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Re: 7000 series on-screen displays boards
Of the three different readout boards that I now know of now, the 7844
uses the common one so it will be the easiest to find as it is on the less expensive 7000 series mainframes. I am surprised there is not already a list for this somewhere. On Fri, 26 Oct 2012 23:50:04 -0400, Michael Dunn <md@...> wrote: Thanks for all the info. I have a couple of 7844s in need of |
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Re: line voltage 7704a
The capacitors should be more important than the sense lines. They
provide part of each regulator's frequency and phase compensation. I would be suspicious if not hooking up the sense lines has an effect. They are all shunted to the main lines via low value resistors from 47 to 470 ohms. Could one or more of those resistors be partially open? Or maybe the pole-zero compensation in one of the regulators (resistor and capacitor in series like R3278/C3278 and R3289/C3289 in the -15 volt regulator) is bad. The -15 and -50 volt regulators are more liable to oscillate because their NPN output power stages have gain. They have extra frequency compensation of their output stages to help control that. On Fri, 26 Oct 2012 20:48:35 -0000, "Albert" <aodiversen@...> wrote: Hi Jerry, |
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Re: Estate sale scopes...
Rob
¿ªÔÆÌåÓýI figured it was Chinese USB scopes in the other place ? From: TekScopes@... [mailto:TekScopes@...] On Behalf Of Jim
Sent: Friday, October 26, 2012 8:33 PM To: TekScopes@... Subject: Re: [TekScopes] Re: Estate sale scopes... ? Well, the other place has Jetronic 545s .... ? Jim N6OTQ
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Re: Estate sale scopes...
Jim
Well, the other place has Jetronic 545s .... Jim N6OTQ
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Re: Estate sale scopes...
If Heaven don't have Tek scopes, I don't wanna gooooo!!!
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--- In TekScopes@..., Ron York <freelunch@...> wrote:
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Re: Screwdriver for Pozidriv (Pozi) Screws used by Tek
YES
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I work on cameras for a TV station. The screws are JCIS, but, the heads appear to be the same as JIS. The Phillips screw driver will not fit the JIS screw head without damage. Here is a link to some drivers. Here is a link to the specs. Here is a link to good technical data. Some examples More than you probably wanted to know. 73 Glenn WB4UIV At 04:12 AM 10/26/2012, you wrote:
Now that that's sorted, anyone willing to find out if there really is |
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Re: line voltage 7704a
Hi,
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I added about 3.1K of load to the HV drive and one power supply starts fairly well on the min-load. I have resistors coming that should increase the HV load to about 20w. It is only about 8 watts now i think. The power supply will not start at all in my 7704a. The wicked never rest. When the 7704A died my first indication of trouble was an unfocused line snaking thru the display. I shut it off and it never started again. I am suspecting an HV problem in the HV power supply now. More tomorrow. Jerry Massengale
-----Original Message----- From: Albert To: TekScopes Sent: Fri, Oct 26, 2012 3:54 pm Subject: [TekScopes] Re: line voltage 7704a
?
Hi Jerry,
Nothing helped to get rid of the oscillations when using my testload. True oscillation, about 12 MHz. So as a final attempt I also made sense lines connections, something I never did before. Against my expectation this cured the problem! There still is some switching noise in the rhythm of the inverter, but the DC voltages are fine now. This is the final configuration (|| means in parallel): +/-50V both 470R || 1k5, both 10uF to GND +/-15V both 22R || 22R, both 100uF to GND +5V 6R8 || 6R8, 100uF to GND +5VL 5R6 (to GND Lights, I did not connect pin 3 and pin 7). No other ground wires, except earth from chassis PS to chassis main frame to be on the safe side. All loads via the 10-pin LV connector and the 6-pin Sense connector. So nothing at the 54V lines for the HV supply. I didn't try it yet with less load, and I added the caps (values taken from the Main Interface Board) before I added the sense lines. So maybe these are not (all) needed. Anyway the result could be used as a guide I think. I used forced cooling; some resistors had to dissipate a little more power more than rated for. Albert > --- > I would expect the sense lines to be needed? They are directly connected on the interface. > Jerry Massengale |
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Fw: Question about JIS fasteners
Tom Jobe
Below is the first reply I got from a knowledgeable Honda friend.
