|
Re: Vector/Waveform Tek 1740A showing a ball instead of vector
TV shop grade colorbar generators used non standard frequencies to create
their bars. I once used a Heathkit IG28 at a TV station to transmit a color station ID over color bars at a monochrome station. It drove the master sync generator nuts, to genlock to the alien signals. On Thu, Sep 12, 2019 at 11:27 PM Alexandre Souza < alexandre.tabajara@gmail.com> wrote: Thanks a lot, Harvey! Spot On!
|
|
|
|
Re: Thermal Insulator question
Ed Breya
Why are you so worried about the voltage rating? How much voltage is on the case wrt the heat sink surface? Ed
|
|
|
|
Re: Thermal Insulator question
n4buq
Looks like you may have to wait on that?
toggle quoted messageShow quoted text
Thanks, Barry - N4BUQ
----- Original Message -----
From: "DW" <wilson2115@outlook.com>
|
|
|
|
Re: Thermal Insulator question
DW
https://www.digikey.com/product-detail/en/t-global-technology/L37-3F-150-150-0.45-1A/1168-1048-ND/3041877
I believe this is what I will go with. It has adhesive on one side so I don't have to worry about it falling off during servicing
|
|
|
|
Re: Thermal Insulator question
DW
While posting this material I decided to review the datasheet and found this is some advanced thermal material which is what I am not particularly concerned about which was mentioned not to be in my case, however it mentions a high dielectric strength of 17 kvAC/mm which is what I need. Maybe I should just keep looking.
This link demonstrates this thermal material https://www.digikey.com/api/videos/videoplayer/smallplayer/1668000939001
|
|
|
|
Re: Thermal Insulator question
DW
When searching for a thermal insulator I was assisted with a representative from Dijikey, since they had such a large variety of thermal insulators they helped me narrow down my choice with the details I gave them of needing high break down voltage and preferable material of silicone, rubber or fiberglass compounds. They suggested the following
https://www.digikey.com/products/en/fans-thermal-management/thermal-pads-sheets/218?k=p14965 They mentioned this material has a high breakdown voltage and you can get a big sheet of this for a decent price. Any thoughts? Maybe you just added something to your shopping cart?
|
|
|
|
Re: Vector/Waveform Tek 1740A showing a ball instead of vector
Harvey White
From the center out, the distance (not the direction) is proportional to the magnitude of the subcarrier. The angle of the vector/dot is the phase difference from the color burst. The little boxes show you where the appropriate values ought to be. What I think it wants to see is the color burst, and it can sync to that, since *everything* is relative to the burst phase, frequency, and amplitude.
toggle quoted messageShow quoted text
It's a neat way to see what colors are doing in the old NTSC system. Harvey
On 9/12/2019 11:26 PM, Alexandre Souza wrote:
Thanks a lot, Harvey! Spot On!
|
|
|
|
Re: How to change battery of Tek 2446 Scope
Alexandre Souza
Excellent advice, Greg. Thanks!
toggle quoted messageShow quoted text
BUT...Are there still soldering irons directly connected to the AC Line? Mine is an old WTCPN weller station, and it has a 24V transformer. So it is completely isolated from mains I have a switch on the earth wire of my soldering iron, so I can keep it connected to earth or completely isolated Thanks Alexandre ---8<---Corte aqui---8<--- http://www.tabajara-labs.blogspot.com http://www.tabalabs.com.br ---8<---Corte aqui---8<--- Em sex, 13 de set de 2019 às 13:52, Greg Muir via Groups.Io <big_sky_explorer=yahoo.com@groups.io> escreveu:
Although not really applicable in this instance, changing batteries in
|
|
|
|
Re: How to change battery of Tek 2446 Scope
Greg Muir
Although not really applicable in this instance, changing batteries in equipment where you must retain the saved data (cal factors, etc.) can be a bit tricky. There are a few methods and precautions that need to be followed lest you end up with the undesired results.
