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Hi Kurt,
thanks for these really interesting downloads.

Subject: [TekScopes] scanned: Tube aging and selection documents

The gems keep coming - thank you Kurt!

Craig

Subject: [TekScopes] scanned: Tek Transformers

Wow - that is a real find! Thanks for that!!

Craig

Leo;
What frequency range have you discovered with the "tunnel" diode that you chose?
Joe

On Mon, 16 Jul 2018 13:37:12 -0700, you wrote:

On Sun, Jul 15, 2018 at 08:45 AM, David Hess wrote:

They were using stories from actual science fiction writers. Larry
Niven wrote Inconsistent Moon which was episode 12 of season 2.

AAAAHHHH, I think I remember that one. the guy from Family Ties was on it and he was a scientist who figured the sun had gone nova, but it turned out to be a solar flare. He had the hots for this Woman and was a bit shy to approach her but when he thought the world was gong to end he went for her. She got a little bit miffed over that but got over it. the shockwave at the speed of sound hit them and the flare did kinda FUBAR the Earth but it did not kill everyone. he was kinda thinking when he wanted to cook all the food they had because the utilities were bound to go off.

There was a short story that this was based on, IIRC>

It had a bit more of a human touch than I prefer in scifi but not too bad. Even with Star Trek, which I cut my teeth on, the ones that are like a soap opera are not my favorite to say the least. I don't really even watch DS9 because of that. not that it is bad, it is just not my taste.

Berman. Piller. Sheer Evil.....

<never mind>

When I was a kid, 7 when it came out nobody was allowed to talk when it was on. We had the choice, shut up, outside or hell broke loose, maybe locked in a closet or something. My Parents were not really abusive at all. Tough, but then so was I. But the olman was allowed to talk and he made some jokes about it that literally had me on the floor rolling in laughter. I mean to the point where I missed part of the show. But they did reruns so all was not lost.

That series was great, as well as some that followed, but I have to say, the new Outer Limits actually beat them.

IIRC, even darker than the original. And the original? Very FEW
episodes were positive.... Not that I remember.

YMMV.

Harvey

On Mon, 16 Jul 2018 13:12:56 -0700, you wrote:

I've seen a standardization to several end destinations. One is that
the voltage rating seems to determine the size of the barrel
connector. That's now, from what I can see.

Secondly, there's a current limit that's also imposed. I have an HP
that wants higher current for the supply, and does not have the (older
standard) 5.5/2.1 (whichever *is* the "standard")) connector. It's
actually smaller in the barrel.

I'm going to conclude that there's an evolving standard out there, and
I have no idea of what it is.

Now, that is completely screwed up by the "DELL" standard, which
apparently includes some HP laptops.

Dell has a 3 wire cable to the power supply brick. The inner pin is
apparently an I2C connector. The inner and outer shells are power and
ground (suggest that the outer is ground). In a DELL computer, if the
power block does not identify itself as a "genuine" power adaptor,
then the battery will not charge.

Those adaptors (and don't ask me what I think of them) work with a
different standard. Not sure what the effective voltage and current
limits are in this case.

Bottom line, there *is* somewhat of a standard (don't know what it is)
that is now applied to barrel and pin diameters for different voltage
limits.

Harvey

They do seem to be approaching some modicum of standardization finally. My sister had 2 laptops different brands and the power supplies were interchangeable, and my Gateway supply runs them as well. They are all about 19 volts and it seems the polarity has been matching. I noticed an older Gateway adapter would not work on my newer Gateway and I suspect it is because it pulls more current. Maybe not running but it might charge faster. The diameter of the whole thing is the same but the pin in the middle is larger.

Right now I have the whole Toshiba motherboard for sale but you don't want it for just that. It works so I don't want to turn it into a parts mule. the older laptop is going to be my music server on the garage if I can ever get the wireless to work on it. you might look around for a laptop that has been dropped or something, you are not going to do mass production, right ?

Another idea might be a music store that sells electric, they likely also have effects pedals and many of them run of a wall wart. I worked at a music store like that for a bit and they had 2 boxes full of wall warts, one box of AC and one box of DC. they migth have some pedals that they can't fix. You can just try the plug, not even powering it up. The voltage doesn't matter, as long as it makes the connection.

Also for a one off (that's what engineers call them I think) you can just cut the wire and put on any connector you please.

This is hardly relevant, but it might be of interest to note that many TVS diodes exhibit negative resistance section.

I have made a proof-of concept oscillator that uses a TVS as an oscillator. Probably one of the simplest oscillators you can make.



Leo

On Tue, Jul 10, 2018 at 07:22 PM, Michael A. Terrell wrote:

That so called radio station looked like something from what 'Sanford & Son'
would have tossed out.

Yeah. It was a small town AM radio station with maybe 10,000 watts. What gets me is how he pushed microwaves through that tower that was clearly not built for it, and at a strength to reach pretty far into outer space. Oh, and no propagation delay either.

I like picking scifi apart like that. Some say I overanalyse but I say they underanalyse.

I've actually written a bit of scifi and it is not easy to create new futuristic science. I can't reveal it because of reasons, but I got good reviews on it. And then the timeline. I ran out of timeline. I had to go back and change things, pain in the (_|_).

I had a half decent science background, but many authors don't. The depend on research and whatever, themselves or assistants.

But all in all I think scifi is a good thing. I mean real scifi, not this magic bullshit like Harry Potter. I consider the pollution. But if kids watch real scifi it can stimulate their interest in real science. I can't say for sure if that happened to me but I think it likely.

