CurtPalme.com Home Theater Forum

[Nashou66]

Hi Guys, I thought this should be added to the thread since it might make a difference for some not all Astig amp boards
(SAB). I was having this nasty noise issue on my longbows where there were bands of vertical squiggly lines running across the screen. I ended up scoping the boards on the rear heat sink and found it was the SAB. I guess Scot knew this board was a problem. here is a repost of my findings and Scotts comments on the baord.

Here is a pic of the squiggly lines

[mp20748]

[Nashou66]

Thanks for the scope pics Mike!

When i finally get time to add the parts you did i'll add it to this thread , i bet the combination of the beads and the board changes will be awesome . Can you PM the inductor values or post them here? I keep meaning to order a inductor kit with a bunch of values but always forget.

Athanasios

[mp20748]

[Nashou66]

I have 33uf tants. And some 220uf inductors. I know the tants should be ok just not to sure of the inductors.

Athanasios

[1031]

I´m joining to this project also (Maybe after Xmas) I was able to get parts so that a can upgrade my test bench to M8500
(Big thanks to member Menec!)
I still have bunch of "three leg" EMI filters for different frequencies, so i think i´ll test those also and see if those are usefull for this project.

[draganm]

excellent paper on new, modern, low ESR low ESL capacitors and how they are being used in de-coupling. They talk about the old school approach of looping EL's, MLCC's, and Tants run in parallel within each loop and how this tends to produce oscillations. I think the MArquee VNB uses this philosohpy as you see a EL cans, followed by small 1uf tants and finally MLCC's.
It looks like the new approach is to use fewer of the new design style caps covering a much broader power filtering frequency and improved performance. By doing this you eliminate the oscillations between loops and also reduce board foot-print which is always good for noise reduction. They're even changing the packaging of the SMT tant's to reduce current loops, really cool stuff

http://www.kemet.com/kemet/web/homepage/kfbk3.nsf/vaFeedbackFAQ/E631B0BDEAB819C18525741700738042/$file/2008%20CARTS%20-%20Decoupling%20Solutions.pdf

Wouldn't it be cool to sit down with the MArquee VIM or VNB's and apply some of these newer techniques. I bet you could actually shrink the entiree size of the board and have a cleaner signal to boot.
I realize they are talking about crazy high bandwidths for PC CPU's but I would expect some of this would apply to a CRT video chain? Especially the 2035-03P VIM
Let the raging argument begin

[HK-Steve]

Just when I thought I could have a quiet night without thinking about the Marquee,

Now this,


Nice fine draganm , lots of good info.



Oh No, The Wife just saw what I printed to read, looks like I will be on the couch again reading.
Nothing new there.



Have a Great New Year to all


Cheers
Steve

[Nashou66]

Steve want to read some other radical stuff? Ivor Catt, he has some interesting ideas on SFR of caps.

http://www.ivorcatt.com/2603.htm

he might be a little bit out there but his digital stuff makes sense for decoupling.

he has lots of other interesting stuff, a bit of a whiner but still entertaining.

Athanasios

[David_Web]

I finally have my projector apart to change tubes.

I though I would add some clamp on ferrites where applicable.
So where should I put them?
And where should I not put them?

I guess between LVPS and HVPS could not hurt.
The right lines for VIM and CLM, VDM and the other boards. And of course P14. (Ill settle for some simple noise suppression right now but will mod more later)
But what have priority and where?


I figured that to limit the EMI from noisy lines it should not matter where it is put as the only thing we care about it current.
Volt should not matter for power rails as it goes hand in hand with current (AC).

How about the long black cables that goes from HVPS to VNB? OK to put a ferrite on them?

And a last question. Is 6.30V ok for P14? At least till I fix it later. I would guess no more than 100-200h or so.

[dvh99]

i read somewhere the astig cables are the worst and that you should look at ferriteclamps specced 10mhz or less for those cables.
if you want to be sure ask nashou he`s the mod expert.
if you havent got his bellows yet order them cause they will leak someday if they dont already.

[David_Web]

I don't have astig amp installed yet. Ill see if I need it first. I have enough for it if I install it later.

I ended up doing +-85V lines and the three lines going to each VNB. Also one big between LVPS and HVPS. And one around the smaller connector to the mainboard.
And one on each leg of P14.
Not sure what spec they are but any is better than none, at least when it comes to PSU lines.

Marquee 7500 (8110) so no bellows =)

I hope to get it together today so I have two days to tweak it until movie night on Saturday.

[Sparky015]

If you haven't done so, check out Mike Parker's thread section about adding the ground wire. You may not have the issue though, if you don't have ASTIG, however it wouldn't hurt for the convergence board.

[David_Web]

I used to have snow in my picture but now there is no hint of it, so it must have done something right.

I also found out all three magnetic rings are active. At least on green where I could detect the middle ring (faint but present). Not sure about R and B as I could not see any change, although it might be easier when I have done mechanical setup properly.

I hate leveling deflection yokes, have to turn it off for a while between adjustment. Me and HV does not play nice together so I might as well be careful.

Could you post a link to that ground wire?

[Sparky015]

https://www.curtpalme.com/forum_archived/viewtopic.php@t=19972.html

[David_Web]

Thanks. Might just plug in a pin and put it to ground. No need to solder until I need astig.

[dvh99]

can you just add an astig amp???
there is a stig waveform generator on the clm on models with astig.
need to change the focus coils too.

[David_Web]

I do have coils with astig windings (installed them with the new tubes). I also have an astig amp that would be easy to clamp on even with the PJ in position.
Might add it later but now I need it running for tomorrow.

Proper source setup next =)
After I put on the casing that is, no need to fry it with bad cooling too much. Not that it gets that hot.

[DGP]

[Nashou66]

Hi Diego, I used the larger grey TDK Z-CAT ferrite clamps on the astig board right near the connector. I tried some other types but the Z-CAT ones worked the best. Try different types to see what works.

Athanasios