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Default RCA P60928 convergence

Looking for how to get into the menu for fine adjustment of convergence on a rca P60908. Thank Ted
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On Monday, November 14, 2016 at 10:38:24 AM UTC-5, wrote:
Looking for how to get into the menu for fine adjustment of convergence on a rca P60908. Thank Ted


Chassis is PTK195NT
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Oh boy, that's a blast from the past.

First a couple of comments after I tell you - I do not remember it all. First of all it is a very good point to point system. Second of all I would NEVER give this info out back when these things were being serviced still because they are very stable and you usually never have to touch them unless you change a CRT. (or possibly the whole convergence unit due to a coolant leak) So therefore you need to tell me WHY you need to do this. Did you change a CRT ? Did you transplant a projection box into a different cabinet ? Did you change te convergence module ?

WARNING - these things save settings on the fly. If you discover it is not responding correctly aqnd you did something wrong there is NO going back even if you unplug it. Unnastand ?? If it does not respond correctly that makes it harder to fix because as you do the actual repair you do not know if you have it fixed or not.

And to even do it you need an original remote or a select few universals (RCA from that era) or you simply cannot. newer RCA remotes even for the older newer ones won't do it.

Oh, and one other reason to do it is if you replaced the flyback with an aftermarket part, they have shorter retrace time and affect geometry, specifically the horizontal width. In that case, stay out of the convergence and just adjust the chassis width until the vertical lines converge at the sides.. That is easier even though you have a different problem - the main service menu is not labelled. You need the list of parameters. Otherwise you are liable to change something you do not want to change. I don't remember how many there are but there are enough not to memorize. I could determine it o the fly, by adjusting each one and returning it to its original parameter, which they give you on the right side. On the left you get "P:_" which is the parameter, on the right you get "V:_" which is the numerical value of that parameter. Those also save on the fly.

Tell e why you need to adjust this and I will search my PC for the files, if I even still have them. But I can retrieve quite a bit from memory.

Those things are a fantastic design, if they had not been obsoleted by flat screens ad those eljunko LCDs and DLPs they would be worth putting money into today. Their only big problem is the power supply on the main chassis. When the main chopper blows it takes out so many (SMD)parts it is simply not worth it. I have actually cut the PC board in that area and inserted a PS from another unit, which is actually not all that hard but has to be done right. You have to know where to cut.

So, what is the symptom/situation ?
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On Monday, November 14, 2016 at 10:38:24 AM UTC-5, wrote:
Looking for how to get into the menu for fine adjustment of convergence on a rca P60908. Thank Ted


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On Monday, November 14, 2016 at 10:38:24 AM UTC-5, wrote:
Looking for how to get into the menu for fine adjustment of convergence on a rca P60908. Thank Ted


I have the procedure, but I don't like folks running around in the service menu. This TV was very well designed but one parameter bumped too far and out she goes.

Later versions of the 195 had a limited point to point convergence in the customer menu. This was very similar to the service menu procedure but wouldn't allow you to play deep in the corners in order to avoid overstressing the conv outputs. See if your model has this.



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On Monday, November 14, 2016 at 6:01:59 PM UTC-5, wrote:
On Monday, November 14, 2016 at 10:38:24 AM UTC-5, wrote:
Looking for how to get into the menu for fine adjustment of convergence on a rca P60908. Thank Ted


I have the procedure, but I don't like folks running around in the service menu. This TV was very well designed but one parameter bumped too far and out she goes.

Later versions of the 195 had a limited point to point convergence in the customer menu. This was very similar to the service menu procedure but wouldn't allow you to play deep in the corners in order to avoid overstressing the conv outputs. See if your model has this.


I still want to know why he wants in there. There are only so many reasons, as you most probably know. they do not just drift. Is it just one color ? If so, beat around the convergence board for loose connections and if anything moves, solder it. If it is two colors, look into the main chassis geometry. If it is all three colors then does it have pincushion distortion ? I so the convergence PS is not starting and that is because of a rectifier and filter on there, and many times that failure is a coolant leak. Sometimes though it is just a filter cap. That source runs off the flyback IIRC and that is the only place they could have tapped it off because the main SMPS runs all the time.

I agree, no divulging such information unless they demonstrate they are either a tech that understands not to try to adjust out a problem or at least someone who can comprehend it. And I still want a reason why. THEY DO NOT DRIFT !

