Products > Test Equipment
Test Equipment Anonymous (TEA) group therapy thread
Vince:
Yeah sure, but I meant, of course, it wasn't at all back in the day of this Tek fixture...
I see the Leonardo and the chip you mentionned both are about 30ps.
That's only a factor of two or better than what this Tek fixture managed 60 years prior.
I find it quite embarrassing actually... certainly nothing to brag about I would think.
I might order some of those chips you mentioned to see what I can do.
However I suspect that the actual rise time of this chip might be heavily influenced by the board layout and practical implementation overall.
So I would have no idea what rise time I am actually getting out of a complete, finished product, no ? Or am I being too pessimistic ?!....
Are there "reference" / proven designs and board layouts out there for this chip ?
Still want that Tek fixture. It's just so sexy, and unlike the Leonardo it does not require USB and a Windows computer I don't want, to configure it. The Tek has a built-in human interface so to speak, and only need mains. Much more practical, intuitive and straight forward to me...
The cheapest Leonardo is extremely, extremely compact though, it's plus for sure. But at 150 Euros it's a lot of money for what it is... I guess you pay for the labour involved in testing each and every unit.
tautech:
--- Quote from: Vince on Yesterday at 05:47:00 pm ---Yeah sure, but I meant, of course, it wasn't at all back in the day of this Tek fixture...
I see the Leonardo and the chip you mentionned both are about 30ps.
That's only a factor of two or better than what this Tek fixture managed 60 years prior.
I find it quite embarrassing actually... certainly nothing to brag about I would think.
I might order some of those chips you mentioned to see what I can do.
However I suspect that the actual rise time of this chip might be heavily influenced by the board layout and practical implementation overall.
So I would have no idea what rise time I am actually getting out of a complete, finished product, no ? Or am I being too pessimistic ?!....
Are there "reference" / proven designs and board layouts out there for this chip ?
Still want that Tek fixture. It's just so sexy, and unlike the Leonardo it does not require USB and a Windows computer I don't want, to configure it. The Tek has a built-in human interface so to speak, and only need mains. Much more practical, intuitive and straight forward to me...
The cheapest Leonardo is extremely, extremely compact though, it's plus for sure. But at 150 Euros it's a lot of money for what it is... I guess you pay for the labour involved in testing each and every unit.
--- End quote ---
Unfortunately you are a bit late to the Leo Bodnar Pulser party as just a few months ago a dumb pulser from Leo was available for 50 quid.
They were rated at 10 MHz and with 40ps rise/fall times tested on a 20 GHz sampling scope.
Mine arrived with 28ps rise/fall screenshots.....
I was going to build one with a 7414 IC and had it all drawn up in Altium but knew it wouldn't every get into the 10's of ps.
Vince:
Yes I did see it on their website, marked as "Obsolete". Was 40ps but more like100 Euros so still very expensive for what it is.
I guess there is not much on that minuscule board so probably someone will reverse engineer it and Gerber files will be available ?
Probably been already done, somewhere on the forum, I guess...
That being said, when you think about it even 30ps is still very slow to check fast-ish scopes.
My fastest scope is 3GHz, a TDDS694C, and if I get my math right that's about 117ps rise time.
So even 30ps is hardly negligible. you can still work out the rise time of the scope but it takes an extra step/calculation.
For all my other scopes though, the 42 of them... it's plenty good enough...
I wonder what kind of voodoo goes into making a pulser for say a 100GHz scope...
factory:
The mention of 3DP at the end of last year, encouraged me to get some feet made for the snap together HP instruments from the 1970s, eg the 5300 series, 34740/50 series. 3311A use the same style of case.
I really hope they aren't as described on the packaging, we need the opposite. :-DD
They will need some adjustment, for some unknown reason they are not symmetrical and one of the holes doesn't line up quite right, having more made isn't an option, these weren't cheap enough for that. Shouldn't be too difficult to adjust, just attack with a file & drill.
P.S. The design file is from this post; https://www.eevblog.com/forum/testgear/replacement-knobs-feet-and-fittings-for-test-equipment/msg2472369/#msg2472369
David
44kgk1lkf6u:
--- Quote from: Vince on Yesterday at 05:47:00 pm ---I might order some of those chips you mentioned to see what I can do.
However I suspect that the actual rise time of this chip might be heavily influenced by the board layout and practical implementation overall.
So I would have no idea what rise time I am actually getting out of a complete, finished product, no ? Or am I being too pessimistic ?!....
Are there "reference" / proven designs and board layouts out there for this chip ?
--- End quote ---
Onsemi Motorola provides an evaluation board for NB7L14. It is more expensive than the Bodnar thing. I failed to find its design files.
I don't have a 3 GHz oscilloscope. I only needed something fast enough for my 1 GHz oscilloscope. I put the chip and an LVDS oscillator on a 2 layer PCB without the fancy controlled impedance stuff. It only needs a -3.3 V power supply. Measuring on a 7.1 GHz spectrum analyzer showed that its knee frequency is likely faster than what the spectrum analyzer can measure. It did not feel right to measure an oscilloscope, and then buy a sampling oscilloscope just to measure what measures it. I did not optimize the board because the first version was already good enough. I can upload the design if you want it.
Navigation
[0] Message Index
[#] Next page
[*] Previous page
Go to full version