As I recall, they both taste the same...

-Chuck Harris


On Fri, 12 Apr 2024 12:00:06 -0700 "Tom Lee" <tomlee@...>
wrote:

Intermediate Power Amplifier (as opposed to a Final PA).

Or maybe India Pale Ale. One never really knows...

Tom

We settled on Tektronix P6137 10x, P6136 Zo 50Ohm for our 2465/7B, 7904 and 50 ohm vert plugins

The HP, and others can't be compared to genuine Tektronix

Yokogawa are a close second

We normally use a fast rise edge not BW or network analysis to check probes as transient response, abberation and rise times are closer to our work.

The Tektronix PG506A cal Gen has a fast rise.

The Leo Bodnar 40 ps BNC pulser is one of the best.

See Tektronix circuits concepts books for probe circuits and measurements.

Enjoy

Jon

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That could be the difference, none of the mains powered ones I've seen have a line fuse anywhere, but there is space to fit a fuse holder inside mine.

I've started scanning the manual.

David

Maybe this is why chem labs don't want you to keep your brews in the lab.

Intermediate Power Amplifier (as opposed to a Final PA).

Or maybe India Pale Ale. One never really knows...

Tom

--
Prof. Thomas H. Lee
Allen Ctr., Rm. 205
420 Via Palou Mall
Stanford University
Stanford, CA 94305-4070

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Forgot to add the pictures, in case it helps someone in the future.

?

?

?

Update:

Repair is coming along just fine.

I used a vinegar bath with a scrub brush in the kitchen sink, followed by a rinse, then some baking soda and water, then another rinse, then some Dawn dishwashing soap and a final rinse.? After that, I popped it into the oven at 170 degrees for a couple of hours.? It all turned out nicely.

I was wrong about it being a 3-layer board.? It's actually 4-layer.? It appears all the inside layers were protected well by the vias and the solder.? A continuity check revealed all to be as it should in the area.

The connector came out uneventfully with a manual piston-style solder-sucker (SOLDAPULLT-III - my favorite!) with about 20 minutes worth of work.

I noticed that this isn't the first connector to be replaced on this unit (red arrow).? It had problems in the past with the connector for the A11 Second LO board.

Waiting on the connector, and the power supply card from Daniel.

Glancing at the calibration procedure for this... it looks like I'll be busy that day!

Incidentally, does anyone have the schematics for all versions of the A80 board?? I've got what I thought was all the service manuals available for this, from Keysight's web site and from KO4BB's site, but in no place do I see the A80 board schematic.? All I could find is a blurb about a few different revisions of the board, and one major change to a different style in the later versions.

?

I think Matt you left out Beryllium Oxide dust from RF devices in that
lot;)...

I still have a half-dozen solid state IPAs with the BeO2 scull & crossbones on them.? Oddly enough, I was never dumb enough to take an angle grinder to a ceramic vacuum tube... I don't even know why someone would need to do such a thing even if it did not have BeO2 lurking inside, ready to cause a slow, lingering death.

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What language to do you speak?

Alguns SMPSs têm um limite absoluto em sua saída de corrente mínima. Eles só s?o capazes de produzir acima de um certo nível de potência e n?o podem funcionar abaixo desse ponto. Em uma condi??o sem carga, a frequência do circuito de fatiamento de energia aumenta a grande velocidade, fazendo com que o transformador isolado atue como uma bobina de Tesla, causando danos devido aos picos de energia de alta tens?o resultantes. As fontes comutadas com circuitos de prote??o podem ligar brevemente, mas depois desligar quando nenhuma carga for detectada. Uma carga fictícia de baixa potência muito pequena, como um resistor de potência de cer?mica ou uma l?mpada de 10 watts, pode ser conectada à fonte para permitir que ela funcione sem carga primária conectada.

On Fri, Apr 12, 2024 at 03:34 PM, jmr wrote:

I do have access to a Tek P6139A if I can find it.

A P6139A would be a good candidate as well. It's slightly older than the P6139B but has very similar behavior, AFAIK.

Maybe I could at some stage compare both, perhaps include an HP 10441A. I have adapters/extensions, appropriate generator/scope and VNA. I'll need to find the time.

Raymond

anything?

Hi Raymond, I don't have any of those probe models here. I do have access to a Tek P6139A if I can find it. It's the probe that came with my Tek scope.
Note that in the rise-time tests of the probes I set my scope to 1GHz bandwidth to make sure the scope wasn't limiting things. I don't own a Tek 2465A so I can't test in the same way as Jinxie.

Regards
Jeremy

Switching power supplies can not work without enough load.

They go into a cycle where they turn on, and then off.

You need to connect a resistor to their big output that will

load the supply to 1/10th its rated current or more.

-Chuck Harris


On Fri, 12 Apr 2024 03:08:30 -0700 "Jesse Joabe"
<jessejoabe2007@...> wrote:

Sorry. I use translator. I couldn't understand the words and the
concept. Sorry. But I appreciate the help

JMR,
Thanks for sharing all your knowledge and expertise.
With regard to your comparison between four probes, I am wondering if you could do or know about another, less apples-to-oranges comparison, than the HF-targeted 10073A/C on the one side, and the Tek P2020, a LF-targeted (by Tek's description) 200MHz / 17pF 1MOhm / 10MOhm 1x / 10x *switchable* Tek probe plus an unbranded probe on the other.

I'd be interested in a comparison between (one of) the two 10073's, and something like a Tektronix P5050B / P6139B 500MHz / 8pF Hi-Z probe, or a LeCroy /Pico 500MHz TA133 (9.5pF), PP006 (12pF) or the like or even an appropriately adjusted Tek P6137. I'm sure you know that the P5050B's 'scope compensation range? is more targeted at HF use, with its lower-cap. adjustment range than the P6139B, and the P6137 comes adjusted especially for Tek 24xx 'scopes.

Appropriate conversion sleeves from probe tip to BNC are available for all.

Raymond

You must be thinking of the vintage scope probes from 40-50 years ago. These were huge things that had a fat tip pin that could interface directly with a BNC connector using a sleeve.

The 10073C tip is much smaller. It can't do what you describe because the tip dimensions are all much smaller. It needs a tip adaptor like the one I showed.

See the image below. The red and black probes are the vintage types and can do what you describe but the more modern 10073C (skinny grey probe) can't do this without a tip extension.

JMR,
Ahh, those adaptors are different to the ones I was thinking of. They have a separate connection between the center conductor of BNC and probe tip. This extends the length of the 50 R section. I was thinking of the plain sleeve type where the probe tip directly contacts the BNC center contact.
Details matter.......

Sorry. I use translator. I couldn't understand the words and the concept. Sorry. But I appreciate the help

Well, attempting to get sub mm perfect positioning without some sort of commercial jig would be beyond me, I'm afraid. But if it's phase sensitive measurments you want, someone further up the thread did mention using a VNA to do a S11 test on the probe and that's certainly something I can do right away if it'll help at all. I do have an HP 3Ghz VNA available and ready to go.