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Nashou66
Joined: 12 Jan 2007 Posts: 16171 Location: West Seneca NY
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Link Posted: Wed Oct 07, 2009 12:19 am Post subject: |
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well I just picked up another one tonight 157 shipped. I have the Textronix 2335 dual trace now but wanted one that shows actual digits like the one in jarmos Pics. with my aging eyes its hard to tell what the p_p is sometimes and figure out exact voltages, i was looking for one with a built in MM on top but those are too rich for my blood right now:
this is what i picked up tonight. Click !!
Athanasios
_________________ Don't blame your underwear for your crooked ass~ unknown Greek philosopher
"Republicans believe every day is the Fourth of July, but the Democrats believe every day is April 15." --- President Reagan
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tse
Joined: 03 May 2006 Posts: 1014 Location: Sweatbucket, Fl.
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Link Posted: Wed Oct 07, 2009 12:40 am Post subject: |
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draganm wrote: | I hear you JArmo, getting that noise reduction circuit really dialed in took some time, you can't just slap some beads or inductors in there and have it work perfectly. Your new P14 daughter board works very well, It's just that I'm looking for something really fast and easy that I can do for people without adding a lot of time or effort to the work I already do (which already takes a long time).
I have decided on this, moving the 2 jumper wires to the bottom of the VNB and simply adding a large(ish) ferrite bead to each wire. Yeah I know, it's a simpleton solution but it's neat , quick, and will look like factory work. That always appeals to me, when I'm done and return someone's boards they look like factory boards unless you are really familiar with original ones.
I found these last night at Mouser, they are 5 mm diameter and will fit under the heat sink. they offer 2 different materials , the FB73-422 start to show approx 50ohms impedance at about 1Mhz and filters up to 40 MHz. Impedance can also be increased by stacking a pair of these and if i'm lucky we could start seeing some filtering down as low as the 88Khz noise Mike talks about? At any rate it should be fairly effective for the higher frequency stuff Scott mentions.
http://www.bourns.com/data/global/pdfs/FB_series.pdf
at any rate, it will be a huge leap past the 2 little beads that come stock on the VNB and will be pulling that noise off right as it enters the circuit as opposed to where it terminates at tube pin-outs. I will order these today and hopefully drag a scope home this weekend for some measurements at the pin sockets. |
Yep, those FB43-422-RC jobs should do a pretty good job. Remember, if you add a small cap (0.1uF = 1.6 ohms @ 1MHz) after the bead, it will really help to cut the noise down. Probably a larger cap would help more. Filters are kinda funny to calculate. Try your idea and see the results. Always the best method.
Scott
_________________ "Were we directed from Washington when to sow and when to reap, we would soon want bread."
Thomas Jefferson
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tse
Joined: 03 May 2006 Posts: 1014 Location: Sweatbucket, Fl.
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Link Posted: Wed Oct 07, 2009 12:44 am Post subject: |
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Nashou66 wrote: | well I just picked up another one tonight 157 shipped. I have the Textronix 2335 dual trace now but wanted one that shows actual digits like the one in jarmos Pics. with my aging eyes its hard to tell what the p_p is sometimes and figure out exact voltages, i was looking for one with a built in MM on top but those are too rich for my blood right now:
this is what i picked up tonight. Click !!
Athanasios |
Wow! Nice scope for $157.
Scott
_________________ "Were we directed from Washington when to sow and when to reap, we would soon want bread."
Thomas Jefferson
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stefuel
Joined: 07 Mar 2006 Posts: 3353 Location: Green Harbor MA USA
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Link Posted: Wed Oct 07, 2009 1:00 am Post subject: |
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Nashou66 wrote: | well I just picked up another one tonight 157 shipped. I have the Textronix 2335 dual trace now but wanted one that shows actual digits like the one in jarmos Pics. with my aging eyes its hard to tell what the p_p is sometimes and figure out exact voltages, i was looking for one with a built in MM on top but those are too rich for my blood right now:
this is what i picked up tonight. Click !!
