Date   

Re: Tektronix 1230 Logic Analyzer

Nguyen Van Minh Danh
 

Hi Lyle,


Thanks for the videos. I did come across the Youtube videos on the 1230 and the TLA manual that you posted too. :)


My logic analyzer seems to be working, except that the battery to keep the RTC time is dead (need to replace it soon). For now I am looking for user manual and the PC software to study the possibility of transferring the data to PC.


Hopefully other members will provide more information.



Re: Tektronix 1230 Logic Analyzer

Lyle Bickley
 

On Sun, 12 Jan 2014 20:21:50 -0800
Lyle Bickley <lbickley@...> wrote:

On 12 Jan 2014 20:05:41 -0800
<mdanh2002@...> wrote:

Hi,

I got this Tektronix 1230 logic analyzer for a cheap price from a
Singapore electronics equipment seller. It comes with no probes or
manual, just the unit. After a month of searching, I managed to
purchase the probes from eBay and now I am waiting for its arrival.
However I am still looking for the manual for this unit and the PC
software for remote control via RS232-C. I believe the PC software
for this unit is called as S43R101 by Tektronix. A Google search
reveals very little useful information, apart from this PDF
http://www.mgoodguy.com/specs/TEK1230.pdf
http://www.mgoodguy.com/specs/TEK1230.pdf which contains some basic
description on its features and part numbers, and another post on
the Microchip forum http://www.microchip.com/forums/m81437.aspx
http://www.microchip.com/forums/m81437.aspx from somebody who was
looking for the same. Any help is appreciated! Thanks.
Here's the "Quick Start User Manual" - which won't help service it,
but will help in using it:

http://engineering.unt.edu/electrical/sites/default/files/Tektronix%20Logic%20Analyzer%20TLA%20502.pdf
Oops, I goofed - somehow I ended up with a TLA analyzer.

Here's a couple of Tektronix Youtube training videos on the Tek 1230:

Part 1
https://www.youtube.com/watch?v=XETdhRQp1lA

Part 2
https://www.youtube.com/watch?v=fez6GqI6yxs

Lyle

--
Bickley Consulting West Inc.
http://bickleywest.com

"Black holes are where God is dividing by zero"


Soldering and epoxying aluminium

Robin Whittle
 

For the benefit of people searching the archives, this message is partly
to signal that some recent messages in the thread: "Re: About the cable
used in oscilloscope probes" concerned techniques for soldering
aluminium and also to mention my technique for epoxying it.

John Byers reported a technique of soldering the aluminium pieces
immersed in oil, which I found most surprising. wyzkydd2358@...
wrote of simply using an ordinary soldering iron in a way which excluded
air and roughened the surface. Don Black mentioned that aluminium
loudspeaker coil wires could be soldered with an ultrasonic solder pot.

This arose from a discussion of soldering nichrome wire, which is
apparently used for the centre conductor of oscilloscope probe leads.
David Whess suggested treating the unsolderable metal with hydrochloric
acid and then electroplating copper.

Here is a technique I have used a few times. I mix up some "24 hour
Araldite" - two part retail epoxy which takes about 24 hours at room
temperature to set.

I abrade both surfaces with emery paper ("wet and dry"), apply some
epoxy and then abrade some more. This removes the oxide layer and lets
fresh epoxy bond to the metal. At this point the formerly clear,
somewhat yellow, epoxy becomes opaque and grey.

Then the two surfaces can be brought together. Popping the item in a
not too hot oven for half an hour or so will harden the epoxy without
having to wait a day.

Perhaps this would work with silver-loaded conductive epoxy to make an
electrically conductive joint.

