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On 11/30/18 1:57 PM, David Slipper wrote:

I seem to remember someone talking about plug-in extenders - were they
for the 7000 series ??
If so are they still available ?

There are mine that use 24 gauge single wires but I just ran out of custom connectors,
so that needs a waiting list again, or maybe it's time is up...

Then there are some extenders by Dan Meeks sold on amazon that have less assembly labor and are for TM500 I think.

I seem to remember someone talking about plug-in extenders - were they
for the 7000 series ??

If so are they still available ?

Dave

Is there anyone here intimately familiar with the internal workings of the 7T11 plugin? I ask because I'm trying to get one to work. The symptoms are that there's no trace visible on the screen.

I had it on an extender in the bench today and established that most of it is working: the trigger circuitry, strobe pulse generator and slow scan all seem to be doing what they should. However:
- the trace is blanked because the X/sweep output is out of range (it's at about +15V)
- it seems to be out of range because the horizontal memory isn't getting any strobe pulses
- the holdoff multivibrator, which generates said pulses, looks like it's working
- there's a peculiar arrangement of resistors, a diode and a 100pF capacitor which takes the outputs of the multivibrator (a 7400 chip) and is supposed to switch on a PNP transistor (Q546 I think) which has its emitter tied to ground (in equivalent time sampling mode). This is not happening. The transistor's base never goes below ground so it never switches on.

Looking at the circuit diagram, I can't see how it's supposed to work. I don't have the manual in front of me right now but does anyone know this part of the circuit well? My next move is likely to be replacing the 7400 to see if a different one somehow magics it in to operation.

Thanks
Chris

Just a thought...

It doesn't have to be a huge voltage, if it's at a high frequency. That 300 V RMS probably applies only to low frequency signals. The maximum allowable voltage is usually derated with frequency. I have damaged a probe by looking at moderate level signal levels (well within the low frequency rating of the probe) at 30 MHz.

Gary Appel

Thank you, John, for the mention.

For anyone looking for replacement scope feet, I would also add that I can supply them for a number of different scopes. They're available both on eBay and at a slightly lower price on my website, www.n0dy.com<>.

I have feet for:

* 465/475/463/466/468 (rear cord wrap)
* 453/454 (rear cord wrap)
* 453/454/465/475/463/466/468 (bottom)
* 314/335 (rear cord wrap - the ones mentioned)
* 106/114/115/184/191 series signal generator rear feet
* 7000 series rear cord wraps
* 7000 series bottom
* 5000 series bottom

Plus some odds and ends.

Regards,
Jeff N0DY

________________________________
From: [email protected] <[email protected]> on behalf of John Clark <johnclark05@...>
Sent: Friday, November 30, 2018 9:10 AM
To: [email protected]
Subject: Re: [TekScopes] Back feet for 335 scope

These feet are also now available on eBay:



<>John

________________________________
From: [email protected] <[email protected]> on behalf of sp856567@... <sp856567@...>
Sent: Friday, November 30, 2018 4:29 AM
To: [email protected]
Subject: Re: [TekScopes] Back feet for 335 scope

There is a young mechanical engineer here in the Netherland who have drawn in 3D and printed for me 3 sets (3 x4 ) of the 335 back feet for me. I still have 2 sets left. Price is €12.60 for the set off 4 + €1.40 shipping cost ( as normal letter not registerd ). total € 14,00 which are about $12.30
For fotos and information contact me at: sp856567@...

It is unlikely you will ever know what they did... unless you pull the
attenuator out, remove its covers, and look for yourself.
Pretty easy work with any stereo dissection microscope.

That is what I've done and how I found the defective parts and fixed it.
The link to the Tek forum with pictures was in my opening post.


There is no further damage visible...
But damaged components are not always visibly damaged.
And that was the reason why I asked for the schematic.

To blow that resistor, your friend must have over voltaged
that input quite a lot. It probably involved the power line.

Yes is seems that it had a huge voltage because the scope is
specified for 300VRMS on the input.

But it seems there are no schematics available to do a good analysis on this circuit.

I will put it back together and use it again. Quite a shame that
documentation is not available any more these days...

Thanks anyway...

These feet are also now available on eBay:



<>John

________________________________
From: [email protected] <[email protected]> on behalf of sp856567@... <sp856567@...>
Sent: Friday, November 30, 2018 4:29 AM
To: [email protected]
Subject: Re: [TekScopes] Back feet for 335 scope

There is a young mechanical engineer here in the Netherland who have drawn in 3D and printed for me 3 sets (3 x4 ) of the 335 back feet for me. I still have 2 sets left. Price is €12.60 for the set off 4 + €1.40 shipping cost ( as normal letter not registerd ). total € 14,00 which are about $12.30
For fotos and information contact me at: sp856567@...