Athanasios |
How much will it cost you to have it calibrated now?
_________________ Chip
A Barco is only a AmPro with training wheels
Card carrying member of the AVS chain gang.
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Nashou66
Joined: 12 Jan 2007 Posts: 16171 Location: West Seneca NY
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Link Posted: Wed Oct 07, 2009 1:06 am Post subject: |
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So far I have been lucky Chip, the 2335 is dead on and I paid the same price for that one. So I can compare the two. Usually the calibration feature on the scope helps determine if its off or not. It is more likely the probes are off, this has no probes, I have some here but I might buy a set of nice new ones, probably more than what i paid for the scope... and by the way Chip, your such a pessimist, go back to your ampro it seems its the only thing that makes you happy beside trashing us marquee folk lol
i was going to get a 2246 but I saw there were two of these from the same place so i bid on one hoping id get it or id have to bid on the second one 25 seconds later.
Athanasios
_________________ Don't blame your underwear for your crooked ass~ unknown Greek philosopher
"Republicans believe every day is the Fourth of July, but the Democrats believe every day is April 15." --- President Reagan
One Smart Dog!!!
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Marquee Modifications and Performance Enhancement
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HK-Steve
Joined: 15 Jul 2006 Posts: 849 Location: Switzerland
TV/Projector: Marquee 9500, Epson 8100
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Link Posted: Wed Oct 07, 2009 9:07 am Post subject: |
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The FB43-422-RC is very similar to the ones I am using, 2 on each cable at each end.
I also add a 1uF cap across D5 and D7.
This knocks down the noise by a big step.
You should also add some filter caps to the HVPS G2 lines. Can't remember the values ATM.
Can get more details for those interested.
Cheers
Steve
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WTS
Joined: 08 Mar 2006 Posts: 1276 Location: Calgary
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Link Posted: Wed Oct 07, 2009 1:26 pm Post subject: |
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Wow, nice scope for $157.00.
_________________ Thanks
Walter
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Nashou66
Joined: 12 Jan 2007 Posts: 16171 Location: West Seneca NY
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Nashou66
Joined: 12 Jan 2007 Posts: 16171 Location: West Seneca NY
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Link Posted: Wed Oct 07, 2009 2:57 pm Post subject: Marquee Mini RCA/Phono Connectors source |
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Scott(TSE) was asking about these parts in another thread so i figured i'd put it here for archive purposes .
these are the mini phono connectors used for the rgb cables. You can use these to make a better cable
to go to the VNB, the right abgle ones are not in stock and they only willput a manufacture order if they are
over 1000 pieces, looks like it only has a hole in the side to accept the signal lead wire into, i just bent the
straight cable connectors end, or you can do as they did and drill a hole in the side(pain in the ass i guess)
http://www.Connect-Tech-Products.com/index1.php?subtype=Mini%20Phono/RCA%20Plugs&id=16
I ordered the straight ones with the longer necks and just bent them.
CTP-175-7A
These are the right angle ones, they have a hole in the side to put the leads into, you need to order 1000
last time i asked.
CTP-175-10A
I paid 25 bucks for 15 of the ones listed above.
I have some here still, I never made a complete set of cables but plan to.
they also have the Sockets, I came across another maker in my recent research but never booked marked it those were SMD mount style though sockets not through hole so not as robust.
Athanasios
_________________ Don't blame your underwear for your crooked ass~ unknown Greek philosopher
"Republicans believe every day is the Fourth of July, but the Democrats believe every day is April 15." --- President Reagan
One Smart Dog!!!
Marquee High Performance Bellows now shipping!!
Marquee Modifications and Performance Enhancement
Marquee C-element and Bellow removal
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draganm
Joined: 08 Mar 2006 Posts: 8990 Location: Colorado
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Link Posted: Wed Oct 07, 2009 3:34 pm Post subject: |
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tse wrote: | Yep, those FB43-422-RC jobs should do a pretty good job. Remember, if you add a small cap (0.1uF = 1.6 ohms @ 1MHz) after the bead, it will really help to cut the noise down. Probably a larger cap would help more. Filters are kinda funny to calculate. Try your idea and see the results. Always the best method.