Actually if you remember, NAP eventually gave the customer much more multipoint convergence control. And they would try to adjust out faults related to the STKs, some of them did't just short out. (remember those ? you just unplug that one plug and hear HV and you knew what it was)But after the repair I saw all kinds of things people did, fortunately they provided a factory restore and that usually fixed whatever damage they did to the data. Those RCAs had no such feature. Let that be a lesson in trepidation to this person. You can't just come in here asking for that. I do not prefer to help people screw things up.

Know what you NEVER want to tell anyone, even a competent tech ? How to get into a Pioneer. Those menus are so unfriendly I left them alone whenever possible. I fact I left them all alone if possible. None of this stuff drifts. Greyscale maybe but still on some units forget even that.
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Thank you for your concern. You are correct the picture convergence is actually very good. Just off a very little bit at the very bottom of the screen.. Not the end of the world but would be nice to make it perfect seems to be just the bottom corners off a little bit. The v regulator on the power supply for the convergence board was replaced by me about 4 years ago. That may be why it is off. Thanks Ted
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On Monday, November 14, 2016 at 10:38:24 AM UTC-5, wrote:
Looking for how to get into the menu for fine adjustment of convergence on a rca P60908. Thank Ted


Also as far as experience I am a arcade game tech I have done convergence and tube swaps on many monitors and know enough to mark the rings before I start. I do not have much experience with projections and the electronic adjustment. I would start by making a single adjustment before going crazy. I don't know what the adjustment screen looks like at all. If there are values on screen I would wright them down before changing anything. I am not looking to screw anything up that's why I am here getting advice from you guys.. Thanks Ted
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On Thursday, November 24, 2016 at 9:42:06 PM UTC-5, wrote:
On Monday, November 14, 2016 at 10:38:24 AM UTC-5, wrote:
Looking for how to get into the menu for fine adjustment of convergence on a rca P60908. Thank Ted


Also as far as experience I am a arcade game tech I have done convergence and tube swaps on many monitors and know enough to mark the rings before I start. I do not have much experience with projections and the electronic adjustment. I would start by making a single adjustment before going crazy. I don't know what the adjustment screen looks like at all. If there are values on screen I would wright them down before changing anything. I am not looking to screw anything up that's why I am here getting advice from you guys. Thanks Ted


You still haven't described the error or indicated why there is an error. This is paramount. The convergence amps are like transconductance amps and their gain is set by precision resistors. Actually not even precision, but they are when you go to replace them.

There are no values to write down in the convergence. The lines move IF the amps are working. If they are not working the values change but you don't see it. That means that later, unless you literally took a picture of the error you could fix the amp and not know it is fixed. I **** to not.

On the NAP sets they gave the customer the access to do multipoint convergence and that can play hell on doing the actual troubleshooting. Luckily the included a "factory reset". There is no such thing on the PCA. Even if you unplug it the data are changed. Some sets have values and have normal old style controls but they're digital, like horizontal linearity, vertical bow and all that, and many of them do have a value (number) associated with each parameter. No so with the RCA, it is an advanced point to point system.

You shouldn't mark the rings, you should know how to set the rings. I wish you would describe the error and what all was done. If you changed the flyback you NEED not to set anything in the convergence because when the vertical lines converge at the sides you have set the width correctly. That is a totally different menu.

Fukit, since you are diligent I guess I will give you enough rope to hang yourself, to the best of my recollection. Remember you need the ORIGINAL remote. If you don't have that you are screwed anyway.

Lessee, how was that, on the set, not remote, hold down the menu button and hit power and then vol+. Release. With the vol+ advance the number on the right to 80 and then hit the ch+. This will bring up the test pattern. You will notice in the middle one color missing for the crosshairs, that is the adjustment point. Green is always the reference and is not generally set. If the crosshairs are magenta, you are adjusting red, if cyan you are adjusting blue.

On the remote the numbers 2,4,6,8 move the adjustment point, the arrow keys by the menu down below do the actual adjustment. And as I said before, it is saved IMMEDIATELY. If any point on the screen will not adjust STOP RIGHT THERE. Just get out the scope and troubleshoot. Don't even try to get it back. Your odds of that are about the same as Donald Trump winning the gold medal in Women's gymnastics.

