Re: Sony KV-A2942U very soft focus in middle of screen
 

Hi Marcel

Thank you for the update.

I wonder, given the technical improvements made for both colour cameras and televisions, following the NTSC standard in 1953 being approved for 525 lines, if the subject of colour TV developments wouldn't make an excellent article for the BVWS magazine.

When one thinks that it was only 15 years earlier that the BBC started the first high definition standard regular public broadcast on 405 lines with the technology available at the time..

I'm not technically competent to contribute having really only the articles in Television and the earlier Practical Television, plus others to call upon.

However, there are many contributors to this site who would be ideal?


Chris

Re: Sony KV-A2942U very soft focus in middle of screen
 

The frame of the wire mask is particularly heavy.

I've seen the rainbow and misconvergence errors from sets that were dropped. Never knew about focus problems.

Re: Sony KV-A2942U very soft focus in middle of screen
 

In my (limited) experience, in higher res computer monitors, the wire mask was the limiting factor.

Re: Sony KV-A2942U very soft focus in middle of screen
 

Early shadow mask tubes also had cages around them. Later integrated into the tube, probably the same with Trinitron. I think most of the metal weight is the tension frame for the wire mask (aperture grille).

Re: Sony KV-A2942U very soft focus in middle of screen
 

Just to slightly derail my own topic, I've noticed some pretty heavy blooming on this TV. I wouldn't expect this on a Trinitron of this era, at least to this extent.

https://youtu.be/TWft0C2t-E4

It's effect isn't as apparent in the video as it is in real life, this is far less than when a white screen is flickering (basically a blurry chaotic mess).

Is this something I should be blaming the flyback for? Are AE2 chassis really this bad? My AE1 set doesn't bloom like this.