- Robin http://www.firstpr.com.au/tequip/


Re: Tektronix 1230 Logic Analyzer

Lyle Bickley
 

On 12 Jan 2014 20:05:41 -0800
<mdanh2002@...> wrote:

Hi,

I got this Tektronix 1230 logic analyzer for a cheap price from a
Singapore electronics equipment seller. It comes with no probes or
manual, just the unit. After a month of searching, I managed to
purchase the probes from eBay and now I am waiting for its arrival.
However I am still looking for the manual for this unit and the PC
software for remote control via RS232-C. I believe the PC software
for this unit is called as S43R101 by Tektronix. A Google search
reveals very little useful information, apart from this PDF
http://www.mgoodguy.com/specs/TEK1230.pdf
http://www.mgoodguy.com/specs/TEK1230.pdf which contains some basic
description on its features and part numbers, and another post on the
Microchip forum http://www.microchip.com/forums/m81437.aspx
http://www.microchip.com/forums/m81437.aspx from somebody who was
looking for the same. Any help is appreciated! Thanks.
Here's the "Quick Start User Manual" - which won't help service it, but
will help in using it:

http://engineering.unt.edu/electrical/sites/default/files/Tektronix%20Logic%20Analyzer%20TLA%20502.pdf

Lyle
--
Bickley Consulting West Inc.
http://bickleywest.com

"Black holes are where God is dividing by zero"


Tektronix 1230 Logic Analyzer

Nguyen Van Minh Danh
 

Hi,

I got this Tektronix 1230 logic analyzer for a cheap price from a Singapore electronics equipment seller. It comes with no probes or manual, just the unit. After a month of searching, I managed to purchase the probes from eBay and now I am waiting for its arrival. However I am still looking for the manual for this unit and the PC software for remote control via RS232-C. I believe the PC software for this unit is called as S43R101 by Tektronix.

A Google search reveals very little useful information, apart from this PDF http://www.mgoodguy.com/specs/TEK1230.pdf which contains some basic description on its features and part numbers, and another post on the Microchip forum http://www.microchip.com/forums/m81437.aspx from somebody who was looking for the same.

Any help is appreciated! Thanks.


Re: About the cable used in oscilloscope probes

hpxref
 

<Aluminum can be easily soldered using regular old leaded solder
<using the right trick. You don't even need any special flux. Take
<your soldering iron and dab some fresh solder on so there's a
<ball of molten solder hanging from the tip and apply it to the
<aluminum to be soldered. Using the iron's tip lightly abrade the
<aluminum surface with a scraping motion, and the oxide layer will
<be wiped right off, allowing the solder to properly adhere.
----------------------------------------------------------------------------------
Yes, and you need a pretty solid tip on the iron too!
Another method :
When a 15 yo I bought a Sunbeam Twin 500cc motorcycle from a local
astronomer "dirt cheap"as it had a crack right round the aluminium
gear box casing where the lay-shaft bearing mount was.

Just owning a big bike was a big thrill for me as a 15 year old even if it couldn't be
ridden...then I was told of an old guy , an ex RAF aircraft mechanic who
had worked on antique planes in the UK and who was soldering up aluminum baffle
plates inside Al tanks for a local firm
I watched him fix my gearbox by taking the casing apart, cleaning it and immersing
it in light grade motor oil...then applying a HUGE soldering iron to it,
carefully soldering around the crack with the iron immersed in the oil as well
The oil prevented oxides from forming
It worked and (unlicensed) rode that bike around for weeks until I crashed it.
(Even after running into a power pole the repair was still OK)
Ive since soldered the seams of bent up small alum chassis together using a 150W "Scope"soldering iron
so can vouch for the method...messy and smelly, but worked "seamlessly"
Sometimes just coating the alum with oil works too for small jobs , but immersing seems always better
John


Re: 7Bxx MOD515C

 

Hi Steve,

The edge fingers of the circuit board are not good enough to support really HF signals. Tek had to modify them with floating edge connectors for the vertical deflection signals of the 7904, and later the 7104, to achieve the greater bandwidth these scopes needed. Even that design did not work above 1GHz which became the ultimate limit of the 7000 series.

 

I think you are mistaken about the holes. The 4 holes were a fundamental part of the 7000 plug-in rear molding by 1968 before production began in earnest on the 7000 series. This was 3 years before the 7A21N (which was designed to extend the bandwidth of the 7904 CRT) was designed in 1971.

