开云体育

YES! This one!

It youd be very fine, if you can do so.

reagrds
Ben

From: mailto:TekScopes@...
Sent: Sunday, November 30, 2014 2:06 PM
To: TekScopes@...
Subject: Re: [TekScopes] 3S3 Connectors


Is this the part you're looking for?



If so, I can read the part number from mine when I get home.

On Sun, Nov 30, 2014 at 3:38 AM, bene.dienst@... [TekScopes] <
TekScopes@...> wrote:

Hi Folks,
I have some troubles to find the connectors to attach my selfmade Sampling
Probe to the 3S3 Sampling probe unit. Tek has used Bendix Aeronautic
connectors with the typenumber 10-245330-4P on the plug in. Now I'm
searching for their counterparts.


regards
Ben

[Non-text portions of this message have been removed]

[Non-text portions of this message have been removed]

If you notice, that chip is a BGA, and as such has all sorts
of hidden solder joints. The little bouncy thing could be
there to flex those solder joints looking for a flaw... but
I kind of doubt it.

The funny part of that device is it appears to have a bunch
of touchy things that are arranged in a grid pattern. Maybe
there is some field sensing thing that can be done with the
ball grid array hidden joints?

I suppose one could cheat and go to the manufacturer's website
and see if they describe the machine's capabilities? ... NAH!

-Chuck Harris

Stefan Trethan stefan_trethan@... [TekScopes] wrote:

On Sun, Nov 30, 2014 at 6:09 PM, John Griessen john@...
[TekScopes] <TekScopes@...> wrote:

On 11/30/2014 10:34 AM, 'Mark Wendt (Contractor)' mark.wendt.ctr@... [TekScopes] wrote:

Then try our new ACME Super-Duper PCBoard Troubleshooter! ;-)

What is the hammer like pusher doing around 2:08 to 2:40?

My theory is it knocks on the IC to listen if the semiconductor holes
are empty or filled with electrons. ;-)

You can tell there are no normal people on this list.
We are looking at some crazy fast alien technology torture device with
pointy needles flying about and instead of stunned amazement all we
have to say is "what's it do there on top of that plastic".

ST

I kind of like spending a day at an electronics bench troubleshooting.

On 11/30/2014 10:34 AM, 'Mark Wendt (Contractor)' mark.wendt.ctr@... [TekScopes] wrote:

Then try our new ACME Super-Duper PCBoard Troubleshooter! ;-)

What is the hammer like pusher doing around 2:08 to 2:40?

Scary.

What does the round thing do at 2:20 bumping on top of that IC?

Just think of the poor guy who has to program all the limit values ;-)
(Actually I think they just self-learn from a known good board).


ST

On Sun, Nov 30, 2014 at 5:34 PM, 'Mark Wendt (Contractor)'
mark.wendt.ctr@... [TekScopes] <TekScopes@...>
wrote:

Then try our new ACME Super-Duper PCBoard Troubleshooter! ;-)

Is this the part you're looking for?



If so, I can read the part number from mine when I get home.

On Sun, Nov 30, 2014 at 3:38 AM, bene.dienst@... [TekScopes] <
TekScopes@...> wrote:

Hi Folks,
I have some troubles to find the connectors to attach my selfmade Sampling
Probe to the 3S3 Sampling probe unit. Tek has used Bendix Aeronautic
connectors with the typenumber 10-245330-4P on the plug in. Now I'm
searching for their counterparts.


regards
Ben

[Non-text portions of this message have been removed]

[Non-text portions of this message have been removed]

Thanks David, confirms our hypothesis.

John

Hi to All,

The XY Display Mode was standard on the older 7B50 and 7B70 Time Bases, With the newer 7B50A and 7B80 this was Option 02. You had to pay a little extra for this.