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The link he included explains the thread pitch issues between the older JIS and the newer ISO thread standards. He doesn't believe there is a difference where the screw driver goes into the screw, between JIS and ISO. tom jobe... As far as the Honda thing goes, this is what i believe |
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Re: Screwdriver for Pozidriv (Pozi) Screws used by Tek
Jim
Wiha Tools also sells Pozidriv -- when this thread broke here, I googled Pozi, found their site, and bought some Pozi screwdrivers and some Pozi tips -- plus a whole bunch of Torx screwdrivers in sizes I didn't have. ?I will NOT mention how much I spent ... SWMBO might be watching ?:) ? even tho she doesn't keep a close eye on my toys, since she gets free fixit service on demand. Wiha has a much larger selection of Pozi than the fleabay vendor
mentioned, but priced 3x higher (or more) and shipping in the USA is about 3X higher too. ?But if you spend enough money, shipping's free (don't ask how I know) and if you spend more than that, sometimes they have a nice "freebie" tool whose price almost justifies the extra expenditure (don't ask how I know that either). Anyway, now I have a nice set of Torx screwdrivers and I need to make a nice holder for them out of a nice block of white oak I've been saving, on the floor drill press my brother-in-law gave me this week, and I also have a nice pair of linesman's pliers that'll probably outlive me. ?I'm very happy with the
quality f these Wiha pieces. ?The loose tips and the Torx screwdrivers are marked "Made in Germany" but the Pozi screwdrivers are unmarked as to origin, except for Wiha's HQ in Minnesooota. ?So if they're legally labeled, they were made in the good ol' USA. If not? ?Well, China already owns us so -- "same thing." Regardless, don't be ashamed of spending money on good tools. ?You'll almost always be really glad you did, even if it takes 20 years to realize it. 73 Jim N6OTQ
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Re: Screwdriver for Pozidriv (Pozi) Screws used by Tek
Rob
re. "~~and I absolutely have to know the truth or I will go crazy."
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With no myth/lie there is no truth and visa-versa..... Now you know... Hope this helped and is taken in the spirit intended.... Rob.....The Yin and the Yang... -----Original Message-----
From: TekScopes@... [mailto:TekScopes@...] On Behalf Of Stefan Trethan Sent: Friday, October 26, 2012 2:09 PM To: TekScopes@... Subject: Re: [TekScopes] Re: Screwdriver for Pozidriv (Pozi) Screws used by Tek I think there may be some grain of truth to it, as with any myth. But the problem is that there is an astounding amount of conflicting information, which usually doesn't happen if something is "real". They say any screw with a single dimple is JIS type. Now I must have seen hundreds of those screws in various kinds of equipment (for which I used a Phillips driver). So if these really are JIS then they are very common, say on the same level as torx. Yet none of the major manufacturers (like Apex, Wera, Snap-On, etc.) appears to have any suitable drivers or bits. How come if half the phillips screws really aren't Phillips nobody apart from a few small-time specialist suppliers carries them? It doesn't add up, it just doesn't. I don't care about motorcycles, but I've seen those screws with one dimple on electronic equipment many times and I absolutely have to know the truth or I will go crazy. ST On Fri, Oct 26, 2012 at 7:53 PM, Albert <aodiversen@...> wrote: I don't think it's a myth. You can read everywhere at www that Japanesemotorbikes use(d) JIS screws (it's also a thread standard) which need a special screwdriver. I also remember those bloody screws from my old Honda and Suzuki. (Now I only have old Brits with their own peculiarities.) I know a Honda dealer nearby who has been a well-known mechanic here for ages. He showed me a genuine screw driver for Honda workshops and a new or NOS screw. Definitively not Phillips or Pozidriv. It seems however that "JIS" didn't ring a bell. It might be a 4th type of screw head ...
------------------------------------ Yahoo! Groups Links |
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Re: Screwdriver for Pozidriv (Pozi) Screws used by Tek
Stefan Trethan
I've read in one place that the dimple denotes a metric Japanese screw, so that would be plausible.