 

Tek was already manufacturing the 576 with its fiber optic readout display which was one of the few bright spots (no pun intended) in the otherwise extremely expensive to manufacture, and therefore not very profitable, curve tracer. The fiber optic readout on the 576 was simple in comparison to what was needed for the 7000 series.  It was very late in the design phase of the 7000 when Barrie Gilbert, a relative newcomer at Tek, saw how Hiro was going to use the fiber optic readout concept on the 7000 series. It would have never worked reliably and it would have been a nightmare to support out in the field since the 7000 plug-ins already in late development by that time had many more possible readout combinations than Hiro could have handled with his system. The original fiber optic readout concept of the single purpose 576 was simple in comparison to what was needed for the much more versatile general purpose7000 series  laboratory oscilloscope.

 

Barrie Gilbert is not one to give up easily when he sees something he thinks is not going to work. The on-screen readout system he came up with was ideally suited to the technological advances in ICs that were taking place at Tek, and after demonstrating how his system would work to higher ups, Barrie got the OK to create the necessary ICs. When the 7000 series was introduced in 1969 HP ridiculed it as way over-priced and they derided the on-screen readout in a very unflattering ad as “bells and whistles”. Had Tek used Hiro’s fiber optic system it would have been even more expensive. Fortunately Barrie’s readout system proved to be extremely reliable and flexible enough to support the readout needs of 60+ different plug-ins. No one would even consider buying a scope today if it didn’t have on-screen readout.

 

As for the holes they have remained empty except for a very few exceptions. Almost all of the Tek production plug-ins do not use them. Not counting Mods (which are very different from Options) the 7A21N is the only exception I know of that Tek made which used the holes and it uses only two of the 4 holes. As Craig Sawyers pointed out they were used for position control DC levels on the 7A21N. I have a bunch of unusual plug-ins (all Mods) that use two of the 4 holes for special purposes. Rens’ plug-in (also a Mod) uses all 4 holes. That is the first one I have seen that uses all 4.

 

Unfortunately Mods (unlike options) were almost never documented since they were custom modifications.

 

In a sad, and bizarre note, Hiro was electrocuted many years ago while working on the wiring under his house. Barrie continues to develop amazing ICs to this day. He is a fellow at Analog Devices where he runs his own lab with a staff of IC designers not far from his home. He refuses to have anything to do with digital ICs. I hope to see him next month at the upcoming Rickreall swap meet.

 

Dennis Tillman W7PF

 

From: TekScopes@... [mailto:TekScopes@...] On Behalf Of ditter2@...
Sent: Sunday, January 12, 2014 9:03 AM
To: TekScopes@...
Subject: Re: [TekScopes] 7Bxx MOD515C

 



No, they were intended for exactly what they are used for in the 7A21N.  The 50 ohm connection through the edge fingers of the circuit board is good, but not great and has reflections that would not allow a really high frequency connection.

- Steve



Re: CRTs on Ebay

Michael A. Terrell
 

Ed, k1ggi wrote:

As a fledgling design engineer dealing with broadcast video, I attempted to purchase a copy of the fabled RS-170-A from the EIA in the late 70s.

The EIA lady who answered the phone said there was no such thing.

However, if you bought EIA Tentative Standard Number 1, you got two nice covers with a single 11x17 drawing in between, which had RS-170-A in the title block.

NTSC was the National Television System Committee.

On topic: I have and still use a 528A.
I've used the 528, but prefer the 529 that I have. I also have several in the 17xx series.


Re: CRTs on Ebay

k1ggi
 

As a fledgling design engineer dealing with broadcast video, I attempted to purchase a copy of the fabled RS-170-A from the EIA in the late 70s.

The EIA lady who answered the phone said there was no such thing.

However, if you bought EIA Tentative Standard Number 1, you got two nice covers with a single 11x17 drawing in between, which had RS-170-A in the title block.

NTSC was the National Television System Committee.

On topic: I have and still use a 528A.

Ed


From: TekScopes@... [mailto:TekScopes@...] On Behalf Of snapdiode@...
Sent: Sunday, January 12, 2014 19:18 PM
To: TekScopes@...
Subject: Re: [TekScopes] CRTs on Ebay

 

 

That would be RS-170a.