Didn't know that € felt down below USD...

No.

The Ballantine 6125a Oscilloscope Calibrator .pdf on BAMA is a different and older architecture.

The 6125a does not incorporate the Tek SG503 nor Tek DM501 modules in the Ballantine 6 slot mainframe ( likely a Tek TM506 ?? ) with the
Ballantine 6126M module + Ballantine xxxx "Time/Div." module (part# unknown). Check photos of the 6125a Vs. the 6126M photo inn the web link that Bob sent in the 1st reply to this topic, above.

So, the Ballantine 6126M in the mainframe unit appears to be a different animal.

Thus, -- am still looking for .pdf manuals for the Ballantine 6126M Calibrator & its companion Time/Div. module !!

thanks,

How much do you ask for your 2465B (should be sent to Amsterdam Netherland?
My email: sp856567@...

I have let Tek 335 back feet to be printed and have extra 2 sets (4 each set - one foot of the 8 is orange color !). Price is €14 per set of 4 feet + €2 for shipment as regular letter to all over the world ). Registered shipment possible at cost of €15-€17( depends on country).
For more information and fotos mail to:
Yoram Stein
sp856567@...

There is a young mechanical engineer here in the Netherland who have drawn in 3D and printed for me 3 sets (3 x4 ) of the 335 back feet for me. I still have 2 sets left. Price is €12.60 for the set off 4 + €1.40 shipping cost ( as normal letter not registerd ). total € 14,00 which are about $12.30
For fotos and information contact me at: sp856567@...

Stainless Steel can be pre-tinned with acid flux and either a large iron, or a solder pot.


Michael A. Terrell

Thanks to everyone for all the assistance on the scope clock. I received an email back this evening that parts had come in and he needed my PayPal ID so he could send me a PayPal invoice. I know it's a bit of a novelty but for someone who owns a real nice 475, but who doesn't use it very often, it will give me a reason to turn it on in my den/office when company is around.

John
________________________________
From: [email protected] <[email protected]> on behalf of johnasolecki@... <johnasolecki@...>
Sent: Thursday, November 29, 2018 9:23 AM
To: [email protected]
Subject: Re: [TekScopes] AVR Scope Clock

I just received one of his clocks several weeks ago, I had to keep checking back as he seems to run out quickly. It appears to have more functions than any other one I looked at.

John

On Thu, 29 Nov 2018 19:38:13 +0100, you wrote:

BTW you can get the standard ground lead with the probe side spring
and crappy alligator clip on Digikey for $2.65:
<>

Thanks, since I'm not using the alligator clip, I don't care about the
quality of the clip.

The one with the marginally less crappy alligator clip can be had for $10:
<>

Ouchie....

BTW: you *can* buy clips that look identical from McMaster-carr.
Problem is that they are not copper, they're 18-8 stainless or zinc
plated steel. Not sure that I want to try soldering to them.

This is assuming that the clips can be had in the right size.

Harvey

ST
On Thu, Nov 29, 2018 at 7:20 PM stefan_trethan <stefan_trethan@...> wrote:

Harvey,

I have found that for me the most practical solution is to use BNC
adapters and directly solder to the BNC end.
Yes, this means you also need to make the center connection in that
manner, but that is really more practical anyway.

I have about 2 inches of silicone or teflon wire soldered to the BNC
end (red/black) and a 0.025 square single connector.
The square connectors plug into pins soldered on the PCB, or more
often into Hirschmann micro Kleps:
<>

I also have a set of these BNC adapters with just wires connected to
them, which I can solder directly to boards (and leave connected for a
while).
The BNC adapter body is protected with a section of silicone tubing to
prevent shorts to ground.
It looks similar to this part from Lecroy (PMK):
<>

I haven't used a probe to poke on something directly for probably
years, and haven't used a "witch hat" hook tip for even longer.
They really aren't very practical for my line of work.

There is an impact on signal fidelity of course, but often times I bet
I have it better than a regular ground clip lead, and if needed I also
have sockets I can solder on a PCB to stick a probe in directly.

ST




On Thu, Nov 29, 2018 at 6:48 PM Harvey White <madyn@...> wrote:

I'm going to build a number of ground clips for the P6100 series
probes that terminate in a 0.025 square connector.

I have those connectors, but I don't have a good source of the clips
for the scope probe body.