You can go in and replace the battery while the unit is under power but I prefer not to do that mainly because of any slips that might occur with the soldering iron causing damage to surrounding circuitry. Of great concern is going in with a soldering iron that is grounded to the third wire AC. Since the majority of equipment has its power supplies reference to the frame of the instrument and, hence the AC third wire ground, you will simply short out the supply voltage providing power to the memory that you are trying to save. Even if you float the soldering iron by use of a third wire ground “cheater” (those adapters that go between the AC plug and the outlet to which it is connected) depending upon the type of iron that you use (mostly the step-down transformer types) there may be enough stray capacitance within the iron circuitry to affect the battery supply circuit via transients and such when the tip makes contact. ESD may also have an effect since you have now removed the iron from AC ground. My method is to first disconnect the instrument from AC power then connect a bench supply with floating (not reference to 3rd wire AC ground) output adjusted to the battery voltage using around a 1k ohm resistor in series with the positive lead of the power supply. You could also use an external battery supply provided it is close to the range of the battery voltage that you are replacing. The leads of the power supply(/battery)/resistor are connected to the circuit of the target battery somewhere remote from the area where you will be removing it. The resistor will serve as a “soft” current supply to the battery circuitry so as not to inject high current into the non-rechargeable battery until it is removed yet allow a supply of voltage to the RAM while the battery is being replaced. Following the above procedure will allow you to keep your iron connected to the third wire ground and lower any chance of any ESD damage. But you must remember to first disconnect the instrument under repair from the AC supply to float it while you work. I use this method on all of my battery backed memory instruments and have excellent success. Of particular note is a model line of HP spectrum analyzers that actually have the battery backed RAM and associated battery contained on a small plug-in printed circuit board that can be removed for battery replacement. Otherwise it is usually a chore trying to get to the underside of a printed circuit board and having to do considerable disassembly to reach the trace pads for unsoldering/resoldering. The bottom line is to take your time and be very careful as to not short out the supply to the RAM while doing all of this or suffer the obvious consequences. Greg
|
|
|
|
Re: 100 Tek Photos
Vince Vielhaber
That's why a packing slip inside the box is important. Some of the fedex pouches (that thin clear envelope you stick on the package with the label inside) will rip open when slid across the floor of a truck and the label comes out. I had that happen to some of my outgoing packages a while back. Since then I've put a couple of strips of packing tape across the face of the pouch. With the packing slip or invoice inside, or at least a card with your address on it, the package will find its way back to you if not to the recipient.
toggle quoted messageShow quoted text
Vince.
On 09/12/2019 02:40 AM, nonIonizing EMF wrote:
On Wed, Sep 11, 2019 at 09:53 PM, Mlynch001 wrote:I just recently experienced my first lost in transit package with FedEx. Made it to Memphis TN and who know's? My guess was stolen like the other missing packages I've experienced before.
|
|
|
|
Excess scopes (7934, 7603, 468, 465)
Paul Amaranth
Clearing out excess equipment for a move. I don't want to ship
any of these at this time (two reasons: I hate shipping scopes and I don't have the time to pack them properly). You should be in driving range of SE Michigan (around Ann Arbor) or make a stop if you're on a fall color tour. I have a 7934 mainframe that is surplus to my needs. This one came out of a DOE facility and seems to work fine. No plugins, mainframe only $120. Also have a couple of 7603s with 1 V plugin + timebase $60 ea Also, a 468 mostly working + a 468 parts scope. $95 for both. I seem to recall some minor issue with that one, but it was a couple years ago and I have lost the details. Also, a couple of 465s; may be repairable, may be parts. No idea on these; I got them on a pallet. $50 ea Currently, these are all 80 miles away from me, so if you want pictures you'll have to be patient. Paul -- Paul Amaranth, GCIH | Manchester MI, USA Aurora Group of Michigan, LLC | Security, Systems & Software paul@AuroraGrp.Com | Unix & Windows