If you have changed the flyback to an aftermarket and the vertical lines on the sides do not converge you need the main service menu, which is the same process but you go to V76 instead of V80. Now THAT you can do without the remote, plus there are values. You can adjust each one and return them to their original values until you find horizontal width. You will not have the internal test pattern though but you can use an external generator or a few other things. You can use preview guide from the cable box with the color turned all the way down for example. If you are in the V76 menu, DO NOT go up into the hundreds, those are tuner alignment and if you screw that up there is almost no way back. I can do it but I was one of the best on my day. When they offer you $30 an hour and to drive 96 miles a day to pick you up and drop you off every day that says something. So don't think something like that is easy. It is not that hard if you have what they call a "TAG" generator, but doing without is not all that easy. I could also align the recording circuits in a VCR without fancy equipment, the other tech saw how I did it and said "This guy is a genius". With a scope and a meter I can align almost anything except I can't figure out a way to set the separation on FM stereo without a real generator. But if I have to now all I need it one of those modulators they have so you can play your portable CD or MP3 player in a car that has no jacks for it.

So anyway, you have your rope. You know how to make the noose. I still highly recommend you describe the convergence error in detail. You could have a coolant leak which will destroy what may well be one of the best units RCA ever made. It leaks on the boards and after months becomes conductive and corrosive and the unit usually is unrepairable at any price.

I got the big bucks because I know what the **** I am doing. I remember one Mitsubishi came in with bad convergence and I did not really investigate enough. It wasn't that bad so I tried adjusting it and it would not. STOP I said to myself. Come to find out it was a broken mirror !

Which is another thing, on a sixty inch the mirror is usually retractable for moving. Is it in it's proper running position ? Check into the mounting of that before getting into the software.

You are not just dealing with electronics here, it is also optical. It is amazing how advanced they got before LCD technology blew it all off. If you've ever had a CRT out you see this ultraconcave glass in front of it which makes the coolant into a lens. It allows the lens to gather much more light from the CRT. The CRT puts out omnidirectionally, this concentrates it and improves efficiency quite a bit.

Mostly useless knowledge now.

So there's your rope. Don't come back whining that you hung yourself, you have been warned.
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Thank you for the info. I do know how to adjust the convergence rings not an expert but fairly good at it. It is always nice to have a place to go back to if things go wrong. As I stated in the other post The convergence is off very slightly in the very bottom of the screen. I also stated I replaced the power supply for the convergence board, I may have alse replaced the flyback at one point don't recall for sure at this point. I have no desire to screw up my very nice tv that is why I have come here to talk to the right people first before I do anything. Even if I end up not making the adjustments I still love getting the knowledge. Thanks again Ted


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On Saturday, November 26, 2016 at 10:06:12 AM UTC-5, wrote:
Thank you for the info. I do know how to adjust the convergence rings not an expert but fairly good at it.


There is *NO* need to touch those rings unless a CRT or yoke was replaced. Doing so will most likely throw off the DC idle current enough to cause the convergence outputs to run hot.

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On Saturday, November 26, 2016 at 3:18:39 PM UTC-5, wrote:
On Saturday, November 26, 2016 at 10:06:12 AM UTC-5, wrote:
Thank you for the info. I do know how to adjust the convergence rings not an expert but fairly good at it.


There is *NO* need to touch those rings unless a CRT or yoke was replaced.. Doing so will most likely throw off the DC idle current enough to cause the convergence outputs to run hot.


There's another thing people do not know. In a RPTV you do NOT set the rings (with the convergence unpowered) to converge in the middle. Depending on which way the CRTs are arranged you set green in the center and then red or blue to converge at 1/3 of the screen over from the left and the other color, red or blue to converge at 1/3 from the right.

See there's something I didn't mention, did not occur to me. That's one of the reasons we don't like divulging the information, you practically have to write a book. But believe it or not, that mis-centering takes a load off the convergence outputs. That is partly because they have put ALL the geometry on the convergence. It is also due to the inherent horizontal linearity correction need for the red and blue. The slight offset needed in the middle does not outweigh the fact that this scheme allows them to use a slightly lower voltage to the convergence outputs which lessens their dissipation.

