Guest
On Thursday, 23 May 2019 02:07:49 UTC+1, Phil Allison wrote:
whoosh
whoosh
B
Bill Sloman
Guest
On Thursday, May 23, 2019 at 2:33:25 PM UTC+10, tabb...@gmail.com wrote:
NT does like to imagine that people have missed the point he was trying to make, when the reality is that he was so far off the point that his comment didn't apply.
--
Bill Sloman, Sydney
NT does like to imagine that people have missed the point he was trying to make, when the reality is that he was so far off the point that his comment didn't apply.
--
Bill Sloman, Sydney
B
Bill Sloman
Guest
On Thursday, May 23, 2019 at 2:34:26 PM UTC+10, tabb...@gmail.com wrote:
Or so NT likes to think. Or - to be more precise - imagines he "thinks".
With NT it's NT's self-image all the way down.
--
Bill Sloman, Sydney
Or so NT likes to think. Or - to be more precise - imagines he "thinks".
With NT it's NT's self-image all the way down.
--
Bill Sloman, Sydney
B
bitrex
Guest
On 5/22/19 7:40 PM, DecadentLinuxUserNumeroUno@decadence.org wrote:
A switching power supply is also an "analog power supply", I can't think
of many uses for a "power supply" that accepts 5 volts as input and
spits out 0b00000101 in binary code.
A switching power supply is also an "analog power supply", I can't think
of many uses for a "power supply" that accepts 5 volts as input and
spits out 0b00000101 in binary code.
Guest
On Thursday, 23 May 2019 07:13:07 UTC+1, Bill Sloman wrote:
thanks for the laugh.
And back in the filter you go.
thanks for the laugh.
And back in the filter you go.
J
Joerg
Guest
On 2019-05-22 16:39, Chris Jones wrote:
Indeed :-(
Maybe the number of people who are able to operate such scopes has
dropped into the noise. Which would not surprise me.
It could be like it is with Hammond tonewheel organs where production
stopped in 1975. Their sound is unsurpassed but luckily there are still
tons around. Restoration becomes tougher because they are old and most
of the more sensitive innards are mechanical parts. I needed a solid 20
hours to get one going again. Now the prices for used ones start to
rise. We just sold ours because my wife could not play it anymore due to
a wrist injury. In contrast to old pianos it found a buyer almost
instantly. Just like it is with Tektronix 2465 scopes.
Well, you can get cheaper ones:
https://www.amazon.com/Sinometer-Single-Channel-Oscilloscope-CQ5010C/dp/B00NB58FJE/
--
Regards, Joerg
http://www.analogconsultants.com/
Indeed :-(
Maybe the number of people who are able to operate such scopes has
dropped into the noise. Which would not surprise me.
It could be like it is with Hammond tonewheel organs where production
stopped in 1975. Their sound is unsurpassed but luckily there are still
tons around. Restoration becomes tougher because they are old and most
of the more sensitive innards are mechanical parts. I needed a solid 20
hours to get one going again. Now the prices for used ones start to
rise. We just sold ours because my wife could not play it anymore due to
a wrist injury. In contrast to old pianos it found a buyer almost
instantly. Just like it is with Tektronix 2465 scopes.
Well, you can get cheaper ones:
https://www.amazon.com/Sinometer-Single-Channel-Oscilloscope-CQ5010C/dp/B00NB58FJE/
--
Regards, Joerg
http://www.analogconsultants.com/
J
John Larkin
Guest
On Wed, 22 May 2019 07:57:10 -0700, Joerg <news@analogconsultants.com>
wrote:
A digital scope can do cool stuff. Adjustable holdoff, bandwidth, and
persistance help find patterns in noise. Sometimes FFT helps.
Single-shot really helps.
What would be cool is variable-frequency internal trigger, or even
some sort of PLL trigger. Triggering external from a signal generator,
and signal averaging, can be useful. I have a box with more jitter
than I'd expected, and we used a digital scope and a signal generator
trigger to discover that a large component of the jitter is
synchronous to very close to 1 MHz. The problem now is to figure out
why.
That's another way to look at a signal, the spectrum of the jitter.