A good example of the probe would be a P6105. I'd also like to see if
there's an inexpensive source of the slip on 0.025 probe tip adaptors
as well, although those might be a 3D print option.

It does occur to me that I may be able to make a whole probe slip-on
adaptor that bypasses the need for the ground clip, but I'd like to
see if I can do the standard ground clips.

Harvey

BAMA has one for the 6125a, not close enough ?

On Thu, 29 Nov 2018 19:19:49 +0100, you wrote:

Harvey,

I have found that for me the most practical solution is to use BNC
adapters and directly solder to the BNC end.
Yes, this means you also need to make the center connection in that
manner, but that is really more practical anyway.

I'll have to think about that, don't have any of them, either. (maybe
one or two that came with a 7A11?)

I have about 2 inches of silicone or teflon wire soldered to the BNC
end (red/black) and a 0.025 square single connector.
The square connectors plug into pins soldered on the PCB, or more
often into Hirschmann micro Kleps:
<>

I have a half ton of 0.025 pin connectors. I use 20 pin adaptors to
the HP 16702B, otherwise, they can be test points.

I also have a set of these BNC adapters with just wires connected to
them, which I can solder directly to boards (and leave connected for a
while).

The way those things go, I'd be breaking wires. The boards move
around a lot in development.

The BNC adapter body is protected with a section of silicone tubing to
prevent shorts to ground.
It looks similar to this part from Lecroy (PMK):
<>

That was my option for a complete slip-on adaptor.

I haven't used a probe to poke on something directly for probably
years, and haven't used a "witch hat" hook tip for even longer.
They really aren't very practical for my line of work.

Depends on what I'm looking at. In normal scope repairs, I normally
will use a dip-clip or the hook adaptor for discrete parts. For my
own SMT projects, I have to design in the test points (frequently).

There is an impact on signal fidelity of course, but often times I bet
I have it better than a regular ground clip lead, and if needed I also
have sockets I can solder on a PCB to stick a probe in directly.

Similar to what I do with the logic pods.

So is the center pin in a BNC the same size as the probe tip in the
probe? That would be convenient.

Just checked, the probe tip appears smaller.

I see something happening with the 3D printer, maybe.....

Thanks

Harvey

ST




On Thu, Nov 29, 2018 at 6:48 PM Harvey White <madyn@...> wrote:

I'm going to build a number of ground clips for the P6100 series
probes that terminate in a 0.025 square connector.

I have those connectors, but I don't have a good source of the clips
for the scope probe body.

A good example of the probe would be a P6105. I'd also like to see if
there's an inexpensive source of the slip on 0.025 probe tip adaptors
as well, although those might be a 3D print option.

It does occur to me that I may be able to make a whole probe slip-on
adaptor that bypasses the need for the ground clip, but I'd like to
see if I can do the standard ground clips.

Harvey

BTW you can get the standard ground lead with the probe side spring
and crappy alligator clip on Digikey for $2.65:
<>

The one with the marginally less crappy alligator clip can be had for $10:
<>


ST

Harvey,

I have found that for me the most practical solution is to use BNC
adapters and directly solder to the BNC end.
Yes, this means you also need to make the center connection in that
manner, but that is really more practical anyway.

I have about 2 inches of silicone or teflon wire soldered to the BNC
end (red/black) and a 0.025 square single connector.
The square connectors plug into pins soldered on the PCB, or more
often into Hirschmann micro Kleps:
<>

I also have a set of these BNC adapters with just wires connected to
them, which I can solder directly to boards (and leave connected for a
while).
The BNC adapter body is protected with a section of silicone tubing to
prevent shorts to ground.
It looks similar to this part from Lecroy (PMK):
<>

I haven't used a probe to poke on something directly for probably
years, and haven't used a "witch hat" hook tip for even longer.
They really aren't very practical for my line of work.

There is an impact on signal fidelity of course, but often times I bet
I have it better than a regular ground clip lead, and if needed I also
have sockets I can solder on a PCB to stick a probe in directly.

ST

I'm going to build a number of ground clips for the P6100 series
probes that terminate in a 0.025 square connector.

I have those connectors, but I don't have a good source of the clips
for the scope probe body.

A good example of the probe would be a P6105. I'd also like to see if
there's an inexpensive source of the slip on 0.025 probe tip adaptors
as well, although those might be a 3D print option.

It does occur to me that I may be able to make a whole probe slip-on
adaptor that bypasses the need for the ground clip, but I'd like to
see if I can do the standard ground clips.

Harvey