Greetings,

Egge Siert

Hi Folks,
I have some troubles to find the connectors to attach my selfmade Sampling Probe to the 3S3 Sampling probe unit. Tek has used Bendix Aeronautic connectors with the typenumber 10-245330-4P on the plug in. Now I'm searching for their counterparts.


regards
Ben

Hi David,
Yes the 7B80 Option 2 does exist. I have two of them.
They are not that hard to find and the XY capability is very nice to have.
Dennis Tillman W7PF

On 29 Nov 2014 14:32:45 -0800, you wrote:

It's generallly bad practice to add reactive impedance to the emitter of a common-emitter RF stage due to posative feedback via the collector-emitter capacitance.

Ferrite beads intended for use as snubbers are lossy having low Q at high
frequencies.

I've placed details in the files section. I'd still like to know if the Tek adaptors contain "special measures" !

They did. I have uploaded a photo showing the three ferrite beads included in
the 013-0128-00 adapter for the 7CT1N.

Hello,


This email message is a notification to let you know that
a file has been uploaded to the Files area of the TekScopes
group.


File : /Tek_curve_adaptor.pdf
Uploaded by : john_be_es <John@...>
Description : Dual transistor switchable adaptor for 7CT1N and similar curve tracers


You can access this file at the URL:



To learn more about file sharing for your group, please visit:



Regards,


john_be_es <John@...>

Thanks for all the feedback. As it transpires, I seem to have re-invented a couple of wheels! My adaptor is very similar to that described by Magnus.

Having spent part of my career taming class C rf devices, I'd already tried adding ferrite to the base drive, but this alone was not a complete solution. I've ended up with the following:

1. 22nF on the rear of the 7CT1N Emitter socket to the adjacent chassis ground.
2. Three beads on the Base lead of the adaptor
3. A multi-turn broad-band bead on the Collector lead in the adaptor.
(4. in case of RF FET testing, a switchable series R-C snubber Gate-Source) .

It's generallly bad practice to add reactive impedance to the emitter of a common-emitter RF stage due to posative feedback via the collector-emitter capacitance.

I've placed details in the files section. I'd still like to know if the Tek adaptors contain "special measures" !

John

So next I just hooked up a small DC fan to the supply to get something a little faster to experiment with. The strobe had no trouble at all, and I quickly could zoom in with the pulse generator settings to find it was running right around 3600 RPM - about 60 Hz for the rep-rate. At this speed, the flicker and eyeball effects are very small, and the image is bright enough to be useful even with lights on - the garage is well-lit with flourescent fixtures all over the ceiling, and there are more right over the bench, about three feet above the work surface. The picture labels note when the bench (overhead) lights are on or off - otherwise, only the ceiling lights are on.

The next two pictures show a good quality fan blade image readily obtained with 90 usec (about 2 degrees of rotation) pulses, even with the bench lights on - sufficient to find the speed, and look at image details. The next one, at 900 usec strobe width, shows the importance of the sampling width, and the tradeoff between image brightness and detail rendering. At 900 usec, it's ten times brighter, but also one-tenth the detail, with very fuzzy rendering. Even then, it's sufficient to check the RPM - it would probably be visible just fine in broad daylight. The last one of this group shows a closeup of the fan hub and blade at 90 usec - even the individual blade details can be seen, including dirt and lint (this one was in continuous service for years), and this detail can be improved at shorter sample widths, but with less brightness.

The next picture shows the simple ballast circuit - new technology meets old. Most of the ballast characteristic is from the incandescent lamps, shown here in lighting mode, carrying about 25 mA each. In strobe mode, they are cold. The big yellow thing above the lamps is the edge enhancement capacitor. The PTC to the right also affects the characteristic, but mostly is to protect the supply from any faults downstream.