Sort of what HP used to call "modulation domain."
--
John Larkin Highland Technology, Inc
lunatic fringe electronics
wrote:
A digital scope can do cool stuff. Adjustable holdoff, bandwidth, and
persistance help find patterns in noise. Sometimes FFT helps.
Single-shot really helps.
What would be cool is variable-frequency internal trigger, or even
some sort of PLL trigger. Triggering external from a signal generator,
and signal averaging, can be useful. I have a box with more jitter
than I'd expected, and we used a digital scope and a signal generator
trigger to discover that a large component of the jitter is
synchronous to very close to 1 MHz. The problem now is to figure out
why.
That's another way to look at a signal, the spectrum of the jitter.
Sort of what HP used to call "modulation domain."
--
John Larkin Highland Technology, Inc
lunatic fringe electronics
J
Joerg
Guest
On 2019-05-23 09:11, John Larkin wrote:
DSOs can do cool stuff but most of the time you have to know what you
are looking for. In most EMI situations that isn't the case. Often
clients had noise issues in signals, very faint, and the demodulated
signals didn't hold any clues. The noise just wasn't strong enough. This
is where an analog scope can excel. When you see the normal fuzz on the
trace slightly change in "texture" and then it dawns. "Oh, that looks
like Radar noise!".
Maybe use a spectrum analyzer and sniff around the system for a 1MHz
source. Especially on power rails but be careful when connecting as that
can fry an analyzer input. Needs a series cap and then resistor to
ground, and things have to be settled out. _No_ turning on or off while
the analyzer is connected.
Triggering from a generator is something any DSO can do. In a pinch use
Ch4 or whatever, feed in the generator signal there and trigger on it.
Then do vernier control on the frequency and find where the jitter stops
"walking". Then you'd know which frequency to hunt and now you can set
the spectrum analyzer bandwidth really low for good SNR and fast
reaction. Sometimes I even use zero sweep where is shows ampltude
changes instantly while doing the "system pat down".
For really tiny noise sources: Use a good shortwave receiver, set to the
frequency near 1MHz but 700-800Hz off, in single-sidband mode (SSB).
Make sure to pick the correct sideband as there is lower and upper (LSB
or USB). Don headphones, connect an EMCO or similar magnetic near field
loop and go fishing. This is usually where client engineers think I've
gone over the cliff and into voodoo land. But only until the problem is
found.
That is extremely hard with a DSO. Easier with analog scopes and a
darkened room.
--
Regards, Joerg
http://www.analogconsultants.com/
DSOs can do cool stuff but most of the time you have to know what you
are looking for. In most EMI situations that isn't the case. Often
clients had noise issues in signals, very faint, and the demodulated
signals didn't hold any clues. The noise just wasn't strong enough. This
is where an analog scope can excel. When you see the normal fuzz on the
trace slightly change in "texture" and then it dawns. "Oh, that looks
like Radar noise!".
Maybe use a spectrum analyzer and sniff around the system for a 1MHz
source. Especially on power rails but be careful when connecting as that
can fry an analyzer input. Needs a series cap and then resistor to
ground, and things have to be settled out. _No_ turning on or off while
the analyzer is connected.
Triggering from a generator is something any DSO can do. In a pinch use
Ch4 or whatever, feed in the generator signal there and trigger on it.
Then do vernier control on the frequency and find where the jitter stops
"walking". Then you'd know which frequency to hunt and now you can set
the spectrum analyzer bandwidth really low for good SNR and fast
reaction. Sometimes I even use zero sweep where is shows ampltude
changes instantly while doing the "system pat down".
For really tiny noise sources: Use a good shortwave receiver, set to the
frequency near 1MHz but 700-800Hz off, in single-sidband mode (SSB).
Make sure to pick the correct sideband as there is lower and upper (LSB
or USB). Don headphones, connect an EMCO or similar magnetic near field
loop and go fishing. This is usually where client engineers think I've
gone over the cliff and into voodoo land. But only until the problem is
found.
That is extremely hard with a DSO. Easier with analog scopes and a
darkened room.