NTSC had nothing to do with color. The 'National Television
Standards Committee' was created to select the monochrome standard, then
years later they worked to add color without abandoning the existing
monochrome televisions and transmitters. There was nothing wrong with
the clor standard. The problem was with network feeds, or stations that
didn't maintain their equipment properly. The networks were fed with
leased bandwidth over the AT&T microwave network, where any Bellcore
tech could screw with the chroma level or phase at any microwave tower.
VIR & VITS were added which eliminated that problem. The US is much
bigger than the UK, with stations scattered all over the nation, unlike
the UK with centralized transmitters.

If you saw a crappy image in a hotel, it was because they bought the
cheapest TVs they could find, and wouldn't have them repaired if they
got any picture at all. I was a TV broadcast engineer, and once
installed the video & RF wiring in a new motel while in the industrial
electronics business.

People would do the same. New color TV on sale for $149 would sell
out in hours, even if the chroma wasn't aligned properly at the Asian
factory. They wuld complain thatthe color wasn't right, after a new CRT
was installed, because they were so used to crap from a dying CRT. One
customer had the chroma wide open, making everything look like a cheap
comic book. He took a swig of cheap beer and said, "If I'm a payin' fer
color, Is gett'n my money's worth". You can't fix stupid.


Re: About the cable used in oscilloscope probes

EricJ
 

Aluminum can be easily soldered using regular old leaded solder using the right trick. You don't even need any special flux. Take your soldering iron and dab some fresh solder on so there's a ball of molten solder hanging from the tip and apply it to the aluminum to be soldered. Using the iron's tip lightly abrade the aluminum surface with a scraping motion, and the oxide layer will be wiped right off, allowing the solder to properly adhere.

On Jan 12, 2014 6:08 PM, David <davidwhess@...> wrote:
 

I assume then that the aluminum tabs on can capacitors are tinned in this way. I
always wondered how they did that.

I have also seen copper plated aluminum wire.

On Mon, 13 Jan 2014 10:34:38 +1100, you wrote:

>I don't know what is used now but in his sixties books GA Briggs of
>Wharfedale speaker fame mentions they tinned the aluminium voice coil
>wire using an ultrasonic solder pot. The ultrasonic energy causes
>cavitation that strips off the surface oxidation under the solder
>surface, excluding the air.
>I think it would likely work with nichrome too.
>
>Don Black.
>
>On 13-Jan-14 4:16 AM, David wrote:
>>
>> Difficult to solder metals can often be handled by cleaning and
>> etching with
>> hydrochloric acid and then depositing copper via electrolysis and an
>> easily
>> acquired solution of copper sulphate or copper nitrate. I would worry
>> about
>> strain relief of the wire at the edge of the solder joint though.
>>
>> 12 Jan 2014 09:01:51 -0800, you wrote:
>>
>> > . . .
>> >
>> > BTW, as the center conductor is nichrome, you can't solder it. The
>> connections at the terminations are usually crimped on the wire.
>> >
>> > - Steve


Re: CRTs on Ebay

snapdiode@...
 

That would be RS-170a.

NTSC had nothing to do with color. The 'National Television
Standards Committee' was created to select the monochrome standard, then
years later they worked to add color without abandoning the existing
monochrome televisions and transmitters. There was nothing wrong with
the clor standard. The problem was with network feeds, or stations that
didn't maintain their equipment properly. The networks were fed with
leased bandwidth over the AT&T microwave network, where any Bellcore
tech could screw with the chroma level or phase at any microwave tower.
VIR & VITS were added which eliminated that problem. The US is much
bigger than the UK, with stations scattered all over the nation, unlike
the UK with centralized transmitters.

If you saw a crappy image in a hotel, it was because they bought the
cheapest TVs they could find, and wouldn't have them repaired if they
got any picture at all. I was a TV broadcast engineer, and once
installed the video & RF wiring in a new motel while in the industrial
electronics business.