Scott | Scott the FB43-422-RC shows a range of 40 to 200Mhz. Do you feel that's a better choice than the FB73-422-RC? That ones shows a range of up to 40Mhz. Or maybe stack both if they fit?
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Nashou66
Joined: 12 Jan 2007 Posts: 16171 Location: West Seneca NY
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Link Posted: Wed Oct 07, 2009 3:47 pm Post subject: |
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Yes Drag you got it, you need to cover as many frequencies as possible, so using each one is the way to go, and some times it matters which way you put them in, that is low first or high first, only way to know is to try it. one more hint, i see this on lots of beads like those, wrap the wire once around for a possible 2nd power of 10 attenuation . some info here form this company:
http://www.intermark-usa.com/products/EMC/Ferrite/TRM-WE.shtml
These look really good as they go down to the Khz but they are large. You could put both heater wires into the one bead for the ones i linked I guess. One of the heater lines is the gnd return line correct? I guess it could be done. TSE any thoughts? if they cant fit on the VNB would those work before the connector and just put the wire under the PCB and maybe add a suppression type sheet that that company also makes?
Anthanasios
_________________ Don't blame your underwear for your crooked ass~ unknown Greek philosopher
"Republicans believe every day is the Fourth of July, but the Democrats believe every day is April 15." --- President Reagan
One Smart Dog!!!
Marquee High Performance Bellows now shipping!!
Marquee Modifications and Performance Enhancement
Marquee C-element and Bellow removal
Last edited by Nashou66 on Wed Oct 07, 2009 10:53 pm; edited 1 time in total
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draganm
Joined: 08 Mar 2006 Posts: 8990 Location: Colorado
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Link Posted: Wed Oct 07, 2009 6:48 pm Post subject: |
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wow, those are Purdy. I'll have to see if I can find some of the right size with the epoxy coating down the road. 10mm max OD for my under-card approach though. Thanks for the tip on the loop as well, between you, TSE, and MP I've got some great advice on how to do this.
It's funny I was talking to one of the EE's here and she told me they had to take an entire semester on just noise suppresion, i'm trying to wing it based on a few comments posted on the forum. Talk about a Hail Mary pass
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Nashou66
Joined: 12 Jan 2007 Posts: 16171 Location: West Seneca NY
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Link Posted: Wed Oct 07, 2009 8:04 pm Post subject: |
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draganm wrote: | wow, those are Purdy. I'll have to see if I can find some of the right size with the epoxy coating down the road. 10mm max OD for my under-card approach though. Thanks for the tip on the loop as well, between you, TSE, and MP I've got some great advice on how to do this.
It's funny I was talking to one of the EE's here and she told me they had to take an entire semester on just noise suppresion, i'm trying to wing it based on a few comments posted on the forum. Talk about a Hail Mary pass |
That company does look like it has the things we need but I can't find a distributor. I plan to get some samples, I want to use the Magnefilm sheets either around the HDM case or maybe line the inside of the Plastic Tube housings, I am not sure of the magnetic properties of that type of sheet so once I get them in i will fire up the PJ and put them in close proximity to the tubes , I just have a hunch that the HDM puts out a lot of EMI/RF air born noise along with possible magnetic fields that are just enough to affect focus on the Green and blue(not to worried about the blue though). So that magnefilm along with another soft ferrite type they make could be juts what I need to see a difference in green focus.
here is a neat pic of the Magnefilm's magnetic shielding abilities
And this is another sheet shied I think could be used in certain areas
http://www.intermark-usa.com/products/EMC/MGAbsorptionSheetMG-02A.shtml
Now I know some here think this could be voodoo, but as TSE has said to me and posted in this forum, you never know till you try.
And HK-Steve went crazy with shielding and he swears by it. I think he might be intrested in this product :
But it only comes in 25M rolls way to much.
http://www.intermark-usa.com/products/EMC/Cable/SCB-ME.shtml
Ok enough now , who knows if all this will work but its fun to research and read about.