Note that I was THE ****ING EXPERT in this state on these things. Seriously.. I can just about design one of these things but now that is a bunch of useless knowledge. My boss introduced me to someone as "The best tech in northeast Ohio" and I said "Northeast ?". He apologized later. But at the time it was my specialty and when it was where the money is at I made them a fortune. They got sick of the winters and moved to Florida. Next job the owner had a heart attack. I have never been fired from a good job. ****ty jobs yes, but not good ones.
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Thanks again for the info. I was actually referring to a regular pic tube not for projection. Thanks again. Ted
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On Sunday, July 16, 2017 at 4:24:40 PM UTC-4, wrote:
I need help




Minister, Rabbi, or Priest would be my best advice..


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I need help


If its that bad - you probably need to sort out the purity first.

I didn't think RCA PIL tubes still had those.

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On Monday, July 17, 2017 at 2:25:37 PM UTC-5, Ian Field wrote:
jamesgmail.com wrote in message
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I need help


If its that bad - you probably need to sort out the purity first.

I didn't think RCA PIL tubes still had those.


What is a PIL tube ?

The PTK series is rear projection, if a regular CRT it is CTC. The CTCs in regular direct views do not have any convergence in the menus, it is all done with rings and actually sometimes they don't even have them. They have a magnetic strip. It can be adjusted but is hard to get perfect. They also had bonded yokes so convergence adjustments were limited as well.

At the factory it was adjusted before the glue dried on the yoke, and they probably had a selection of different magnetic strips. I am also pretty sure they were adjusted by machine.
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wrote in message
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On Monday, July 17, 2017 at 2:25:37 PM UTC-5, Ian Field wrote:
jamesgmail.com wrote in message
news:1a527a6f-6b49-454e-8fa1-dd1f71088fc4googlegroups.com...
I need help


If its that bad - you probably need to sort out the purity first.

I didn't think RCA PIL tubes still had those.


What is a PIL tube ?


May have been a copyright dodge to avoid the Trinitron.

It was an early example of inline guns to avoid the hard work of purity and
convergence with delta gun layouts.

The phosphors were probably stripes like the Trinitron, but I think the
shadowmask had an array of staggered slots - the Trinitron shadowmask is
more like a Venetian blind.

I vaguely remember the RCA PIL tubes having bonded yokes, there may have
been purity rings on the tube neck, but purity was largely factory set.

Adjustment was much simpler with PIL tubes, and mostly done by careful
magnetics design.

A degaussing wand might help - but keep it away from the tube neck.

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On Tuesday, July 18, 2017 at 1:37:35 PM UTC-4, Ian Field wrote:
wrote in message
...
On Monday, July 17, 2017 at 2:25:37 PM UTC-5, Ian Field wrote:
jamesgmail.com wrote in message
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I need help

If its that bad - you probably need to sort out the purity first.

I didn't think RCA PIL tubes still had those.


What is a PIL tube ?


May have been a copyright dodge to avoid the Trinitron.



Perhaps, but I think most of Sony's engineering efforts were to avoid everyone else's patents. Their 70s power supply designs are a Rube Goldberg's nightmare wrapped in a chain saw wielding mass murderer's warm embrace. They weren't notably efficient or particularly well regulating, so my guess is that they were building a unique design with no patents (and really, who would patent such an abortion?).

I remember when NYC was reducing power during the 70s in an "energy saving" attempt. Well Sony power supplies committed harakiri at not much less than 100VAC, and lots of Trinitrons were blowing up during the brown-outs.

As far as in-line tubes, I remember seeing mid 60s GE Portacolor TVs use in-lines although I believe they were of delta configuration. Decent tube, easy to converge and outlasted the TV but the TV itself was a toilet. Terrible picture that would feature not only changing black level and AGC action but even change in color temperature as the brightness was advanced, and this was at the demodulators, not the CRT.

The Trinitron when it worked right produced some fabulous images, but I think the tube was very finicky and required far more stringent manufacturing tolerances than the typical tube, hence the cost. Give it a small nudge and the shadow mask would shift or one of the wires would snap. Early tubes had the coaxial second anode connector and those tubes would short internally.

Don't miss those days. (much)

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"John-Del" wrote in message
...
On Tuesday, July 18, 2017 at 1:37:35 PM UTC-4, Ian Field wrote:
wrote in message
...
On Monday, July 17, 2017 at 2:25:37 PM UTC-5, Ian Field wrote:
jamesgmail.com wrote in message
news:1a527a6f-6b49-454e-8fa1-dd1f71088fc4googlegroups.com...
I need help

If its that bad - you probably need to sort out the purity first.

I didn't think RCA PIL tubes still had those.

What is a PIL tube ?


