On 12/21/23 20:10, Froggie the Gremlin wrote:

A novice tweaker can spend hours at first but after a few time you will get the "feel" of the controls.
The experienced pilot has it all in memory, the work becomes a pleasure...

Thanks Jon,
made me smile :-)

Raymond! Fine to hear from you,

The RT and BW on many TEK are conservative (unlike the Chinese scopes) and are often exceeded IF the test setup is optimized.

tips for optimized RT :

1/ Use direct connection , no cables , minimize adapters

2. Use high quality connectors eg BNC T, terminations, atten eg Mini Circuits HAT-20.

3. Use scope internal 50 Ohm term

4. Best pulser I found is Leo Bodnar 40 pS

5. Add 10..20 db 50 Ohm pad after gen to minimize back reflections and VSWR issues

6. Check many PU to see if aberration is in MFor PI.

7. Follow PU and MF align with NO extenders, eg remove scope side covers.

8. Be PATIENT, transient tweaking is NEVER perfect and is an INTEATIVE INTERACTIVE process.

9. The BW will "fall out" correclty IF the transient response is tweaked ......

A novice tweaker can spend hours at first but after a few time you will get the "feel" of the controls.
The experienced pilot has it all in memory, the work becomes a pleasure...

Hope to meet you in Netherlands sometimes 2024! \\

Amicalment,


Jon

Thanks for the explanation, Jon and yes, it's Raymond from the Netherlands.
My remark about the rise time: I see a rise time of 200ps in your photo, which is quite surprising, even for a 7104 with 7A29. It equates to around 1.75GHz bandwidth... I guess a direct-to-plate connection in a 7104 could provide that, but with internal amp and vertical plugin like a 7A29?

Raymond

John and Raymond (in Holland?)

to clarify:

1/ Scope shots are NOT 7104 /7A29
They are 7904/7A26

2/ Lower readout is delay time of B sweep of 7B92A hor plugin (excellent for all 7xxx except 7104)


3/ Risetime/aberrations....we have special needs to qualify high FS digital audio cables and transromers for low abberation and RT.

Our transformers are carrying up to 24.576 MHz Manchester coded AES/EBU, AES-3id and SP/DIF with FS to 192/384 thus half bit rate to 24.576 MHz and need at least 5th harm.
setup: Leo Bodnar 40 pS>>Mini ckts HAT-20 50 Ohm attn >>7A24 (or 7A29) 50 Ohm inoput

NO cables, direct connections.

Followed TEK serv on Vert plugin 7A24 and on Vert amp transient CAL.

As Chuck Harris once said, transient cal is more of an art than a science.

4/ The aberrations are all in the Leo B 10 MHz wave first few uS and slower Waves freq only reduces the trace intensity.

5/ Of course the plugin and Vert amp of the scope all contribute to RT and aberrations, so each channel of each PU and the Vert in the scope have separate CAL proceedures!


Enjoy,

Jon

On Thu, Dec 21, 2023 at 04:48 PM, Raymond Domp Frank wrote:

Come to think of it: The full character scan of the Readout module could perhaps benefit from a little adjustment: The "tails" are a bit short in the "n" and "p".
BTW, very nice edges! Did you check some slower edges too (say between 1ns and 10us), after this adjustment? In my experience, these often show some overshoot after adjusting the fastest edges, somehow.

Raymond

On Thu, Dec 21, 2023 at 04:14 PM, John Griessen wrote:

What is the lower right 00.79pS from? I see 10nS 200pS on top line and seem to be from the left right timebases.

I think that says 0.79ns. The 200ps rise time surprises me...

Raymond

On 12/21/23 00:14, Froggie the Gremlin wrote:

New photos:
/g/TekScopes2/album?id=291760
1/ 7104/7A29/7B10/7B15 with leo Bodnar 40 pS pulser after transient allignment

/g/TekScopes2/photo/291760/3725151
What is the lower right 00.79pS from? I see 10nS 200pS on top line and seem to be from the left right timebases.

My 7104s are not fully working at the moment...( I could not fiddle with same setup to figure it out).

New photos:

/g/TekScopes2/album?id=291760

1/ 7104/7A29/7B10/7B15 with leo Bodnar 40 pS pulser after transient allignment

2/ Bench with 7703/7L5, 7904, usual PUs

Many 7000 and TM500 PU on top shelf

Lots more !


Enjoy!

Jon

On Tue, Dec 19, 2023 at 08:31 PM, David C. Partridge wrote:

> What do you recommend using to clean switch contacts

?

For all the “finger” to pad cam switches, only ever use cartridge paper strips (say 1/8” by 1.5”) dampened with isopropyl alcohol.? Turn the cam so the finger lifts off the pad, insert the paper slip, turn the cam to drop the finger again, then slide the paper out.? Repeat as necessary.

?

David

Sounds exactly like the process I use to clean floppy drive heads on my vintage computers, just a tad more delicate.

- David

I'd agree with that 100%. When I've done it, I've just used regular
laser printer paper.

Paul

--
Paul Amaranth, GCIH | Manchester MI, USA
Aurora Group of Michigan, LLC | Security, Systems & Software
paul@... | Unix/Linux - We don't do windows

Had 7000 scoles and pluguns since 1990s, perhaps 4 scopes and 120 PU...
Fast notes:

Attn.contact clean :
Paper: We use business cards and 99% Iso Achol.

