CurtPalme.com Home Theater Forum

km987654 · Posted: Mon May 05, 2008 6:48 am Post subject: EM & ES Focusing

Can EM focusing technology be applied to ES focus tubes?? or is there a difference in tube technology?

Thanks

KM

Zebu Fellenz · Joined: 21 Dec 2006 Posts: 2567

The tubes are different

**kal** · Posted: Mon May 05, 2008 2:33 pm Post subject:

For a complete explanation see: http://www.curtpalme.com/CRTPrimer_12.shtm

Kal

km987654 · Posted: Mon May 05, 2008 9:40 pm Post subject:

Thanks Kal

I have read that but it doesn't answer my question. Could you apply EM focus technology to a tube from and ES focus projector. The article doesn't address different tube technology rather different focus technology.

rpruen · Posted: Tue May 06, 2008 7:11 am Post subject:

In theory I guess it would be possible, depending on the internal construction of the tube. I seem to recall that Bang And Olafson (sp?) TVs with large screens had ES focus, but also had a coil, or set of coils that allowed the focus to also be tweaked electronicaly. I can't remember if it was focus, or astig (though that is the same sort of thing)

This was one of those mad things with about 50 pots to tweak, to adjust the picture. Though that wasn't my thing at the time, I used to work on power supplies, and some of the electronics.

This was a RPTV so basicaly a projector. However it's many years since I worked on that set. I seem to recall it was in a cabinet, with built in laser disc player. At the time it had everyone in the repair shop stunned by the hi-res quality, this was before HDTV as we know it now.

Richard

Ile · Posted: Tue May 06, 2008 8:11 am Post subject:

Gun assembly is different inside tube neck, because ES tubes form focus internally and EM tubes need focus yoke for that.
Projection ES tubes have shorter neck, so neck don't have room for focus yoke.