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I still don't completely buy this story. If there is a different profile then why is the supply in the west limited to three small manufacturers, two of which are Japanese and specifically call their screwdrivers "phillips". Is it not much more likely that the better fitting drivers are just regular Phillips which happen to be better made and closer in tolerance? After shipping cost it's just out of the question for me to get a set and compare. Maybe I'll ask some of the German tool makers, I'm sure they have a screw nut or two sitting around. ST On Fri, Oct 26, 2012 at 11:39 PM, Tom Jobe <tomjobe@...> wrote:
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Re: Screwdriver for Pozidriv (Pozi) Screws used by Tek
Tom Jobe
¿ªÔÆÌåÓýI worked for Honda for many years, and the only difference
between flat head screws with and without the one dimple was the thread pitch on
some sizes of?fasteners as far as I ever knew. There was no difference in
the Phillips end of it that?I could tell.
For example, on a 4 mm screw the pitch used to be 0.75 mm and
in later years it was 0.70 mm, but?I don't remember which one had the
dimple.
I?never knew (or cared) which one was called JIS either,
but I did hear the JIS term mentioned.
Let me ask some of my older Honda friends about this, and I
will report back if I find out anything.
tom jobe...
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Re: Screwdriver for Pozidriv (Pozi) Screws used by Tek
When I worked at IBM, the manufacturing line used Posidrive screws due the the assembly robot's ability to pick up and hold the screw. The IBM Field Engineers were issued Posi screwdrivers made for us by Snap On.
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On one of my many trips to Japan, I purchased a new ham radio. I wanted to install some options in the radio before returning to the states. I stopped at a small hardware store and bought a set of VERY well made screwdrivers. The 'phillips' style were indeed JIS drivers. On our printer manufacturing lines at Lexmark, the techs used powered phillips drivers, but the screws in the different products (Canon, Minolta, Panasonic, etc) were JIS. My JIS drivers hold the Japanese screws much better. They actually hold the screws so well, it's like a strong magnetic bit. I have lots of the JIS screws, with Metric thread, of course..... ron N4UE -----Original Message----- From: Stefan Trethan To: TekScopes Sent: Fri, Oct 26, 2012 3:09 pm Subject: Re: [TekScopes] Re: Screwdriver for Pozidriv (Pozi) Screws used by Tek
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I think there may be some grain of truth to it, as with any myth.
But the problem is that there is an astounding amount of conflicting information, which usually doesn't happen if something is "real". They say any screw with a single dimple is JIS type. Now I must have seen hundreds of those screws in various kinds of equipment (for which I used a Phillips driver). So if these really are JIS then they are very common, say on the same level as torx. Yet none of the major manufacturers (like Apex, Wera, Snap-On, etc.) appears to have any suitable drivers or bits. How come if half the phillips screws really aren't Phillips nobody apart from a few small-time specialist suppliers carries them? It doesn't add up, it just doesn't. I don't care about motorcycles, but I've seen those screws with one dimple on electronic equipment many times and I absolutely have to know the truth or I will go crazy. ST On Fri, Oct 26, 2012 at 7:53 PM, Albert <aodiversen@...> wrote: > I don't think it's a myth. You can read everywhere at www that Japanese motorbikes use(d) JIS screws (it's also a thread standard) which need a special screwdriver. I also remember those bloody screws from my old Honda and Suzuki. (Now I only have old Brits with their own peculiarities.) I know a Honda dealer nearby who has been a well-known mechanic here for ages. He showed me a genuine screw driver for Honda workshops and a new or NOS screw. Definitively not Phillips or Pozidriv. It seems however that "JIS" didn't ring a bell. It might be a 4th type of screw head ... > > Albert > > On one of my many trips to Japan, I purchased a 's ability to pick up and hold them. The IBM Field Engineers were issued Posidrive screwdrivers mad by SnapO |
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Re: line voltage 7704a
Albert
Hi Jerry,
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Nothing helped to get rid of the oscillations when using my testload. True oscillation, about 12 MHz. So as a final attempt I also made sense lines connections, something I never did before. Against my expectation this cured the problem! There still is some switching noise in the rhythm of the inverter, but the DC voltages are fine now. This is the final configuration (|| means in parallel): +/-50V both 470R || 1k5, both 10uF to GND +/-15V both 22R || 22R, both 100uF to GND +5V 6R8 || 6R8, 100uF to GND +5VL 5R6 (to GND Lights, I did not connect pin 3 and pin 7). No other ground wires, except earth from chassis PS to chassis main frame to be on the safe side. All loads via the 10-pin LV connector and the 6-pin Sense connector. So nothing at the 54V lines for the HV supply. I didn't try it yet with less load, and I added the caps (values taken from the Main Interface Board) before I added the sense lines. So maybe these are not (all) needed. Anyway the result could be used as a guide I think. I used forced cooling; some resistors had to dissipate a little more power more than rated for. Albert --- |
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Re: Screwdriver for Pozidriv (Pozi) Screws used by Tek
Stefan Trethan
I think there may be some grain of truth to it, as with any myth.