--
Regards, Joerg
http://www.analogconsultants.com/
J
John Larkin
Guest
On Thu, 23 May 2019 09:38:50 -0700, Joerg <news@analogconsultants.com>
wrote:
This was assumed to be random, gaussian jitter. But with the scope
signal averaging some, and teasing the pulse rate, we can delicately
heterodyne what is actually a big periodic jitter contributor.
https://www.dropbox.com/s/gunkxsfa0ujbot3/Sync_Jitter.JPG?dl=0
(note the 50 ps/div sweep. Few analog scopes ever managed that.)
The board has a 40 MHz VCXO locked to a 10 MHz OCXO, and a Zynq SOC
with outboard DRAM and an army of PLLs inside. We see this heterodyne
jitter at trigger multiples of 1 MHz and 3.2 MHz. Yuk.
--
John Larkin Highland Technology, Inc
picosecond timing precision measurement
jlarkin att highlandtechnology dott com
http://www.highlandtechnology.com
wrote:
This was assumed to be random, gaussian jitter. But with the scope
signal averaging some, and teasing the pulse rate, we can delicately
heterodyne what is actually a big periodic jitter contributor.
https://www.dropbox.com/s/gunkxsfa0ujbot3/Sync_Jitter.JPG?dl=0
(note the 50 ps/div sweep. Few analog scopes ever managed that.)
The board has a 40 MHz VCXO locked to a 10 MHz OCXO, and a Zynq SOC
with outboard DRAM and an army of PLLs inside. We see this heterodyne
jitter at trigger multiples of 1 MHz and 3.2 MHz. Yuk.
--
John Larkin Highland Technology, Inc
picosecond timing precision measurement
jlarkin att highlandtechnology dott com
http://www.highlandtechnology.com
B
Bill Sloman
Guest
On Thursday, May 23, 2019 at 11:46:00 PM UTC+10, tabb...@gmail.com wrote:
NT protects his self-image from comments that don't reinforce it.
He doesn't learn anything from posts he doesn't read, but he never seems to have learned anything from the posts he responded to so it may be the right strategy for him.
Suits me. He won't respond to this.
--
Bill Sloman, Sydney
NT protects his self-image from comments that don't reinforce it.
He doesn't learn anything from posts he doesn't read, but he never seems to have learned anything from the posts he responded to so it may be the right strategy for him.
Suits me. He won't respond to this.
--
Bill Sloman, Sydney
J
Joerg
Guest
On 2019-05-23 12:00, John Larkin wrote:
[...]
Is there RAM bank paging or read/write chunks happening every usec, or
maybe every 321nsec? Communication with other boards?
In the end you'll have to find those sources. That is where near field
probes and a good receiver or spectrum analyzer come in handy. You'll
have to go over the whole board plus all its supply rails. Like crime
scene investigators looking for that lone shell casing in the dirt.
--
Regards, Joerg
http://www.analogconsultants.com/
[...]
Is there RAM bank paging or read/write chunks happening every usec, or
maybe every 321nsec? Communication with other boards?
In the end you'll have to find those sources. That is where near field
probes and a good receiver or spectrum analyzer come in handy. You'll
have to go over the whole board plus all its supply rails. Like crime
scene investigators looking for that lone shell casing in the dirt.
--
Regards, Joerg
http://www.analogconsultants.com/
J
John Larkin
Guest
On Thu, 23 May 2019 20:47:28 -0400, Phil Hobbs
<pcdhSpamMeSenseless@electrooptical.net> wrote:
I have 20 SD-series plugins on my book shelf. Figure maybe $14K each
in the mid 1990s.
--
John Larkin Highland Technology, Inc
picosecond timing precision measurement
jlarkin att highlandtechnology dott com
http://www.highlandtechnology.com
<pcdhSpamMeSenseless@electrooptical.net> wrote:
I have 20 SD-series plugins on my book shelf. Figure maybe $14K each
in the mid 1990s.
--
John Larkin Highland Technology, Inc
picosecond timing precision measurement
jlarkin att highlandtechnology dott com
http://www.highlandtechnology.com
J
John Larkin
Guest
On Thu, 23 May 2019 16:51:15 -0700, Joerg <news@analogconsultants.com>
wrote:
No luck so far! I could cut the jitter at least in half if I can track
down that clock leakage.