People would do the same. New color TV on sale for $149 would sell
out in hours, even if the chroma wasn't aligned properly at the Asian
factory. They wuld complain thatthe color wasn't right, after a new CRT
was installed, because they were so used to crap from a dying CRT. One
customer had the chroma wide open, making everything look like a cheap
comic book. He took a swig of cheap beer and said, "If I'm a payin' fer
color, Is gett'n my money's worth". You can't fix stupid.


Re: About the cable used in oscilloscope probes

snapdiode@...
 

Certanium made a solder for aluminum. Whatever it was, by the time I got it didn't work (it had a best by date), but the flux was angrily bubbling away.


Re: About the cable used in oscilloscope probes

 

I assume then that the aluminum tabs on can capacitors are tinned in this way. I
always wondered how they did that.

I have also seen copper plated aluminum wire.

On Mon, 13 Jan 2014 10:34:38 +1100, you wrote:

I don't know what is used now but in his sixties books GA Briggs of
Wharfedale speaker fame mentions they tinned the aluminium voice coil
wire using an ultrasonic solder pot. The ultrasonic energy causes
cavitation that strips off the surface oxidation under the solder
surface, excluding the air.
I think it would likely work with nichrome too.

Don Black.

On 13-Jan-14 4:16 AM, David wrote:

Difficult to solder metals can often be handled by cleaning and
etching with
hydrochloric acid and then depositing copper via electrolysis and an
easily
acquired solution of copper sulphate or copper nitrate. I would worry
about
strain relief of the wire at the edge of the solder joint though.

12 Jan 2014 09:01:51 -0800, you wrote:

. . .

BTW, as the center conductor is nichrome, you can't solder it. The
connections at the terminations are usually crimped on the wire.

- Steve


Re: CRTs on Ebay

Don Black <donald_black@...>
 

Hello Michael,
                    I agree with all you say, I'm aware that NTSC is the standards committee rather than the colour standard but NTSC is what the colour standard has become known as (at least outside the US).
I take your point about the US colour standard being capable of good results if all is well, however if you haven't experienced the two systems in operation you don't know just how much "hardier" and more stable the PAL system is. It takes truly awful reception to notice hue changes with PAL.
As I said, I have great respect for the development of the NTSC colour system , the fact it remained in use for so long speaks volumes.

Don Black.

On 13-Jan-14 10:49 AM, Michael A. Terrell wrote:
 

Don Black wrote:
>
> Thanks Craig, interesting comments. Actually I'm in Australia but
> worked on some C1958 Marconi prototype colour equipment. Very useful
> experience. The PAL is rock solid by comparison.
> Our colour service started in March 1975 using PAL. For a few years
> before that a few of us were watching some colour programs from tapes
> from the UK and England. The local signal processors stripped off all
> the colour burst used to lock the chroma circuits but with PAL you can
> recover lock signals from the chroma which wasn't filtered out.
> Philips hawked some prototype sets around the trade in the late
> sixties (trying to push colour introduction I think) and included a
> little chroma lock board to allow users to watch the program. It
> recovered the lock signal and just injected it into the chroma
> oscillator as a trigger but apart from just managing lock on a stable
> signal generator I never saw it successfully lock to an off-air
> program (It might have worked on a properly stabilised program?). I
> thought it would be better with an AFC phase locked loop and built up
> a few boards using it. They worked far better than I hoped and would
> always lock solidly to the weakest chroma. The quality off the tapes
> varied from excellent to colour snow but it always locked right up. So
> for a few years we watched just about anything that moved in colour.
> I've still got a board kicking around somewhere.
> I believe when they were developing what became he NTSC colour system
> in the US it was suggested it would be advantageous to switch one
> colour signal phase on alternative lines (same as PAL) but it wasn't
> considered worth it and didn't happen. The one line delay line really
> makes the PAL system and I guess there wouldn't have been a cheap 64µs
> delay line available. It was the development of the acoustic glass
> delay line that really made it viable. The same delay was later used
> in VCRs for dropout compensation. There is still some advantage of the
> PAL system without a delay line, the eye averages the colour errors
> but gives the Venetian blind effect.
>
> Don Black.
>
> On 13-Jan-14 12:36 AM, Craig Sawyers wrote:
>>
>> =====================
>> Have you ever worked with old NTSC gear Craig. Capable of good
>> results but
>> Never Twice Same Colour oh so true, especially compared to the
>> stability of
>> PAL.
>> Still a great development for its time which served well for over half a
>> Century.
>> Don Black.
>> =====================
>>
>> No Don - but worked quite a bit in the States at one point, and suffered
>> NTSC with arbitrary colours in hotel rooms many a time.
>>
>> That was the big advantage in the UK of being second instead of first in
>> analogue colour television, and PAL was devised to work around the phase
>> distortion colour artefacts of NTSC.
>>
>> There used to be similar acronyms for PAL and SECAM too.
>>
>> Oh yes here we are (google is your friend)
>>
>> SECAM - System Essentially Contrary to the American Method
>> PAL - Perfect At Last
>>
>> I don't know what digital TV is like in the US, but in the UK the only
>> complaint is that the audio level varies over very wide limits from
>> channel
>> to channel. Set it correctly for on channel and you can be near deafened
>> when swapping to another channel. That was never the case with
>> analogue TV,
>> which like FM radio had a dynamic range the led to fairly standard audio
>> levels, with the only exception being adverts which were (and still are)
>> compressed so that the perceived audio level is louder than the
>> programme.
>>
>> Craig
>>