May have been a copyright dodge to avoid the Trinitron.



Perhaps, but I think most of Sony's engineering efforts were to avoid
everyone else's patents. Their 70s power supply designs are a Rube
Goldberg's nightmare wrapped in a chain saw wielding mass murderer's warm
embrace. They weren't notably efficient or particularly well regulating,
so my guess is that they were building a unique design with no patents
(and really, who would patent such an abortion?).

I remember when NYC was reducing power during the 70s in an "energy
saving" attempt. Well Sony power supplies committed harakiri at not much
less than 100VAC, and lots of Trinitrons were blowing up during the
brown-outs.

As far as in-line tubes, I remember seeing mid 60s GE Portacolor TVs use
in-lines although I believe they were of delta configuration.


Its one or the other - delta is a bundle of guns and inline is exactly what
it says.



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On Wednesday, July 19, 2017 at 2:57:18 PM UTC-4, Ian Field wrote:
"John-Del" wrote in message
...
On Tuesday, July 18, 2017 at 1:37:35 PM UTC-4, Ian Field wrote:
wrote in message
...
On Monday, July 17, 2017 at 2:25:37 PM UTC-5, Ian Field wrote:
jamesgmail.com wrote in message
news:1a527a6f-6b49-454e-8fa1-dd1f71088fc4googlegroups.com...
I need help

If its that bad - you probably need to sort out the purity first.

I didn't think RCA PIL tubes still had those.

What is a PIL tube ?

May have been a copyright dodge to avoid the Trinitron.



Perhaps, but I think most of Sony's engineering efforts were to avoid
everyone else's patents. Their 70s power supply designs are a Rube
Goldberg's nightmare wrapped in a chain saw wielding mass murderer's warm
embrace. They weren't notably efficient or particularly well regulating,
so my guess is that they were building a unique design with no patents
(and really, who would patent such an abortion?).

I remember when NYC was reducing power during the 70s in an "energy
saving" attempt. Well Sony power supplies committed harakiri at not much
less than 100VAC, and lots of Trinitrons were blowing up during the
brown-outs.

As far as in-line tubes, I remember seeing mid 60s GE Portacolor TVs use
in-lines although I believe they were of delta configuration.


Its one or the other - delta is a bundle of guns and inline is exactly what
it says.


Yep, misspoke. The porta-color used an inline gun but retained the round RCA style shadow mask. When viewed up close, the round phoshpors looked a lot like the earlier delta. Later in-lines (including the Trini) used the rectangular slots that were quite obvious even when the TV was off.
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On Wednesday, July 19, 2017 at 4:53:41 PM UTC-5, John-Del wrote:
On Wednesday, July 19, 2017 at 2:57:18 PM UTC-4, Ian Field wrote:
"John-Del" wrote in message
...
On Tuesday, July 18, 2017 at 1:37:35 PM UTC-4, Ian Field wrote:
jurbmail.com wrote in message
...
On Monday, July 17, 2017 at 2:25:37 PM UTC-5, Ian Field wrote:
jamesgmail.com wrote in message
news:1a527a6f-6b49-454e-8fa1-dd1f71088fc4googlegroups.com...
I need help

If its that bad - you probably need to sort out the purity first.

I didn't think RCA PIL tubes still had those.

What is a PIL tube ?

May have been a copyright dodge to avoid the Trinitron.



Perhaps, but I think most of Sony's engineering efforts were to avoid
everyone else's patents. Their 70s power supply designs are a Rube
Goldberg's nightmare wrapped in a chain saw wielding mass murderer's warm
embrace. They weren't notably efficient or particularly well regulating,
so my guess is that they were building a unique design with no patents
(and really, who would patent such an abortion?).

I remember when NYC was reducing power during the 70s in an "energy
saving" attempt. Well Sony power supplies committed harakiri at not much
less than 100VAC, and lots of Trinitrons were blowing up during the
brown-outs.

As far as in-line tubes, I remember seeing mid 60s GE Portacolor TVs use
in-lines although I believe they were of delta configuration.


Its one or the other - delta is a bundle of guns and inline is exactly what
it says.


Yep, misspoke. The porta-color used an inline gun but retained the round RCA style shadow mask. When viewed up close, the round phoshpors looked a lot like the earlier delta. Later in-lines (including the Trini) used the rectangular slots that were quite obvious even when the TV was off.


