CurtPalme.com Home Theater Forum

[JustGreg]

The title says it all. Like many here I just spent many precious hours taking down my 8500, replacing the tubes, some boards, installing my own brand of harmonic sound deadening, a few board level components, Joust Mods and 145's, a nice overall black paintjob, electric winch, etc etc.

I followed BB's setup to the letter and still ended up with banding. As I work long hours on the ass end of the day I don't have alot of time so any time I have to dedicate is grudgingly eeked out. I REALLY would prefer not to do a full init but past experience has shown that to be the 'best' remedy. Has anybody successfully fixed banding without going to that extreme?

I'm especially miffed because I abandoned my 'ghetto' ways of setting up the pj and commited to a respected method (of setup). I used very very little bow, skew and keystone and random adjustments only. In the past I winged everything and had no banding but poor corner focus and stig. Now it's crisp (except for the bottom right corner which so far has resisted all efforts to tighten it up...but I'm a stubborn old cuss! ) and dread all the leaning over backward underneath the beast to do it all again.

O'tay...nuff said I guess. Bring on the answers (to a question which I suppose I already know the answer to).

[Tim in Phoenix]

Hello


First null all convergence in two steps; for Green hit CONV, 5, 0901, 1 and 0. For Red/Blue hit CONV, 1, 0. The remaining steps are explained here: http://www.etechvideo.com/techtip10.htm

Let us know how it works out.
.

[Nashou66]

Hi Greg. You can Just go into convergence and hit 0 and it will null all convergence, do the same for green service. What you need to do every so often while doing convergence is stop after say a 5 or 6 convergence points and put up the full field to see if banding reared its ugly head. It usually comes when moving the grids up or down.

Also some times using C or S linearity a click up or down will un-squeeze the grid that the convergence caused. that is what causes Banding from my understanding is the compression of the scan lines in bands from either convergence, linearity or bow.


Oh And use interpolated on the Service green and then on the other colors, after your done and it needs tweaking, use it one more time, then you can do the random access.


Now for the one corner you cant get focused, I found in some set ups you do in fact need to remove the factory caps for the Scheimflug screws. This will help focus the one corner you can never get.

Athanasios

[JustGreg]

Thanks for the reply guys...that's exactly what I was looking for! I did use quite a bit of S and C linearity and perhaps too much bow as the 'new' tubes I installed seemed to have badly bowed horizontal lines. I'm sure the tubes have nothing to do with the upside down smile looking lines as they only display what's sent to them...but I didn't do anything to the board(s) that would cause it.

I'll give it all a go this weekend (on my ONE day off...screw raking leaves) and let you know how it went.

I'll also try to post some pix soon of the ventilation for the hush box too (in progress). I have an I beam a few mere inches away from the front of the pj that I boxed in and got to thinking why not make it ductwork? So while boxing it in with drywall I built in stops inside the air space just to the right of the pj (looking at it from the back), and outside the theater I did the same to the I beam and added a stop about a foot from the wall. The other side of the I beam 'duct' is going to deliver heat and AC.

In that one foot area I'll be installing a 3" x 8" 120v squirrel cage blower from a copy machine in a custom enclosure to pull air through HEPA filters built into the hush box. HEPA (I'm thinking about charcoal but need to do more research. I don't want to restrict the airflow to the pj at all if it can be helped) because I have smoker friends and I built this room to entertain in...so a little smoke doesn't bother me and makes them happy. Hell, I weld and grind all day. My lungs take a worse beating at work compared to the infrequent smoker visits I get. And I don't have to pause the movie every 20 minutes so they can leave to get a fix. I enjoy a good cigar now and then myself as a matter of fact.

To continue, (the plan is) I'm going to use a MicroLogix PLC controller and a thermocouple to control the blower on/off and speed. The "plan" is to 'Y' the output from the blower to the outside in summer, and into the furnace cold air return in the winter. The routing will also be controlled by the MicroLogix and another thermocouple.
If I smell smoke anywhere upstairs...then smoking is out....period. The screen is soon to be Wilsonart so that'll be washable but I won't tolerate a smoky smelling house.

Fun fun fun! Now I need to learn how to make home brew...but the bar is just a sketch right now so it'll have to wait.

Thanks again guys!

[AnalogRocks]

Greg you need to take some "sick" time off work to play with your toys

[AnalogRocks]

Greg you need to take some "sick" time off work to play with your toys

[Nashou66]

Greg, you said new tubes. were these bare? You might have lined up the convergence yolks wrong or the deflection coils. Just asking it might not be that at all but worth looking at.

Athanasios

[draganm]

I was thinking about offering a Banding fix for the Marquee. It's a Bear though and requires a PLC programmer, additional chips, etc. I'm wondering if there's a market for this, lets say $500. per CLM including a re-cap?

[JustGreg]

Athanasios....they weren't bare but...you've definately given me something more to look into. As much as I dread tearing it apart again I will if that's the problem or else...why bother right? I would rather do that than depend on electronics to correct a physical misalignment.

Draganm...If you could make banding more difficult to achieve as opposed to the current fine line of adjustment to prevent it; as well as coupling a CLM upgrade....who knows. $500 sounds like it would be in the ballpark and might be justifiable to the 'Set it and Forget It' type CRT-er. Speaking for myself however I would rather use that money for an upgraded AVR with HDMI switching/processing. (4+ HDMI inputs please). That said, I DO need to start putting some money aside to have you hunch over my boards with a soldering iron for a day or two and bring them into the 21st century. We'll see what spring brings.

AR...I would LOVE to take some sick days but I work at Satan's Waiting Room....or put another way; a company where good mechanics go to die if you stay long enough. NOT a nice place. In addition to myself and crew being human haki-saks (sp) for a company helmed by insensitive money grubbing dickheads, we work on machines that make the burger patties for famous fast food restaurants. Inside these machines (away from product contact) is not a place for the squeemish. Old wet, cottage cheesey looking meat, gack, slime, mold, bacteria, etc. If people that ate Wendy's burgers (the dept I'm responsible for) only knew what I know. Put simply, I haven't eaten a Wendy's burger since shortly after starting work for this company.
I DO qualify for a weeks vacation Dec. 8th tho! So will be putting some time into my house; that's been neglected for the last year.
Lesson? KIDS! STAY IN SCHOOL AND GO TO COLLEGE!!!

[draganm]

[Nashou66]

Dragan , what chips do you mean that will stop banding? With my old marquees banding was easy to get, on Ultras I think they did much better either because of the extra geometry controls or the ultras software, I can still get my Longbows to band but it takes much more work that to not have it band

Athanasios

[draganm]

[Nashou66]

I don't understand what you plan to do? Unless there is something in the newest Marquee's that prevent banding and you plan to flash a new e-prom for U44 with the same data from the new Marquee's.

Athanasios