My story ? A guy wakes up 396 years on the future. He is a kinky person and an engineer. After more contemporary education he is again and engineer and does well financially. He takes 2 Wives, and each give him 2 kids. And what brought him to the future had nothing to do with time travel, it was suspended animation. After 396 years they did figure out time travel.

i was like in another world when I was writing it. And I had to read what I wrote the day before to keep continuity. I know how difficult it can be to write really good scifi, and I don't consider what I wrote all that good. OK but not great.

If I bored you with this, sorry, but this is an off topic non political thread so I figure I have some license here.

Was this meant to be in the Tek Scopes list ?

Thanks for your input

I am using a short 50ohm bnc to bnc and it displays the correct wave on my other scopes. I just tried a second 2ft bnc to bnc and get the same result.

The attenuators such as c36 and c37 will not correct this much deviance. Nor will the compensation pots on the preamp. I have not tried much else.

But are you saying this could all be corrected with calibration? I am working on getting the correct hardware to calibrate but I wold like to get the square wave visually square, even if it is not calibrated. If there is still a issue, I believe there is, then I wont be able to calibrate until it is corrected.

On Sun, Jul 15, 2018 at 08:45 AM, David Hess wrote:

They were using stories from actual science fiction writers. Larry
Niven wrote Inconsistent Moon which was episode 12 of season 2.

AAAAHHHH, I think I remember that one. the guy from Family Ties was on it and he was a scientist who figured the sun had gone nova, but it turned out to be a solar flare. He had the hots for this Woman and was a bit shy to approach her but when he thought the world was gong to end he went for her. She got a little bit miffed over that but got over it. the shockwave at the speed of sound hit them and the flare did kinda FUBAR the Earth but it did not kill everyone. he was kinda thinking when he wanted to cook all the food they had because the utilities were bound to go off.

It had a bit more of a human touch than I prefer in scifi but not too bad. Even with Star Trek, which I cut my teeth on, the ones that are like a soap opera are not my favorite to say the least. I don't really even watch DS9 because of that. not that it is bad, it is just not my taste.

When I was a kid, 7 when it came out nobody was allowed to talk when it was on. We had the choice, shut up, outside or hell broke loose, maybe locked in a closet or something. My Parents were not really abusive at all. Tough, but then so was I. But the olman was allowed to talk and he made some jokes about it that literally had me on the floor rolling in laughter. I mean to the point where I missed part of the show. But they did reruns so all was not lost.

That series was great, as well as some that followed, but I have to say, the new Outer Limits actually beat them.

The land line is $60/month here now. Anyone recommend a system keypad, main system board with cellphone
function, and monitoring service that is low cost for the cell phone line charge and the monitoring?

Oh, and your post would not be considered off topic in TestgearNotTekscopes. A computer is definitely test gear. Actually so are amplifiers if you work on tuners, CD DVD players, tape decks. A tuner can be a source for a test signal if you are working on an amp. The only thing that is not acceptable there is Tek scopes because I do not want to divert any traffic from this group. It is just too nice.

And any home brew test gear is VERY welcome.

Just so you know.

They do seem to be approaching some modicum of standardization finally. My sister had 2 laptops different brands and the power supplies were interchangeable, and my Gateway supply runs them as well. They are all about 19 volts and it seems the polarity has been matching. I noticed an older Gateway adapter would not work on my newer Gateway and I suspect it is because it pulls more current. Maybe not running but it might charge faster. The diameter of the whole thing is the same but the pin in the middle is larger.

Right now I have the whole Toshiba motherboard for sale but you don't want it for just that. It works so I don't want to turn it into a parts mule. the older laptop is going to be my music server on the garage if I can ever get the wireless to work on it. you might look around for a laptop that has been dropped or something, you are not going to do mass production, right ?

Another idea might be a music store that sells electric, they likely also have effects pedals and many of them run of a wall wart. I worked at a music store like that for a bit and they had 2 boxes full of wall warts, one box of AC and one box of DC. they migth have some pedals that they can't fix. You can just try the plug, not even powering it up. The voltage doesn't matter, as long as it makes the connection.

Also for a one off (that's what engineers call them I think) you can just cut the wire and put on any connector you please.

On Mon, Jul 16, 2018 at 01:02 PM, Craig Cramb wrote:

I would say your probe is the causing this problem not the scope.

I would say the same thing. But after

"I have changed some of the attenuator settings and even tried adjusting the compensation from the preamp board but it has little effect."

I would think more work will need to be done.

I would say your probe is the causing this problem not the scope.

On Sun, Jul 15, 2018 at 04:52 PM, Raymond Domp Frank wrote:

Good luck!

If it is cyanoacrylate on nylon hell need it. I have never had luck gluing nylon. Even Plas-T-pair did nothing. If any glue works on it it seems like it works as a filler, Filling knurling or grooves or whatever and that is what makes it work at all. As far as actually bonding to nylon, I have never found anything that could do that and I have tried things. Not sure if I ever tried toluene but that is only a solvent like the Plas-T-pair, but they gave you some powdered resin with it.

I asked my Mother who is somewhat of an expert on such things because of her job, and she said there are glues that work well on nylon but they are expensive.

I hope it works out for the OPer, all I can say is use an ample amount, without spillage or over whatever and hope for the best. If it is not nylon then forget everything I just wrote...

On Mon, Jul 16, 2018 at 11:11 AM, Timothy wrote:

I am in the process of accumulating these devices and plan to learn to
calibrate my scopes. Although I know they wont be certified they at least will
be usable.

At the moment I have a 60mhz function/arbitrary wave generator. I am using
that for my square wave. I have other scopes that are putting the same square
wave up correctly.

What I used to set up my 465 was... PG506, assorted attenuators, 50ohm through termination, 20pf standardizer, 50ohm cables, the manual and surely I'm missing something. Everything done in order as laid in the manual.