noticed a funny hissing noise as well as some horizontal waviness which went away after a while, and the set seemed fine. I turned it off and waited a while, then with the back and HV cage off I watched it power up in the dark and didn't see anything funny. it did hiss a bit but the picture looked okay upon warmup. All tubes test okay (at least around the video/horiz/vert section) but I haven't tested the HV rectifier.

Only other thing I noticed was a blue glow in the damper diode (12AF3), but that shouldn't be a concern right?

http://i263.photobucket.com/albums/i...psegk9dzgp.jpg

WISCOJIM 07-14-2017 12:33 AM

1 Attachment(s)
The Photobucket image...


http://www.videokarma.org/attachment...1&d=1500010320

VintagePC 07-14-2017 07:01 AM

IIRC that blue glow is fluorescence of the glass, not uncommon in power tubes and nothing to worry about

zeno 07-14-2017 07:49 AM

Blue glow in power tubes is common.
To find arc do it on a very humid day in the dark.
Also check the HV rect socket for corrosion, a white or
greenish color usually or sometimes rust.

73 Zeno:smoke:
LFOD !

Electronic M 07-14-2017 10:27 AM

Quote:

Originally Posted by WISCOJIM (Post 3186727)
The Photobucket image...

How are you rescuing photobucket images/bypassing photobuckets' new policy of requiring money for external hosting to work? I can't even view pictures bigger than the gallery thumbnails in bucket accounts.

DavGoodlin 07-14-2017 10:52 AM

I had pretty intense arcing out from the CRT connector on a similar Motorola when I first started messing with TV over 40 years ago. Optimal time of year for that nonsense! I had to clean the CRT and then the connector suction cup rubber with silicone to get rid of all the tracking. The HV rectifier was a 3A3, like what a color TV used, so I know the HV was higher than normal BW sets.

What is the chassis number? Mine was CDTS581YA totally all-gray metal 19" cabinet, like my avatar.

WISCOJIM 07-14-2017 02:03 PM

Quote:

Originally Posted by Electronic M (Post 3186737)
How are you rescuing photobucket images/bypassing photobuckets' new policy of requiring money for external hosting to work? I can't even view pictures bigger than the gallery thumbnails in bucket accounts.

I didn't bypass the PB requirement, I just accessed the image with their link, saved the image, and then uploaded it directly to VK.

I right click on the PB update image in the post and either hit open image in new tab or open link in new tab. (I am using Google Chrome.) That gets me to the PB page, which again shows the PB update image. Then I right click on that PB update image and open the image in a new tab, which then displays the real image. I then save the image to my computer, and upload it to VK through the Manage Attachments feature, and then use the VK assigned link for the image within the IMG and /IMG tags to display it in the thread.

The old images are not difficult to access this way, just very time consuming. I fear that anyone who closes their PB account will be eliminating this access path, so I advise everyone to leave their PB accounts idle rather than closing them.

I think everyone involved in this fiasco get a class action suit going against PB to force them to grandfather in all old images to be usable as hot-linked 3rd party hosting, as that is what the policy was when they were placed on PB in the first place. The recent changes are a violation of trust against all who used PB.

.

mr_rye89 07-14-2017 09:44 PM

1 Attachment(s)
I figured the blue glow was nothing, the power tubes in my home stereo have a blue glow, but I'm kinda a noob to TVs......

I fired her up tonight and found some arcing in the HV rectifier socket, though it looked like it was happening inside the tube. Time to pull it out for a good clean!

Quote:

Originally Posted by DavGoodlin (Post 3186740)
What is the chassis number? Mine was CDTS581YA totally all-gray metal 19" cabinet, like my avatar.

I couldn't figure out the chassis number, but its in a floor standing wood Danish modern style console. I attached the picture this time to avoid the PB blues

http://www.videokarma.org/attachment...2&d=1500086543

mr_rye89 09-17-2017 10:25 AM

So this TV has been playing well, I replaced the HV lead, cleaned the cage, replaced the tubes in the tuner. I also cleaned the "noise gate" pot, it was scratchy and made the picture go wavy/buzzy intermittently.

only quirk I have now is some buzz in the audio which can sometimes be minimized with adjustment of the fine tuning. Perhaps I have a dirty tuner? or could it be alignment related?

maxhifi 09-17-2017 10:34 AM

Quote:

Originally Posted by mr_rye89 (Post 3189608)
So this TV has been playing well, I replaced the HV lead, cleaned the cage, replaced the tubes in the tuner. I also cleaned the "noise gate" pot, it was scratchy and made the picture go wavy/buzzy intermittently.

only quirk I have now is some buzz in the audio which can sometimes be minimized with adjustment of the fine tuning. Perhaps I have a dirty tuner? or could it be alignment related?

Sometimes this is just a fact of life with old TVs, especially when digitally generated text is shown. Alignment can definitely help, especially if the best picture and sound appear at different parts in the fine tuning range.

Really nice TV!

Electronic M 09-17-2017 08:06 PM

If your using a cheap consumer grade modulator it can be the modulators fault. Some units use a single carrier osc. that gets AM and FM modulated...If the AM video modulation exceeds %100 it will also affect the FM sound...As noise that repeats at 60Hz and varies with video content.

mr_rye89 09-19-2017 08:14 PM

Quote:

Originally Posted by maxhifi (Post 3189610)
Sometimes this is just a fact of life with old TVs, especially when digitally generated text is shown. Alignment can definitely help, especially if the best picture and sound appear at different parts in the fine tuning range.

Really nice TV!

Thanks! I'll keep that in mind.

Quote:

Originally Posted by Electronic M (Post 3189630)
If your using a cheap consumer grade modulator it can be the modulators fault. Some units use a single carrier osc. that gets AM and FM modulated...If the AM video modulation exceeds %100 it will also affect the FM sound...As noise that repeats at 60Hz and varies with video content.

I'm using a DTV converter box, so that might be the issue. Getting a BT modulator is on my list, as I have some Watchmans that need some use.

zeno 09-20-2017 10:09 AM

Buzz in audio could be AGC, optimizer or noise gate settings,
which ever you have.
You could also touch up the quad coil but there are reasons not to.
Live with it if you can. If not come back for more.
BTW you will need a manual.

73 Zeno:smoke:
LFOD !

mr_rye89 09-11-2018 11:40 PM

Gotta different problem today. washed out picture, barely stable horizontal, hard to lock vertical. Tubes test okay, I re did a bunch of bad looking solder joints with no improvement.

https://farm2.staticflickr.com/1851/...0c44a9ac_c.jpg

maybe it's time to do the power resistors near the horizontal? Goodall film capacitors maybe not so good?

Electronic M 09-12-2018 12:40 AM

Looks like either you've lost gain between the ant terminals and the vid detector*, or your AGC circuit is misadjusted or defective.

*Check signal source, clean tuner, check tuner and IF tubes, wiggle said tubes in case bad socket contacts.

When you develop weak sync in both deflection axes that is a sync separator problem...If the picture has far too little contrast ()along with the synch issue the signal feeding the synch separator (usually picked off just past the video detector) is too weak for the separator to process correctly (even if the separator is functioning correctly which it probably is) due to reasons mentioned in the first sentence.


All times are GMT -5. The time now is 06:03 AM.

Powered by vBulletin® Version 3.8.4
Copyright ©2000 - 2024, Jelsoft Enterprises Ltd.
©Copyright 2012 VideoKarma.org, All rights reserved.