And I have to confess that that scope HAS a CRT. It's a 50 GHz digital
sampling scope with a magnetic deflection (vertical scan!) cathode ray
tube.
--
John Larkin Highland Technology, Inc
picosecond timing precision measurement
jlarkin att highlandtechnology dott com
http://www.highlandtechnology.com
wrote:
No luck so far! I could cut the jitter at least in half if I can track
down that clock leakage.
And I have to confess that that scope HAS a CRT. It's a 50 GHz digital
sampling scope with a magnetic deflection (vertical scan!) cathode ray
tube.
--
John Larkin Highland Technology, Inc
picosecond timing precision measurement
jlarkin att highlandtechnology dott com
http://www.highlandtechnology.com
P
Phil Hobbs
Guest
On 5/23/19 11:09 AM, Joerg wrote:
I have three Tek analogue scopes: the 475A and 2467 work, and the 466
storage scope doesn't. Fifteen or so years ago, I used to use a 2465A
quite a lot, but these days I mostly use DSOs. (*)
I still really like the 246x's triggering.
Cheers
Phil Hobbs
(*) a couple of TDS 784As (1 GHz 4GS/s), a TDS 694C (3 GHz 10 Gs/s), and
two 1180x sampling scope mainframes with about 20 plug-ins. Magic.
--
Dr Philip C D Hobbs
Principal Consultant
ElectroOptical Innovations LLC / Hobbs ElectroOptics
Optics, Electro-optics, Photonics, Analog Electronics
Briarcliff Manor NY 10510
http://electrooptical.net
http://hobbs-eo.com
I have three Tek analogue scopes: the 475A and 2467 work, and the 466
storage scope doesn't. Fifteen or so years ago, I used to use a 2465A
quite a lot, but these days I mostly use DSOs. (*)
I still really like the 246x's triggering.
Cheers
Phil Hobbs
(*) a couple of TDS 784As (1 GHz 4GS/s), a TDS 694C (3 GHz 10 Gs/s), and
two 1180x sampling scope mainframes with about 20 plug-ins. Magic.
--
Dr Philip C D Hobbs
Principal Consultant
ElectroOptical Innovations LLC / Hobbs ElectroOptics
Optics, Electro-optics, Photonics, Analog Electronics
Briarcliff Manor NY 10510
http://electrooptical.net
http://hobbs-eo.com
A
AK
Guest
On Thursday, May 23, 2019 at 8:10:10 PM UTC-5, John Larkin wrote:
Speaking of CRTs.
I just found out that my state does not let you put CRTS or TVs out for trash pickup because of the lead, mercury, etc.
A average TV can have 5 lbs of lead in the glass.
I could not find any free recyclers, they charge a fee.
Speaking of CRTs.
I just found out that my state does not let you put CRTS or TVs out for trash pickup because of the lead, mercury, etc.
A average TV can have 5 lbs of lead in the glass.
I could not find any free recyclers, they charge a fee.
Guest
>A CRT can't really measure anything accurately.
I dunno Man. Decades ago at my shop in a batch of tradeins I had a TV that had no sync. these came from what subsequently became one of the best shops in town, in fact I worked there for bout eight months and got sick of it. Anyway, EVEY transistor had been removed and checked. I would bet maybe five techs worked on it and they eventually resorted to that.
Well, I was about like 21 and getting GOOD. I found a video waveform on my Tek 422 that was 1.1 volts P-P instead of the 1.0 volts P-P called for on the print. Open one meg resistor, 12 cents, sold unit for around a hundred bucks. I think I had the job done in like 45 minutes and had like $25 into procuring it. Divvy that up into hours and it is pretty good for like 1982.
I like analog scopes in auto trigger or free run, I use them for DC. In things like audio and most brownwares you only need to know if a voltage it there. It is usually regulated just but now many turns on the SMPS transformer. (I don't care what whatshisface says, they ARE transformers)
But I would stick it on 20 v/div. or whatever and go through all the power supplies in notime. Audio outputs in am amp, checked in seconds.
