| Author |
Message |
chicubs32
Joined: 09 Sep 2010
Posts: 4
Location: Virginia
|
| Posted: Fri Sep 24, 2010 2:30 pm Post subject: 808 barco need a quad |
|
|
|
anyone out there have a quad for sale? Not having a projector with football season is killing me.
|
|
| Back to top |
|
 |
Nashou66
Joined: 12 Jan 2007
Posts: 16171
Location: West Seneca NY
|
|
| Back to top |
|
|
secstate
Joined: 20 Mar 2006
Posts: 720
|
| Posted: Fri Sep 24, 2010 2:49 pm Post subject: |
|
|
|
Yeah they are beginning to be like that chip in the G90 rarer than hens teeth. Esenttially if Curt doesn't have one or you don't like his price you are pretty much left with purchasing another projector to get one (Other than MPs quad(s) for the 909 I cannot recall when I last saw a quad for sale individually). I have a spare but it is not for sale sorry but it came out of a projector I parted out. Also you might want to specify which quad you are looking for new or old style.
|
|
| Back to top |
|
|
Curt Palme
CRT Tech
Joined: 08 Mar 2006
Posts: 24396
Location: Langley, BC
TV/Projector: All of them!
|
| Posted: Fri Sep 24, 2010 2:54 pm Post subject: |
|
|
Barco has them... at $1200+ !!!!!
Put it this way: I bought 25 Barco 708 about 18 months ago, all with toasted tubes. I retubed one, parted out the rest.. and all those quads are long gone. Quads seem to go in batches.. sold about 6 last month, but when I'm robbing them out of sets I have for sale, I have to say I'm out of stock. It sucks, I know..
|
|
| Back to top |
|
|
chicubs32
Joined: 09 Sep 2010
Posts: 4
Location: Virginia
|
| Posted: Fri Sep 24, 2010 3:49 pm Post subject: |
|
|
I am looking for an old Quad. I am going to patiently wait and see if one comes up. 
|
|
| Back to top |
|
|
wingnut2001
Joined: 25 Aug 2010
Posts: 37
Location: Horse City of the world!
|
| Posted: Fri Sep 24, 2010 5:06 pm Post subject: |
|
|
|
join the club
|
|
| Back to top |
|
|
Tom.W
Joined: 09 Mar 2006
Posts: 6635
|
| Posted: Fri Sep 24, 2010 9:00 pm Post subject: |
|
|
I have an extra quad #R761743 that I believe came out an 808 retro but the high voltage cables come out the bottom instead of the side. Has anyone ever tried one of these in a standard 808 ?
Now that I think about I've never had to replace the quad in my 808 so maybe the HV leads are supposed to come out the bottom and not the side.....
|
|
| Back to top |
|
|
secstate
Joined: 20 Mar 2006
Posts: 720
|
| Posted: Fri Sep 24, 2010 10:57 pm Post subject: |
|
|
| Tom.W wrote: | I have an extra quad #R761743 that I believe came out an 808 retro but the high voltage cables come out the bottom instead of the side. Has anyone ever tried one of these in a standard 808 ?
Now that I think about I've never had to replace the quad in my 808 so maybe the HV leads are supposed to come out the bottom and not the side..... |
As I recall, it has been a while, the 808 quad wire comes out the top of the quad so assuming one of us has top or bottom confused that should work. Might work anyway. I run my 120x Barco with an 808 quad.
|
|
| Back to top |
|
|
Tom.W
Joined: 09 Mar 2006
Posts: 6635
|
| Posted: Fri Sep 24, 2010 11:15 pm Post subject: |
|
|
|
What I mean is the HV leads come out of the potting compound (same side as the mounting bracket) at 45 degrees relative to the potting compound.
|
|
| Back to top |
|
|
Tom.W
Joined: 09 Mar 2006
Posts: 6635
|
| Posted: Sat Sep 25, 2010 3:32 am Post subject: |
|
|
| Nashou66 wrote: | Man what is it with all these barco quads dyeing!!!
Athanasios |
Weren't the Spellman HV power supplies also impossible to fix but no longer made ? IF the quad fails in a Barco you better own a backup or your dead in the water until you do.
On the bright side the rest of the boards are becoming more available as people part out working projectors just for a quad....
|
|
| Back to top |
|
|
tse
Joined: 03 May 2006
Posts: 1014
Location: Sweatbucket, Fl.
|
| Posted: Sat Sep 25, 2010 11:51 pm Post subject: |
|
|
Does anyone know what is dieing in these? Is it the transformer or the multiplier section?
Scott
_________________
"Were we directed from Washington when to sow and when to reap, we would soon want bread."
Thomas Jefferson
|
|
| Back to top |
|
|
secstate
Joined: 20 Mar 2006
Posts: 720
|
| Posted: Sun Sep 26, 2010 2:09 pm Post subject: |
|
|
| tse wrote: | Does anyone know what is dieing in these? Is it the transformer or the multiplier section?
Scott |
I don't know that that has ever been determined there was a recent thread here that seemed to indicated it might be the transformer (some took apart a failed quad). The newer style quads appear to be somewhat more failure prone than the older style. I don't think, other than that recent thread anybody has looked at this closely.
|
|
| Back to top |
|
|
stefuel
Joined: 07 Mar 2006
Posts: 3353
Location: Green Harbor MA USA
|
| Posted: Sun Sep 26, 2010 2:34 pm Post subject: |
|
|
OK, somebody send me a blown quad.