NTSC had nothing to do with color. The 'National Television
Standards Committee' was created to select the monochrome standard, then
years later they worked to add color without abandoning the existing
monochrome televisions and transmitters. There was nothing wrong with
the clor standard. The problem was with network feeds, or stations that
didn't maintain their equipment properly. The networks were fed with
leased bandwidth over the AT&T microwave network, where any Bellcore
tech could screw with the chroma level or phase at any microwave tower.
VIR & VITS were added which eliminated that problem. The US is much
bigger than the UK, with stations scattered all over the nation, unlike
the UK with centralized transmitters.

If you saw a crappy image in a hotel, it was because they bought the
cheapest TVs they could find, and wouldn't have them repaired if they
got any picture at all. I was a TV broadcast engineer, and once
installed the video & RF wiring in a new motel while in the industrial
electronics business.

People would do the same. New color TV on sale for $149 would sell
out in hours, even if the chroma wasn't aligned properly at the Asian
factory. They wuld complain thatthe color wasn't right, after a new CRT
was installed, because they were so used to crap from a dying CRT. One
customer had the chroma wide open, making everything look like a cheap
comic book. He took a swig of cheap beer and said, "If I'm a payin' fer
color, Is gett'n my money's worth". You can't fix stupid.





This email is free from viruses and malware because avast! Antivirus protection is active.



Re: CRTs on Ebay

Michael A. Terrell
 

Don Black wrote:

Thanks Craig, interesting comments. Actually I'm in Australia but worked on some C1958 Marconi prototype colour equipment. Very useful experience. The PAL is rock solid by comparison.
Our colour service started in March 1975 using PAL. For a few years before that a few of us were watching some colour programs from tapes from the UK and England. The local signal processors stripped off all the colour burst used to lock the chroma circuits but with PAL you can recover lock signals from the chroma which wasn't filtered out. Philips hawked some prototype sets around the trade in the late sixties (trying to push colour introduction I think) and included a little chroma lock board to allow users to watch the program. It recovered the lock signal and just injected it into the chroma oscillator as a trigger but apart from just managing lock on a stable signal generator I never saw it successfully lock to an off-air program (It might have worked on a properly stabilised program?). I thought it would be better with an AFC phase locked loop and built up a few boards using it. They worked far better than I hoped and would always lock solidly to the weakest chroma. The quality off the tapes varied from excellent to colour snow but it always locked right up. So for a few years we watched just about anything that moved in colour. I've still got a board kicking around somewhere.
I believe when they were developing what became he NTSC colour system in the US it was suggested it would be advantageous to switch one colour signal phase on alternative lines (same as PAL) but it wasn't considered worth it and didn't happen. The one line delay line really makes the PAL system and I guess there wouldn't have been a cheap 64�s delay line available. It was the development of the acoustic glass delay line that really made it viable. The same delay was later used in VCRs for dropout compensation. There is still some advantage of the PAL system without a delay line, the eye averages the colour errors but gives the Venetian blind effect.