|
|
|
|
Re: Thermal Insulator question
DW
Good reply, thanks
|
|
|
|
Re: 100 Tek Photos
Dave,
I believe in there being more value in quality engineering, construction and materials than the latest whiz-bang blinking lights on things. I am going to completely wander off-topic, for a moment, but trust me - I'll bring it back. This is just to illustrate a point. (For context, I'm near 50 years old and am leaving it at that. :-P ) Think about your average washing machine from before, say the mid 1990s. Or refrigerators, TVs or many other items we used to take for granted that they would last for years. Now we have appliances - things that used to be called durable goods - that last maybe 7 years and end up in a landfill. I have to ask - which is worse for the environment? Having to wash your clothes twice in a new machine that doesn't get things as clean as a well designed one from the past that would get it done in one wash, but used a little more electricity and water; plus 3-4 of the new fangled ones ending up in the landfill compared to the life of an older one? How long do these LCD TVs last nowadays compared to the old Zeniths, RCAs, Sylvanias, etc.? Back to the point about Tektronix - as the mind-set of the world went away from designing quality equipment that stands the test of time to the notion of "everything has the shelf life of a banana," unfortunately a company culture built on the principles of design, quality and workmanship is going to struggle in the planned obsolescence / disposable world. It is an ongoing struggle for Tektronix, IBM, General Electric, Altec Lansing, Western Electric, RCA, Maytag and countless other companies in the United States, Germany and other nations known for the products they (once?) produced. Many of these companies are shadows of their former selves because the world has become distracted by "the new thing of the week," and has largely given up on quality. So to your point Dave, in this day and age of a disposable TV that you purchased for $99 on sale that would cost more to repair than pitching it in the landfill and getting a new one, how much test equipment do the technicians even need? And another question that raises.. how many technicians even are there anymore? How many millennials out there would know how to so much as change a tire, fix an outlet or light-switch in their home, replace a bulging motor-run cap on their air conditioner or the like? But they can sure set up Wifi and ask Alexa to do their shopping. The worst part of it to me is that we get extra features that don't matter and with it, planned obsolescence. This is why this group is valuable - It is not just for pure nostalgia that we are enthusiasts for this equipment. Today so much of it is as viable as modern equipment (if maybe not as convenient in some regards and certainly not as energy efficient) for so many tasks today, and in many cases superior to a lot of modern equipment depending on the task. This is a testimony to the minds, vision, effort, and pride the folks who started and made Tektronix Tektronix. Seeing where and to some extent how they built these products in pictures was a treat! Best regards, Jason
|
|
|
|
Re: How to change battery of Tek 2446 Scope
tekscopegroup@...
The 2245, 2246, 2247A and 2252 scopes only store front panel configuration in volatile memory so the scope will power up exactly as you left it before power down. There are no calibration constants being backed up by the battery. A typical symptom of a battery that requires replacement is that the scope will always power up in a default configuration, and any settings prior to power off will be lost.
The battery is a 3V 1200mAh 2/3-A size cell like the Panasonic BR-23AE5SP. It needs to have one solder tab on each end (with only one prong). There are versions that have one prong on one side and two on the other so the battery cannot be installed in reverse. Not the case in these scopes. If you get the 3 prong version you can still use it by just trimming off the two pronged side and solder a stiff wire in place.
|
|
|
|
Re: How to change battery of Tek 2446 Scope
Bob Koller <testtech@...>
I think you mean a 2246 scope? If so, the battery on this series of scope doesn't maintain any non-replaceable cal data. Simply run the front panel user cal as found in the manual. No equipment required.
|
|
|
|
Re: 100 Tek Photos
Chuck,
Thank you! There is rarely one of your posts from which I do not gain an insight on a wide range of subjects. -- Michael Lynch Dardanelle, AR
|
|
|
|
Re: 100 Tek Photos
Amen to your rule, Dave! I have had very similar experiences in my life as well.