Question, what is the difference between projector models quads and which ones are interchangable? Which ones are we most interested in fixing???
I assume it's called a "quadrupler" for a reason. The Transformer must output 8,750 volts and go through a multiplier (4X) section bringing it up to 35,000 volts?
If you test the transformer section's primary and secondary voltage and you get the correct and stable secondary voltage, then the problem must be in the multiplier section.
What is the primary voltage???
_________________
Chip
A Barco is only a AmPro with training wheels
Card carrying member of the AVS chain gang.
|
|
| Back to top |
|
|
Curt Palme
CRT Tech
Joined: 08 Mar 2006
Posts: 24396
Location: Langley, BC
TV/Projector: All of them!
|
| Posted: Sun Sep 26, 2010 3:33 pm Post subject: |
|
|
My theory on most (including the new style especially) is that the silicone starts conducting after a while. I've played a lot with this, and on many quads, heck, even some that still work, you can draw an arc through the silicone or back block part by touching it with a grounded screwdriver tip.
Some will short internally (caps, diodes, etc), but my guess is that the silicone is mainly to blame.
|
|
| Back to top |
|
|
tse
Joined: 03 May 2006
Posts: 1014
Location: Sweatbucket, Fl.
|
| Posted: Sun Sep 26, 2010 4:33 pm Post subject: |
|
|
| stefuel wrote: | OK, somebody send me a blown quad.
Question, what is the difference between projector models quads and which ones are interchangable? Which ones are we most interested in fixing???
I assume it's called a "quadrupler" for a reason. The Transformer must output 8,750 volts and go through a multiplier (4X) section bringing it up to 35,000 volts?
If you test the transformer section's primary and secondary voltage and you get the correct and stable secondary voltage, then the problem must be in the multiplier section.
What is the primary voltage??? |
The projectors all use tubes with similar HV needs. Voltage about +35kv, average current < 1ma, peak current > 3ma. That's per tube. So the HV supply has to be able to output 35kv @ 10ma for short periods of time and 35kv @ 3ma continuous. 350 watt power supply with cooling capacity for continuous 105 watts.
The input will be about 9000V (peak voltage) and will be multiplied by about 4 for the 35kv DC output. Think 3889 9V batteries connected in series. Yeehaw!
The multiplier's capacitor size is determined by the input switching frequency and output load. Smaller value (and size) caps can be used with higher input frequency. The HV type rectifiers limit the switching freq to something near 60kHz. Faster and they will burn up. All these supplies were designed many years ago. Faster HV rectifiers might be available now.
So, what I am saying is the multiplier sections are probably very similar. It would not surprise me that you could splice brand "S" multipliers to brand "B" flyback transformers.
Of course, the HV divider resistors for the regulators would have to be made compatable. Size and shapes would probably prevent direct installation in the same spaces.
Scott
_________________
"Were we directed from Washington when to sow and when to reap, we would soon want bread."
Thomas Jefferson
|
|
| Back to top |
|
|
tse
Joined: 03 May 2006
Posts: 1014
Location: Sweatbucket, Fl.
|
| Posted: Sun Sep 26, 2010 4:40 pm Post subject: |
|
|
| Curt Palme wrote: | My theory on most (including the new style especially) is that the silicone starts conducting after a while. I've played a lot with this, and on many quads, heck, even some that still work, you can draw an arc through the silicone or back block part by touching it with a grounded screwdriver tip.
Some will short internally (caps, diodes, etc), but my guess is that the silicone is mainly to blame. |
That makes it sound like one could rip the original rtv off of a good quad, prime it up, and pot it with some new silicone. Potting is not difficult but you do need a vacuum chamber and pump to pull the air bubbles out. If trying this on a bad quad you would have to change the bad parts and dig out the material where arcs have travelled to remove the (conductive) carbon that builds up along the arc path.
I have seen Spellman multipliers that have been repaired in the potted section. It can be done.
Scott
_________________
"Were we directed from Washington when to sow and when to reap, we would soon want bread."
Thomas Jefferson
|
|
| Back to top |
|
|
dvh99
Joined: 25 Dec 2009
Posts: 2158
Location: nederland
|
|
| Back to top |
|
|
stefuel
Joined: 07 Mar 2006
Posts: 3353
Location: Green Harbor MA USA
|
| Posted: Sun Sep 26, 2010 6:06 pm Post subject: |
|
|
| dvh99 wrote: | | http://www.epicresins.com/electrical_transformers.asp |
I was just looking here and the example for their product R3521/H5094 is a Beckett ignition transformer. Apprx 18,000 volts. That has curled my hair a couple of times 
_________________
Chip
A Barco is only a AmPro with training wheels
Card carrying member of the AVS chain gang.
|
|
| Back to top |
|
|
stefuel
Joined: 07 Mar 2006
Posts: 3353
Location: Green Harbor MA USA
|
| Posted: Sun Sep 26, 2010 6:12 pm Post subject: |
|
|
Remember when I told ya all that gasoline softened the LC tube coupling sealant? I wonder if it will soften potting material as well?
_________________
Chip
A Barco is only a AmPro with training wheels
Card carrying member of the AVS chain gang.
|
|
| Back to top |
|
|
Nashou66
Joined: 12 Jan 2007
Posts: 16171
Location: West Seneca NY
|
|
| Back to top |
|
|
|
|