It is totally possible to use inline guns with a triad type shadow mask. In fact it holds its shape better than the slit type mask. Plus, with such poor resolution (screen pitch) it looked better.

Those GEs with the AA and AB chassis' were not something I was in love with to say the least. Had to resolder all those feedthroughs. Plus they used a wafer tuner which is harder to clean properly.

I did make some money fixing them but you can't charge that much on those elcheapo sets.

Actually though, it was very rare that I had to replace any parts in them.
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wrote in message
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On Wednesday, July 19, 2017 at 4:53:41 PM UTC-5, John-Del wrote:
On Wednesday, July 19, 2017 at 2:57:18 PM UTC-4, Ian Field wrote:
"John-Del" wrote in message
...
On Tuesday, July 18, 2017 at 1:37:35 PM UTC-4, Ian Field wrote:
jurbmail.com wrote in message
...
On Monday, July 17, 2017 at 2:25:37 PM UTC-5, Ian Field wrote:
jamesgmail.com wrote in message
news:1a527a6f-6b49-454e-8fa1-dd1f71088fc4googlegroups.com...
I need help

If its that bad - you probably need to sort out the purity first.

I didn't think RCA PIL tubes still had those.

What is a PIL tube ?

May have been a copyright dodge to avoid the Trinitron.



Perhaps, but I think most of Sony's engineering efforts were to avoid
everyone else's patents. Their 70s power supply designs are a Rube
Goldberg's nightmare wrapped in a chain saw wielding mass murderer's
warm
embrace. They weren't notably efficient or particularly well
regulating,
so my guess is that they were building a unique design with no
patents
(and really, who would patent such an abortion?).

I remember when NYC was reducing power during the 70s in an "energy
saving" attempt. Well Sony power supplies committed harakiri at not
much
less than 100VAC, and lots of Trinitrons were blowing up during the
brown-outs.

As far as in-line tubes, I remember seeing mid 60s GE Portacolor TVs
use
in-lines although I believe they were of delta configuration.

Its one or the other - delta is a bundle of guns and inline is exactly
what
it says.


Yep, misspoke. The porta-color used an inline gun but retained the round
RCA style shadow mask. When viewed up close, the round phoshpors looked a
lot like the earlier delta. Later in-lines (including the Trini) used
the rectangular slots that were quite obvious even when the TV was off.


It is totally possible to use inline guns with a triad type shadow mask.
In fact it holds its shape better than the slit type mask. Plus, with such
poor resolution (screen pitch) it looked better.

Those GEs with the AA and AB chassis' were not something I was in love
with to say the least. Had to resolder all those feedthroughs. Plus they
used a wafer tuner which is harder to clean properly.

I did make some money fixing them but you can't charge that much on those
elcheapo sets.

Actually though, it was very rare that I had to replace any parts in them.


Never seen an RCA TV in the UK, and I think the GE ones were co produced
with Hitachi.

Thorn Consumer Electronics standardised on RCA PIL tubes for a while. There
was a lot of re badging about - so hard to keep track.

One of the setups with RCA tubes used a low voltage flyback system - it was
hard to get transistors that could handle the current.

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"Never seen an RCA TV in the UK, and I think the GE ones were co produced
with Hitachi. "

Here, Hitachi and RCA had quite the relationship. They built bigscreens for each other. You could open up an RCA and find a Hitachi or open up a Hitachi and find an RCA. The last two it seems were Mitsubishi and Sony if you actually wanted their product, everyone else eventually would just buy whatever and have it rebadged.

"One of the setups with RCA tubes used a low voltage flyback system - it was

hard to get transistors that could handle the current. "

Did not run into that problem. I did have some small Emersons that were hard to get a damper diode for because it was such high current. But not an RCA. But you said RCA tubes, that is not the fault of the tubes. It is the fault of the engineers.

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On Tuesday, 18 July 2017 21:42:52 UTC+1, John-Del wrote:
On Tuesday, July 18, 2017 at 1:37:35 PM UTC-4, Ian Field wrote:
wrote in message
...
On Monday, July 17, 2017 at 2:25:37 PM UTC-5, Ian Field wrote:
jamesgmail.com wrote in message
news:1a527a6f-6b49-454e-8fa1-dd1f71088fc4googlegroups.com...


What is a PIL tube ?


May have been a copyright dodge to avoid the Trinitron.