Athanasios
_________________ Don't blame your underwear for your crooked ass~ unknown Greek philosopher
"Republicans believe every day is the Fourth of July, but the Democrats believe every day is April 15." --- President Reagan
One Smart Dog!!!
Marquee High Performance Bellows now shipping!!
Marquee Modifications and Performance Enhancement
Marquee C-element and Bellow removal
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draganm
Joined: 08 Mar 2006 Posts: 8990 Location: Colorado
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Link Posted: Thu Oct 08, 2009 2:46 am Post subject: |
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I just had a conversation with our local EE today about this. Also, scott talked about it earlier, a lot of the noise in the MArquee is low frequency, like 1Mhz or less usually. In the case of the HDM it's probably more like hundreds of Khz. That cable shielding is designed for data transmission,
Quote: | shielding Effectiveness:
* 85 dB @ 30MHz and 88 dB @ 100MHz. |
For the HMD we need to mill out a solid Aluminum sleeve from billet. 1/4" thick walls oughta do it.
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HK-Steve
Joined: 15 Jul 2006 Posts: 849 Location: Switzerland
TV/Projector: Marquee 9500, Epson 8100
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Link Posted: Thu Oct 08, 2009 6:36 am Post subject: |
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draganm
For the HMD we need to mill out a solid Aluminum sleeve from billet. 1/4" thick walls oughta do it.
Now that would be cool, but the Marquee is heavy enough
I have some EMI tape in the mail, will let you know how it goes for shielding.
Cheers
Steve
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Tom.W
Joined: 09 Mar 2006 Posts: 6637
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Link Posted: Thu Oct 08, 2009 7:47 am Post subject: |
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Just wanted to say Hi Steve.
Good luck with the EMI tape !
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HK-Steve
Joined: 15 Jul 2006 Posts: 849 Location: Switzerland
TV/Projector: Marquee 9500, Epson 8100
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Link Posted: Thu Oct 08, 2009 10:38 am Post subject: |
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Hey Tom, Thanks for the Hello. Right back at You, Hope all is Well.
I have some other parts on order which should come in early next week,
fingers crossed the modifications work as I expect.
The EMI tape will do the same as the intermark stuff. I still might buy some of the intermark just to try out.
I am also looking into the Magnefilm, would be interesting to play with.
Cheers
Steve
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Nashou66
Joined: 12 Jan 2007 Posts: 16171 Location: West Seneca NY
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Link Posted: Thu Oct 08, 2009 12:45 pm Post subject: |
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HK-Steve wrote: | Hey Tom, Thanks for the Hello. Right back at You, Hope all is Well.
I have some other parts on order which should come in early next week,
fingers crossed the modifications work as I expect.
The EMI tape will do the same as the intermark stuff. I still might buy some of the intermark just to try out.
I am also looking into the Magnefilm, would be interesting to play with.
Cheers
Steve |
Yes the Magnefilm might be what to use inside the Tube housing and it might be nice on the back of the VNB right on the PCB. I think it be good to put above the Vim as well, I have a piece of steel cut to the size of the MDM slot covered with copper flashing and a ground wire above the Vim now. There is lots we can do to stop airborn EMI and RF but you have to ask, how far should we go and how much does it help? this is where a EMI/RF/Guass meter would help.
Athanasios
_________________ Don't blame your underwear for your crooked ass~ unknown Greek philosopher
"Republicans believe every day is the Fourth of July, but the Democrats believe every day is April 15." --- President Reagan
One Smart Dog!!!
Marquee High Performance Bellows now shipping!!
Marquee Modifications and Performance Enhancement
Marquee C-element and Bellow removal
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1031
Joined: 22 Mar 2006 Posts: 657 Location: Finland
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Ohmess
Joined: 11 Sep 2008 Posts: 242 Location: Vienna, VA
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Link Posted: Thu Oct 08, 2009 1:44 pm Post subject: EMI Tape |
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Would any of the 3M tapes be appropriate? Newark carries them.
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