Don Black.

On 13-Jan-14 12:36 AM, Craig Sawyers wrote:

=====================
Have you ever worked with old NTSC gear Craig. Capable of good results but
Never Twice Same Colour oh so true, especially compared to the stability of
PAL.
Still a great development for its time which served well for over half a
Century.
Don Black.
=====================

No Don - but worked quite a bit in the States at one point, and suffered
NTSC with arbitrary colours in hotel rooms many a time.

That was the big advantage in the UK of being second instead of first in
analogue colour television, and PAL was devised to work around the phase
distortion colour artefacts of NTSC.

There used to be similar acronyms for PAL and SECAM too.

Oh yes here we are (google is your friend)

SECAM - System Essentially Contrary to the American Method
PAL - Perfect At Last

I don't know what digital TV is like in the US, but in the UK the only
complaint is that the audio level varies over very wide limits from channel
to channel. Set it correctly for on channel and you can be near deafened
when swapping to another channel. That was never the case with analogue TV,
which like FM radio had a dynamic range the led to fairly standard audio
levels, with the only exception being adverts which were (and still are)
compressed so that the perceived audio level is louder than the programme.

Craig

NTSC had nothing to do with color. The 'National Television Standards Committee' was created to select the monochrome standard, then years later they worked to add color without abandoning the existing monochrome televisions and transmitters. There was nothing wrong with the clor standard. The problem was with network feeds, or stations that didn't maintain their equipment properly. The networks were fed with leased bandwidth over the AT&T microwave network, where any Bellcore tech could screw with the chroma level or phase at any microwave tower. VIR & VITS were added which eliminated that problem. The US is much bigger than the UK, with stations scattered all over the nation, unlike the UK with centralized transmitters.

If you saw a crappy image in a hotel, it was because they bought the cheapest TVs they could find, and wouldn't have them repaired if they got any picture at all. I was a TV broadcast engineer, and once installed the video & RF wiring in a new motel while in the industrial electronics business.

People would do the same. New color TV on sale for $149 would sell out in hours, even if the chroma wasn't aligned properly at the Asian factory. They wuld complain thatthe color wasn't right, after a new CRT was installed, because they were so used to crap from a dying CRT. One customer had the chroma wide open, making everything look like a cheap comic book. He took a swig of cheap beer and said, "If I'm a payin' fer color, Is gett'n my money's worth". You can't fix stupid.


Re: 7Bxx MOD515C

Craig Sawyers <c.sawyers@...>
 

=======================
... except that the four holes in the rear panel are only 3.3mm (could be 1/8 inch though).
Either the rear panel has changed since the article (which is highly unlikely), or the size got converted incorrect. My money is on the last one...
=======================

Don't forget that Barrie Gilbert is British.

Craig


Re: About the cable used in oscilloscope probes

Don Black <donald_black@...>
 

I don't know what is used now but in his sixties books GA Briggs of Wharfedale speaker fame mentions they tinned the aluminium voice coil wire using an ultrasonic solder pot. The ultrasonic energy causes cavitation that strips off the surface oxidation under the solder surface, excluding the air.
I think it would likely work with nichrome too.

Don Black.

On 13-Jan-14 4:16 AM, David wrote:
 

Difficult to solder metals can often be handled by cleaning and etching with
hydrochloric acid and then depositing copper via electrolysis and an easily
acquired solution of copper sulphate or copper nitrate. I would worry about
strain relief of the wire at the edge of the solder joint though.

12 Jan 2014 09:01:51 -0800, you wrote:

> . . .
>
> BTW, as the center conductor is nichrome, you can't solder it. The connections at the terminations are usually crimped on the wire.
>
> - Steve





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Re: Changes at Sphere Research for 2014

magnustoelle
 

Good Day, Walter,

a personal word of thanks for taking your time for this upfront information. It is much appreciated.