|
|
|
|
Re: 100 Tek Photos
ArtekManuals <manuals@...>
Been there .... done that . At the age of 55 my father built his last boat of many...(a 50' fero-cement (concrete) Ketch). The diesel auxiliary engine for it was a scavenged one that purportedly started life as the engine from a double decker tour bus. By the time I was 12 I had my own TV repair business and for the next 25 years my father never owned a TV ( or computer) that wasn't a trash rescue that I resurrected for him. At age 65 his VCR died it took him 6 months of checking out books at the public library but he finally fixed it by himself ( he was a structural engineer ....not a EE). RIP Dad, he passed away last year at 98 . I am 72 and have only owned one new car car in my life. The truck I had before the one I have now went 215,000 miles before I sold it too a friend of mine for $500 and 1/4 of a deer 8^) .....You get the idea 8^)
toggle quoted messageShow quoted text
And the current generation looks at us like we are nuts when we raise our eyebrows when they buy EVERYTHING on installment ...sigh Dave manuals@artekmanuals.com
On 9/13/2019 9:58 AM, Chuck Harris wrote:
This is possibly getting out of hand. I didn't say anything --
Dave Manuals@ArtekManuals.com www.ArtekManuals.com
|
|
|
|
Re: Thermal Insulator question
Chuck Harris
The originals were likely mica, or a silicone rubber/fiberglass
toggle quoted messageShow quoted text
composite. I would choose a silicone rubber fiberglass composite. There is a high voltage isolation need here, and only a minimal thermal transfer need... so avoid stuff meant for the CPU race-rod crowd. -Chuck Harris DW wrote:
I am looking at fixing the thermal pad insulator situation with the Tek 577 but I noticed there is so many kinds of thermal pads to choose from, what would be a good choice? Thanks
|
|
|
|
Re: 100 Tek Photos
Chuck Harris
This is possibly getting out of hand. I didn't say anything
toggle quoted messageShow quoted text
was wrong with tek building things on the cheap, I made an observation that tek built their office furniture on the cheap. I happen to recognize what they did, because I was raised in that Great Depression mentality. As I said, I was 7 or 8 before I sat, ate, studied, played, or ??? on/in something that wasn't built by hand, by my dad. My dad even built our TV (not a heathkit), the violin he played, and fixed and repaired the cars he drove, and the watches he wore. We even built our own camp, and I helped clear the trees, dig the well, and I dug the outhouse. And my mom was the flip side of the coin... she made my meals, clothes, costumes, tents, rucksacks, the pictures that hung on the walls, root beer, bread, butter, mayonnaise, peanut butter, and magically turned butter back into cream.... It has everything to do with why I am the way that I am. The reason this observation was interesting to me is it was proof positive that tektronix believed that if it wasn't done by tektronix people, it was bad for some reason.... if it fits my pattern, usually that reason was economics. Look at how the company naturally vertically integrated itself: They made scopes, crt's, terminal boards, hybrids, IC's, sockets, transformers, capacitors, resistors, nuts and bolts, cabinets on scopes, plastic injection molding, cam switches, shafts, ... all the way down to manuals, binding, desks, carrels (cubicals), calendars, ... and as we learned lately, even shipping peanuts.... And look at their catalog. Ever wonder why they did such a diverse, and somewhat quirky selection of instruments? Think about self need: Make CRT's need light meters to test beam intensity. Make manuals, need printers to print manuals, plotters to plot schematics... Make PCB's, IC's and hybrids, need graphics, layout equipment, bed of nails, signature analysis, data collection, wire bonders, and automated probing stations... Ultimately, what breaks such a company's back, is the same thing that broke mine: you can't be good at everything, and still compete economically. A lot of tektronix's special talents looked cheap to do, when you were raised up in that Great Depression mindset, but cost the company its soul, when the US government was no longer there to foot the bill. I admire tek greatly for what they did, but still, in my heart of hearts, I am super glad that I was too afraid of rejection to apply there after college. They would have hired me, and I would have fit right in. -Chuck Harris Dave Seiter wrote:
I don't think there is anything wrong "building things on the cheap" as long as they work and are safe. I've seen so many offices where they spent stupid sums of money on furnishings to impress people. That sort of thing doesn't impress me- I think it's wasteful.
|
|
|