toggle quoted message
Show quoted text
But the problem is that there is an astounding amount of conflicting information, which usually doesn't happen if something is "real". They say any screw with a single dimple is JIS type. Now I must have seen hundreds of those screws in various kinds of equipment (for which I used a Phillips driver). So if these really are JIS then they are very common, say on the same level as torx. Yet none of the major manufacturers (like Apex, Wera, Snap-On, etc.) appears to have any suitable drivers or bits. How come if half the phillips screws really aren't Phillips nobody apart from a few small-time specialist suppliers carries them? It doesn't add up, it just doesn't. I don't care about motorcycles, but I've seen those screws with one dimple on electronic equipment many times and I absolutely have to know the truth or I will go crazy. ST On Fri, Oct 26, 2012 at 7:53 PM, Albert <aodiversen@...> wrote:
I don't think it's a myth. You can read everywhere at www that Japanese motorbikes use(d) JIS screws (it's also a thread standard) which need a special screwdriver. I also remember those bloody screws from my old Honda and Suzuki. (Now I only have old Brits with their own peculiarities.) I know a Honda dealer nearby who has been a well-known mechanic here for ages. He showed me a genuine screw driver for Honda workshops and a new or NOS screw. Definitively not Phillips or Pozidriv. It seems however that "JIS" didn't ring a bell. It might be a 4th type of screw head ... |
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Re: 565 with 3a9 plugins on eBay- Kirkland WA
bob98033
I am the seller of the scope. This 565 along with two others to be listed later this week are from a lot purchased from University of Washington auction. Two years ago I purchased a similiar lot of four 565's from the University but these three are in much better condition and are marked on the front "keeper 2010". I suspect these will be the last 565's I will get because in the lot extra plugins and SPARE PARTS wre included. The list of spare parts include CRT's, timebase assemblies,high voltage transforer,etc basically everything you need to bring back a "dud" 565. After I checked,repair and verify calibration of the other two 565's I will put all the spare parts up for sale in lot, the extra plugins in another lot.
bob P.S. Anyone need 600 MHZ Tektronix pulse generator? I have one listed on ebay...It was part of the same lot along with a bunch of other Tektronix stuff to be sorted through. |
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Re: Screwdriver for Pozidriv (Pozi) Screws used by Tek
Albert
I don't think it's a myth. You can read everywhere at www that Japanese motorbikes use(d) JIS screws (it's also a thread standard) which need a special screwdriver. I also remember those bloody screws from my old Honda and Suzuki. (Now I only have old Brits with their own peculiarities.) I know a Honda dealer nearby who has been a well-known mechanic here for ages. He showed me a genuine screw driver for Honda workshops and a new or NOS screw. Definitively not Phillips or Pozidriv. It seems however that "JIS" didn't ring a bell. It might be a 4th type of screw head ...
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Albert I know that. Google them, They are available from US suppliers |
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Re: Tek 475 malfunction
¿ªÔÆÌåÓýThe Z axis is most likely ok.? Center up the position controls and
measure the DC voltage on each of the four deflection plates.
This is to see if it is an issue with the vertical or horizontal?amps
or the tube.
Report your findings.
?
Regards,
Tom
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David Hess
Michael Dunn
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