So, how fast can it go? I didn't have anything handy that could spin a lot faster, so I decided to try oversampling the fan. Since there are seven blades, the next rep-rate that can provide a similar whole image is around 420 Hz, with proportionately shorter sample time of 12 usec. Sure enough, it lit it up just fine, although detail is limited because the image is actually seven different angle views superimposed. The next two pictures show the result. I also found that greatly widening the strobe had little effect on the fuzziness. Why didn't it mess up the image as in the 60 Hz test? Then I realized that widening back out to 90 usec was still only about two degrees of rotation at the actual speed, so oversampling with the original strobe width can get a brighter image yet. To properly render at the much higher direct speed, the strobe width would have to be narrowed down accordingly.

I tried even higher frequencies, and strobe effects were visible up to well over 1 kHz and down to 1 or 2 usec. This could be where the phosphor starts to crap out, or maybe my circuit, so I'm not sure beyond that range. However, 420 Hz represents direct strobe viewing at over 25,000 RPM - I think that's pretty impressive for this simple little thing. The next time I go to the farm, I'll try to remember to bring back a Dremel tool and a router to look at - those run pretty fast.

So, I still don't know whether a strobe will be any good for the winder, but now I'm convinced that a nice general pupose strobe can be readily designed and built using almost any high power white LED module as the light source. Besides frequency, the duty factor can be fully controlled, allowing for adapting to various conditions. The weak link is the unknown true peak current that may be attained. I also want to investigate the LED types used for camera flash applications - they should be optimized for very high peak currents, so maybe OK at lesser levels and higher rep-rates. If anyone knows the makers or part numbers of such LEDs, please let me know.

It's hard to beat the huge light output of a good ole xenon strobe tube, but the LED wins when it comes to resolution, control, simplicity, and safety. I have a nice old industrial type Xe strobe that needs rebuilding, but I may skip that project in favor of a making a whole new LED one.

That's about all I can say for now, but I'll have some more next time, and I'd like to talk about these amazing modern cameras too.

Ed

I couldn't seem to insert the picture here, so will upload to the original folder. It is called "redo 750 RPM, 12.5 Hz, 450 usec," and will be the tenth picture in the folder. After looking at it, I think the original two were OK after all, but now there's a definite one for comparison.

This is a case where the picture looks much nicer than the real thing - the camera tends to even out the lighting, making a fairly dim image look brighter. It also provides another degree of filtering (sampling) which gives a good still image, while the live image is drifting around, and it will never have an epileptic siezure no matter how long it looks at that damn flashing.

I'll do the upload now, and then continue the story.

Ed

There should be nine pictures in the "White LED strobe project" folder, showing various views and setups.

The two chuck pictures are of the winder running open-loop at about 750 RPM, depending on supply voltage, and not running, at 0 RPM*. I couldn't vary it much because the lighting circuit shares the base supply, and there's no motor drive circuits yet, and I didn't feel like getting out another supply to run the motor.

The winder will never need to run this fast, and the strobe had no problem at all keeping up. My eyeballs did have trouble though, because of the low rep-rate, and the drift in the motor speed and the setability of the generator. And this is at top speed - at lower speeds this will be even worse, so the strobe would be useless without being synchronized with the shaft rotation. I won't be able to tell how well it works until I get some of the strobe logic designed and built, and triggering from the shaft encoder. So, I decided to focus on operation at higher speeds, where strobes are normally used.

* On reviewing these two pictures, I began to think I may have gotten them mixed up, so they may be showing the same condition - they look too much alike. So, I just took some more shots at 750 RPM, 12.5 Hz, 450 usec, and all lights off, for comparison. It took quite a few shots to get a reasonably stable image while tweaking the speed, and trying to not to be affected by the flashing - I feel a little dizzy right now even, just remembering the activity from a half an hour ago. I'll end here for now, and I'll try to attach one of those shots to a separate post, or upload to the original folder if that doesn't work.

Ed

7B80 with option 2

They do exist, I have one!

Regards,
David Partridge

The 7B87 is specifically for the 7854 to allow viewing of waveform prior to
the trigger event when digitising in single shot mode.

It is like a 7B80 with the addition of the special single shot digitiser
support for the 7854

Regards,
David Partridge