Beware some wideband PI like 7A29 use polysolfone substrate attn and need special cleaning precaution

7L5/12/13/18 All the TEK 7K SA have VERY difficult repair and service, and usually dead shaft encoder controls and sometimes burned out atten/mixers. Beware.

The sampling units are hard to use and finicky. Easier to just get a modern digital scope for plots, one shot, averaging.

The curve traced 7CT1 is rare and costly and hard to sue. Avoid unless a junker low cost.

Bon chance

Jon

On 12/19/23 20:40, Radu Bogdan Dicher wrote:

This is probably one of the most finicky restoration/maintenance tasks of any piece of equipment I am aware of. Not to discourage anyone, but it requires clean, careful and deliberate work.
Radu.
On Tue, Dec 19, 2023 at 6:31?PM David C. Partridge <david.partridge@... <mailto:david.partridge@...>> wrote:

> What do you recommend using to clean switch contacts

So, what IS cartridge paper?

"Quality cartridge paper will have a slight texture to it – this is known as grain or tooth, and provides the resistance needed to hold marks in place and increases the depth of range achievable in graphite or charcoal."

Art supply.

开云体育

I have a 7904.

One of my favorite combinations is a 7A26 (or 7A24 if I need the bandwidth), a 7D12 with sampling plugin, a 7D15 225 Mhz counter, and a 7B92A timebase.? The 7B92A does have a trace separation on the two traces.

An interesting use of the 7D12 is to use the A intensified by B function, take the B gate out, and run it to the trigger in on the 7D12.? It then samples the voltage on the intensified area of the race, allowing the equivalent of a cursor read.

Harvey

On Tue, Dec 19, 2023 at 03:13 PM, <Zentronics42@...> wrote:

EVERYTHING that I have gotten in to the lab in the 7K hardware has needed some kind of servicing. It could be as simple as cleaning the attenuator contacts to as complex as a full rebuild of the plugin followed by a calibration.

What do you recommend using to clean switch contacts that won't hurt the plastics? I know some contact cleaner sprays can soften some types of plastic.

The listed plugins 7a26, 7B70, and 7B71 are a good match for the frame though you might want to be on the lookout for a 7B53A(100Mhz Dual) or a 7B92 / A (500Mhz) the dual time bases will free up a Horz bay for another plugin. I was not a fan of the 7B7X plugins for the way they implemented the trigger control. Lots of plastic and when it cracks it is REALLY hard to get something working again. If you still want to run dual plugins kick up to the 7B80 and 7B81 . DO NOT grab a 7b87. The 7B87 is kind of a special time base for the 7854 to allow single shot capture.

?

I was originally going to order a 7B92 from the seller I got the scope from, but was told that while it will technically work in the 7704, the original 7704 does not have provisions to vertically separate timebases from the same plugin. Not really a huge deal, but that's the main reason I chose the 7B7x plugins instead of a dual timebase one. I might pick up a pair of the 7B80/81 plugins at some point in the future if I have problems with the 7B7x ones.

Thanks for the info, I'll keep the plugins you listed in mind!

开云体育

?On Tue, Dec 19, 2023 at 04:16 AM, Froggie the Gremlin wrote:

Bravo for the fine acquisition.

your location? Budget? Use of the scope/plugins? Budget?

Jon

I'm located in North Texas. I'm using the scope for hobby purposes, I don't necessarily have a specific application other than I'd like to have a nice variety of plugins. One of the reasons I was drawn to the 7000 series is that it offers a lot of functionality normally associated with more modern digital scopes, but with the interface and experience of using an analog one (no menus, loading times, or multi-function knobs). At this particular moment my 'most wanted' plugin is the 7D12, the sample and hold measurement function is one of the more useful looking functions I've seen on a plugin.

As far as budget goes, I'm not exactly sure. I was reluctant to buy them all off Ebay, as they typically are decently expensive and untested, I much prefer working with other hobbyists/enthusiasts.
Since I'm rather new to Tek stuff, I'm not sure what is considered 'fair'. In my experience collecting/trading vintage computer hardware Ebay tends to be a bit high. I'd like to not spend more than $100 per plugin, perhaps more depending on the plugin, its condition and if the plugin is tested.

On Tue, Dec 19, 2023 at 08:53 AM,?John Griessen wrote:

I have a collection of 7S11/7T11 Sampling Plugins, but have not gotten around to using them yet and want to
as a sampling learning exp, but then could sell them. How fast are you wanting them?

No big hurry, at this point I have all the plugins to use the scope in a normal way (4 channels, normal and delayed timebases), I'm just looking to eventually acquire some of the more interesting plugins. My primary application for the sampling plugins is assembling a setup with an X-Y chart recorder to record waveforms.

On 12/19/23 00:58, dkarguth wrote:

The following is my wishlist of plugins:

7S11/7T11 Sampling Plugins

I have a collection of 7S11/7T11 Sampling Plugins, but have not gotten around to using them yet and want to
as a sampling learning exp, but then could sell them. How fast are you wanting them?

--
John Griessen -- building lab gear for biologists
Albuquerque NM blog.kitmatic.com

Thanks for the education.