If you know how to use it, in troubleshooting an analog scope is the fast track. I can check so many things so much faster it is ridiculous.
The few digital/LCD scopes I have seen don't do quite what an old conventional CRO does. First of all the CRO responds immediately. Twelve volts, fifteen volts, plus and minus sixty volts, you can see it all on the scope immediately and you also get to see if there is alot of ripple. If that trace is not sharp and flat you can switch it to AC and see the ripple.
Also, in CRT TVs with reactive scanning (most of them) I could find out if the flyback was bad in less than a minute on most of them. They put out alot of voltage and were kinda prone to failure, but many people replaced them when they were good. Guess who had to fix it now ? I knew FOR A FACT if it was bad. Within five minutes.
Because of an old style analog CRO type oscilloscope.
Yeah, my CROs got people back to watching their sitcoms and even funnier, the news, so I guess the term "sillyscope" isn't so far off...
Bottom line is my CROs made my life and lifestyle possible. I think I) was about 14 when i got my first one. It was a HUGE Hickok that I could barely carry and had like a 3" screen. THEN my Uncle who worked for IBM gave me a Tek 310 that had been removed from service. It was the coolest thing I ever had. then he gave me a 561A with a dual timebase plugin so I eventually figured out how to work that.
No readouts, no digital, no nothing, if I have to make a choice between a meter and a scope I will take the scope every time. If I have to I can make a scope act as an ohmmeter. Also an ESR meter for lytics.
Me and scopes is brothers.
I dunno Man. Decades ago at my shop in a batch of tradeins I had a TV that had no sync. these came from what subsequently became one of the best shops in town, in fact I worked there for bout eight months and got sick of it. Anyway, EVEY transistor had been removed and checked. I would bet maybe five techs worked on it and they eventually resorted to that.
Well, I was about like 21 and getting GOOD. I found a video waveform on my Tek 422 that was 1.1 volts P-P instead of the 1.0 volts P-P called for on the print. Open one meg resistor, 12 cents, sold unit for around a hundred bucks. I think I had the job done in like 45 minutes and had like $25 into procuring it. Divvy that up into hours and it is pretty good for like 1982.
I like analog scopes in auto trigger or free run, I use them for DC. In things like audio and most brownwares you only need to know if a voltage it there. It is usually regulated just but now many turns on the SMPS transformer. (I don't care what whatshisface says, they ARE transformers)
But I would stick it on 20 v/div. or whatever and go through all the power supplies in notime. Audio outputs in am amp, checked in seconds.
If you know how to use it, in troubleshooting an analog scope is the fast track. I can check so many things so much faster it is ridiculous.
The few digital/LCD scopes I have seen don't do quite what an old conventional CRO does. First of all the CRO responds immediately. Twelve volts, fifteen volts, plus and minus sixty volts, you can see it all on the scope immediately and you also get to see if there is alot of ripple. If that trace is not sharp and flat you can switch it to AC and see the ripple.
Also, in CRT TVs with reactive scanning (most of them) I could find out if the flyback was bad in less than a minute on most of them. They put out alot of voltage and were kinda prone to failure, but many people replaced them when they were good. Guess who had to fix it now ? I knew FOR A FACT if it was bad. Within five minutes.
Because of an old style analog CRO type oscilloscope.
Yeah, my CROs got people back to watching their sitcoms and even funnier, the news, so I guess the term "sillyscope" isn't so far off...
Bottom line is my CROs made my life and lifestyle possible. I think I) was about 14 when i got my first one. It was a HUGE Hickok that I could barely carry and had like a 3" screen. THEN my Uncle who worked for IBM gave me a Tek 310 that had been removed from service. It was the coolest thing I ever had. then he gave me a 561A with a dual timebase plugin so I eventually figured out how to work that.
No readouts, no digital, no nothing, if I have to make a choice between a meter and a scope I will take the scope every time. If I have to I can make a scope act as an ohmmeter. Also an ESR meter for lytics.
Me and scopes is brothers.