Please allow me one suggestion: When you get to the clearance sale, please continue with considering international shipment for your international customers.
I am based nearby Munich, Germany, and while I would love to travel to Canada at one time, I simply cannot "swing-by" and shop at your place easily...

I am painfully aware that international shipment means more paperwork for you, and it seems only reasonable that this extra effort must be compensated for.

I have read over http://www.sphere.bc.ca/test/faq.html and I am aware that you are doing international shipment already, but my point is: Please keep it up. Pretty, please.

Thank you and good selling.

Cheers,

Magnus


Changes at Sphere Research Corp.

In 2014, Walter & Susan will both be 65, and this will trigger some changes at Sphere. Sphere has been supplying Tek, HP and Fluke equipment, repair info and service parts on the net for almost 20 years. We have been slowly phasing out the larger and bulkier equipment, and items like CRTs recently simply because of storage problems, we are completely out of space, and paying way too much for what we have.

In 2014, we will sell, give away or scrap ALL the remaining equipment, and offer only parts and some plug-ins after that time. We have to clear almost 2,000 square feet of rented space (about 5-6 tons), and that's the task for 2014. We are always happy to see visitors, and in spring, once the snow clears, our customers are welcome to come up and sort through many shelves of un-listed gear we will clear out. All will be very cheap, some will be free. You'll have to see for yourself. We also have hundreds of prime, original service manuals; they also need to go to make space, as we no longer do outside service. They will be dirt cheap. We can ship them, but they are heavy, so best to grab them in person.

We also have millions of components, both through hole and smd, from our design activities, and they need to go as well. We are donating large amount of inventory to schools, colleges and universities, so if you know of anybody that needs parts for their electronics programs, let us know. Sphere will close completely in the fall of 2019, or possibly before, if circumstances change, but that will be the latest. Domains, content and inventory will all be sold or gone by that point. Consider this an early warning alert.

In 2014, our direct phone support will be from >>8:30AM to 11:30am, PST<<, Monday through Friday. It is possible we will be able to provide coverage beyond that, but it's best to plan for morning calls, or live with voice mail. Needless to say, our e-mail is 24/7/365, and is really ideal for most things. Every week or so, we will post a batch of particularly useful Tek, hp and Fluke items to the various lists first, then ebay or our site, and if not gone quickly, we will break them up for parts or scrap them. Once these batches go, that will be it, the material will be gone. Please watch for them to avoid disappointment!

We love what we do, and our customers, but the cost so keeping so much material endlessly available is simply prohibitive, and we have to make the footprint a lot smaller. You can find us at: http://www.sphere.bc.ca/test/index.html

All the best,
Walter & Susan


Re: Tek 7854 Doesn't Come On After EPROM ROM Replacement

 

Yes, the single new A28 memory board replaces both the old A28 RAM board and the
old A31 ROM board.

If I was replacing just the old ROM board and leaving the old RAM board in
place, this is where I would start although I can see that the decoding would
need to be changed to disable the output on RAM accesses. At the least,
comparing both schematics will be helpful in figuring out the memory map and
decoding. I have done that once but I did not keep any notes.

I am not aware of any differences in the firmware versions.

On 12 Jan 2014 13:19:51 -0800, you wrote:

So, this single board *replaces* the ROM *and* RAM board... ? The ROM and RAM boards in my 7854 could be replaced by this single board? That's pretty cool, if that's what you meant.

P.


Re: Tek 7854 Doesn't Come On After EPROM ROM Replacement

Phil Peri
 

Hi David,


I did see those photos in an earlier message, but I think it was my error in reading your message:


> The more recent board replaces both the
> old ROM board and the old RAM board so

> it also provides the maximum supported
> RAM which is backed up by a battery

> instead of an external power connection.


So, this single board *replaces* the ROM *and* RAM board... ? The ROM and RAM boards in my 7854 could be replaced by this single board? That's pretty cool, if that's what you meant.



P.






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