Perhaps, but I think most of Sony's engineering efforts were to avoid everyone else's patents. Their 70s power supply designs are a Rube Goldberg's nightmare wrapped in a chain saw wielding mass murderer's warm embrace. They weren't notably efficient or particularly well regulating, so my guess is that they were building a unique design with no patents (and really, who would patent such an abortion?).

I remember when NYC was reducing power during the 70s in an "energy saving" attempt. Well Sony power supplies committed harakiri at not much less than 100VAC, and lots of Trinitrons were blowing up during the brown-outs.


The Trinitron when it worked right produced some fabulous images, but I think the tube was very finicky and required far more stringent manufacturing tolerances than the typical tube, hence the cost. Give it a small nudge and the shadow mask would shift or one of the wires would snap. Early tubes had the coaxial second anode connector and those tubes would short internally.

Don't miss those days. (much)


I remember the PSU boards in 70s trinitron sets. Talk about unnecessarily complex. As an experiment I once replaced the PSU board with a lightbulb as a dropper. (I forget how I provided filament power.) It worked, though voltage instability caused picture height instability.

I liked those sets as they were well valued but CRT emission tended to go. No-one else had worked out how to get the emission back, I did.


NT


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wrote in message
...
"Never seen an RCA TV in the UK, and I think the GE ones were co produced

with Hitachi. "

Here, Hitachi and RCA had quite the relationship. They built bigscreens
for each other. You could open up an RCA and find a Hitachi or open up a
Hitachi and find an RCA. The last two it seems were Mitsubishi and Sony if
you actually wanted their product, everyone else eventually would just buy
whatever and have it rebadged.

"One of the setups with RCA tubes used a low voltage flyback system - it
was

hard to get transistors that could handle the current. "

Did not run into that problem. I did have some small Emersons that were
hard to get a damper diode for because it was such high current. But not
an RCA. But you said RCA tubes, that is not the fault of the tubes. It is
the fault of the engineers.


I only ever encountered the low voltage flyback system with certain RCA
tubes - and it was largely dictated by the design of the bonded on scan
yoke.

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Default RCA P60928 convergence



wrote in message
...
On Tuesday, 18 July 2017 21:42:52 UTC+1, John-Del wrote:
On Tuesday, July 18, 2017 at 1:37:35 PM UTC-4, Ian Field wrote:
wrote in message
...
On Monday, July 17, 2017 at 2:25:37 PM UTC-5, Ian Field wrote:
jamesgmail.com wrote in message
news:1a527a6f-6b49-454e-8fa1-dd1f71088fc4googlegroups.com...


What is a PIL tube ?

May have been a copyright dodge to avoid the Trinitron.


Perhaps, but I think most of Sony's engineering efforts were to avoid
everyone else's patents. Their 70s power supply designs are a Rube
Goldberg's nightmare wrapped in a chain saw wielding mass murderer's warm
embrace. They weren't notably efficient or particularly well regulating,
so my guess is that they were building a unique design with no patents
(and really, who would patent such an abortion?).

I remember when NYC was reducing power during the 70s in an "energy
saving" attempt. Well Sony power supplies committed harakiri at not much
less than 100VAC, and lots of Trinitrons were blowing up during the
brown-outs.


The Trinitron when it worked right produced some fabulous images, but I
think the tube was very finicky and required far more stringent
manufacturing tolerances than the typical tube, hence the cost. Give it
a small nudge and the shadow mask would shift or one of the wires would
snap. Early tubes had the coaxial second anode connector and those tubes
would short internally.

Don't miss those days. (much)


I remember the PSU boards in 70s trinitron sets. Talk about unnecessarily
complex. As an experiment I once replaced the PSU board with a lightbulb
as a dropper. (I forget how I provided filament power.) It worked, though
voltage instability caused picture height instability.

I liked those sets as they were well valued but CRT emission tended to go.
No-one else had worked out how to get the emission back, I did.


With monitors - I discovered that some 'genius' at Philips had published a
bulletin stated that stable SMPSUs meant CRT heaters only needed 6.15V. Most
manufacturers fell for it, and most CRTs ended up with poisoned cathodes.

There was plenty of evidence that some engineers were just turning the wick
up in the PSU. My solution was to fit a Shottky-barrier heater rectifier,
that needed an added snubber to prevent the flyback peaks killing the
rectifier, and improvements to the filter circuit. Some already had Sb
rectifier, so there wasn't much I could do.

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