W
whit3rd
Guest
On Thursday, May 23, 2019 at 12:00:14 PM UTC-7, John Larkin wrote:
So, feed the Z axis of an analog scope with some of your suspect jitter
inducers, and look at X/Y plots where X = signal, Y = signal-through-a-delay-line.
and you have a fine analog sensor for that effect.
So, feed the Z axis of an analog scope with some of your suspect jitter
inducers, and look at X/Y plots where X = signal, Y = signal-through-a-delay-line.
and you have a fine analog sensor for that effect.
Guest
>When I was a kid, I'd set up a Lissajous display at parties. Yes, >I was a geek even then.
You too ? I was worse. I connected the stereo to the X and Y inputs.
It gets even better, I had an old round tube color TV and connected the plates of a tube amp I had to the yoke, well a spare yoke, the one for the TV was laying down in the cabinet - it is required to make the proper high voltage. And THEN I got even worse, I stated messing with the -Y amps and modulated the beams.
It was good at parties. You get your X-Y display off the stereo fine, it is monochrome. I had COLOR ! HAHAHA.
I actually thought of making a TV into a scope. there are problems with that idea. If you want a horizontal sweep rate of 15 KHz, you gotta pump like a thousand volts into that coil. It is inductive so if you want twice the speed you are likely to need about twice the voltage. In them old sets even the vertical takes a ton of voltage because it is so inductive.
In the old days almost everything was like that. They did lower the impedance of their yokes when we got into solid state, but still they were inductive.
In the Maganvox T-991 chassis the horizontal winding still took the usual 12.5 uS pulse to effect horizontal sweep. The vertical windings, at those frequencies for the vertical, were damnear resistive and got fed an actual sawtooth.
You look at the yoke in one of those, it is like "What, is wire like ten bucks a foot there ?". They abandoned that super low impedance vertical winding because it took more power dissipation in the vertical output. With the higher impedance they can drive it with a pulse and then a a controlled recovery to achieve linearity in the sweep. Sometimes voltage costs more, sometimes current costs more.
What I never had and I think I will get is a current probe for the scopes. Just a cheap one that works, I don't need that gigahertz shit.
Everything has a purpose. I work on scopes, CROs so I got me a VTVM. I also threw together a 10X probe for it so I can measure 15,000 volts. Those CROs have CRTs and they have high voltages on well, in a scope kinda both ends of the CRT. Yeah I gotta figure out how to actually calibrate that soon.
You too ? I was worse. I connected the stereo to the X and Y inputs.
It gets even better, I had an old round tube color TV and connected the plates of a tube amp I had to the yoke, well a spare yoke, the one for the TV was laying down in the cabinet - it is required to make the proper high voltage. And THEN I got even worse, I stated messing with the -Y amps and modulated the beams.
It was good at parties. You get your X-Y display off the stereo fine, it is monochrome. I had COLOR ! HAHAHA.
I actually thought of making a TV into a scope. there are problems with that idea. If you want a horizontal sweep rate of 15 KHz, you gotta pump like a thousand volts into that coil. It is inductive so if you want twice the speed you are likely to need about twice the voltage. In them old sets even the vertical takes a ton of voltage because it is so inductive.
In the old days almost everything was like that. They did lower the impedance of their yokes when we got into solid state, but still they were inductive.
In the Maganvox T-991 chassis the horizontal winding still took the usual 12.5 uS pulse to effect horizontal sweep. The vertical windings, at those frequencies for the vertical, were damnear resistive and got fed an actual sawtooth.
You look at the yoke in one of those, it is like "What, is wire like ten bucks a foot there ?". They abandoned that super low impedance vertical winding because it took more power dissipation in the vertical output. With the higher impedance they can drive it with a pulse and then a a controlled recovery to achieve linearity in the sweep. Sometimes voltage costs more, sometimes current costs more.
What I never had and I think I will get is a current probe for the scopes. Just a cheap one that works, I don't need that gigahertz shit.
Everything has a purpose. I work on scopes, CROs so I got me a VTVM. I also threw together a 10X probe for it so I can measure 15,000 volts. Those CROs have CRTs and they have high voltages on well, in a scope kinda both ends of the CRT. Yeah I gotta figure out how to actually calibrate that soon.
