old zenith ringing

[maxhifi]

Now that my old Zenith portable is displaying colours accurately, another issue has made itself visible.

I am not sure if ringing is the correct term, but will attempt to describe. When text is on a strongly contrasting background, a shadow of it can sometimes be seen to the right, but never the left.

This is a different phenomena than when brightness is excessive, and the entire text goes out of focus. It is most especially noticible with black text on a white background. during video which doesn't involve titles or graphics, it is not noticible at all, and if the background is lower contrast, say green on grey, not noticible either. Any ideas what causes this effect?

[andy]

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[maxhifi]

I suspected it was an IF/RF related problem. May also be because the TV is fed though a long run of coax with a couple splitters in between. Tonight i'll try a direct connection, and also try to inject composite video directly after the video detector. The 'ghost' issue is limited to high contrast text though, and really has a minor effect on the overall tv watching experience.

[tvcollector]

I had a similar with a 1979 Silvana console set i owned in the 90s.. All CRT tvs have ghosting which alot of people don't have the ability to hear the high pitch ringing. Mine would do it much louder than normal, upon warm up, and the problem was the suckion cup was loose.. I also had a old Panasonic Quasar same model set as pictured

back in 1991 a customer my mother was working for gave to her. One night watching it, it all of a sudden sounded like a bottle rocket fire cracker was lit and went off along with the high pitch ringing and of course the set went blank, still the audio was on, and the gases really smelled which at the time i thought it smelled just like gun powder.. To this day i wonder what caused that to happen with eruption, boy did i jump through the roof when hearing that..

[maxhifi]

My bad - Still new to this TV repair thing.

I think this website needs a glossary section
I was trying to find the correct word to describe what I was noticing by searching old posts... looks like I got this one wrong.

I thought ghosting applies to the whole picture, so was trying to find a more specific description. When I lived in a high rise apartment, there was such severe ghosting caused by multipath reception from reflections off other buildings, that over the air TV was completely useless. This is nothing like that, it only affects text - and then only sometimes. A good example is on the news, when they show the weather forecast.

I can hear the 15KHz from my Zenith, but it's more or less the same as all TVs.

[old_coot88]

Try subbing the 3rd IF tube. It can cause ringing.
Bill(oc)

[ctc17]

Originally Posted by aaren253

Behoov, heathenish, too vivid light of day, elaborate embroidery and fantastic flourishes of gold-thread, appeared the letter A.
To perceive how the beauty shone out, disentangling its mesh of good and evil, at a loss in the pathway of human existence.

I can tell you do your demographic research trying to hawk Chinese trash to this group.

What is the chassis number of this Zenith again?

[maxhifi]

Hybrid set. 14DC16
Tube tuner
solid state IF
Tube video