Guest
OK fucker (no offense) let's pick this apart a bit.
Back in the 1970s you went to an audio store and bought a stereo. It was usually two channels but sometimes four. Now a 5.1 amp is technically six channels. A 7.1 is eight.
So let's say that the average number of channels in audio equipment has doubled. As such, if they only sold half as many units then they have sold just as many amps.
Now we get to one of "those" questions. All amps are analog ? Well that is one way of looking at it but are you including totally digitally controlled class D amps ? Even though they put out an analog signal, does that prove they are analog ?
A compact disk, regular CD, all digital. They yelled it from every mountaintop. But the signal at the jacks in the back is definitely analog unless you are using the digital, like optical or SPDIF or what the fuck ever.
But say you got a CD player that only has analog outputs, left and right. Is it then an analog device ?
Enquiring minds want to know but don't really care, just have too much time on their hands.
T
Tim Williams
Guest
<jurb6006@gmail.com> wrote in message
news:2d704703-914e-4d4e-9232-173cf52c2457@googlegroups.com...
My Trinitron monitor has a multiconductor deflection winding, fairly beefy
stuff. From the yoke, 18ga wire comes off, down to a big round-pin
connector, with ample trace width and clearance on the board (including some
slots for creepage). The HOT is rated something like 20 or 30A peak, and
1500Vceo. I figure there's got to be in the vicinity of 1kVA circulating in
that circuit, at 106.2kHz tops, or thereabouts (which is at 1600 x 1200 x
85Hz overall).
It also has a seperate high voltage supply, because the sync range is just
so wide. Vertical deflection is a purpose-made chip, which can run up to
144Hz or something like that (of course, the resolution isn't very good up
there).
The video outputs are interesting. The driver is monolithic, one of those
integrated cascode + buffer chips, around 100MHz BW into a high impedance,
and almost 100V swing. There's ESD clamp diodes, 22 ohm carbon comp
resistors and GDTs on the CRT neck board. Which may seem like kind of a
lot, but consider that internal flashover is essentially 30kV machine model
ESD, fucking brutal! Getting that much bandwidth while withstanding that
kind of abuse, is not at all a small feat.
AFAIK, the best they ever made, went up to 2048 x 1536 x 85Hz -- even more
video bandwidth, and more deflection [reactive] power, and even tighter
precision in linearity correction and electron optics. Amazing piece of
work! Just, not so competitive against modern equivalents...
Tim
--
Seven Transistor Labs, LLC
Electrical Engineering Consultation and Design
Website: https://www.seventransistorlabs.com/
news:2d704703-914e-4d4e-9232-173cf52c2457@googlegroups.com...
My Trinitron monitor has a multiconductor deflection winding, fairly beefy
stuff. From the yoke, 18ga wire comes off, down to a big round-pin
connector, with ample trace width and clearance on the board (including some
slots for creepage). The HOT is rated something like 20 or 30A peak, and
1500Vceo. I figure there's got to be in the vicinity of 1kVA circulating in
that circuit, at 106.2kHz tops, or thereabouts (which is at 1600 x 1200 x
85Hz overall).
It also has a seperate high voltage supply, because the sync range is just
so wide. Vertical deflection is a purpose-made chip, which can run up to
144Hz or something like that (of course, the resolution isn't very good up
there).
The video outputs are interesting. The driver is monolithic, one of those
integrated cascode + buffer chips, around 100MHz BW into a high impedance,
and almost 100V swing. There's ESD clamp diodes, 22 ohm carbon comp
resistors and GDTs on the CRT neck board. Which may seem like kind of a
lot, but consider that internal flashover is essentially 30kV machine model
ESD, fucking brutal! Getting that much bandwidth while withstanding that
kind of abuse, is not at all a small feat.
AFAIK, the best they ever made, went up to 2048 x 1536 x 85Hz -- even more
video bandwidth, and more deflection [reactive] power, and even tighter
precision in linearity correction and electron optics. Amazing piece of
work! Just, not so competitive against modern equivalents...
Tim
--
Seven Transistor Labs, LLC
Electrical Engineering Consultation and Design
Website: https://www.seventransistorlabs.com/