Test Equipment Anonymous (TEA) group therapy thread

[0culus]

Looks very nice!  How heavy is it? I suspect much less than my 8664A...that beast weighs in at about 90 lbs.

Thanks, still manageable I guess, 8.5 kg as spec, about 18 to 19 lbs.

That 8664A .. ouch. 

Yeah, it's one of those "find a place on the bench and don't move it unless you have to" instruments. 

Under 20 lbs is not bad at all! 

[0culus]

Need some opinions, I would like to pick up an Analog scope, no real need, just would like to have.  Prefer 4 channel and would like measurements, 100MHz min, no need for anything over 200.  Looking at the Tek 2247's and 2252's.  Yea or Nay or should I look at another model?

Been very happy with my 2465B...if you want I can point you at the guy I bought mine from on ebay. He refurbs and calibrates them, so you aren't buying a project.

If you're looking for Tek, I've communicated several times with user 2465b on eBay... He's a Tek nut and retired Tek tech; he helped me greatly when I was rebuilding my first 2465. I bought a few parts from him at reasonable prices, he didn't mind helping a guy DIY, and he was actually proactive with warnings about pitfalls and proper handling of those parts.

There is a seller on fleabay who reportedly rebadges 2445s as 2465s and, IIRC, puts cal stickers over everything to prevent them being opened and checked and refunds claimed.

I have no direct experience, do not know which vendor it is, but it may be worth doing some googling, particularly on the TekScopes group.

I found it: https://groups.io/g/TekScopes/topic/2465b_vs_2467/7652505?p=Created,,,20,1,0,0&jump=1

Looks like it’s the same guy. On one hand this does piss me off but I measured the 3 dB point on mine and it’s well over 400 MHz and I’ve never had a performance issue that would indicate I was working with a scope of half the bandwidth.  [edit] I just computed it again, using 6 divisions... so 20*log10(6 divisions/ approx 4.25 divisions) = 2.9952 dB down at 550 MHz. Not bad.

According to that thread, the conversion consists of removing circuits that compensate for the non-linear phase response of the delay line. That would not show up in tests using a sine wave generator, but would show up in the step response.

So the fastest edge I can generate right now is about 1.5ns (clock output from the ADF signal gen board I've been playing with.)

From the spec sheet for the 24xxB series scopes for step response rise time:

Using the approximation $$T_r = \frac{0.35}{Bandwidth}$$

2465B: >= 5 mV/div: <= 0.875 ns
2445B: <= 2.33 ns

So, as I understand it, in order to characterize the step response of the scope itself, you need a pulse generator capable of extremely fast edges, in this case faster than 875 ps if you go by the data sheet. So while I can't yet create an edge that fast, I *am* able to measure the 1.5 ns edges that I can generate. So this means that, at the very least, my hopefully-is-a-2465B is performing better than the 2445B specification. [edit] I guess what I'm getting at, is that if you put a pulse with faster rise time than the scope can resolve, what would it look like?

[tggzzz]

So her nest egg was largely consumed by these private carers so you see how our once famous NHS service is slowly coming around to being a system where it might well end up being a pay at the point of delivery much the same as your system is.

It isn't the NHS and it isn't a new problem.

The problem, which has existed for many decades, is the divide between care for medical purposes (NHS, central government) and care for social purposes (local authorities).

There have been political attempts to remove that artificial divide; the latest are still being tried e.g. in Manchester.

[tggzzz]

found a replacement neon for my HP 6284A finally. Took ages. It's an A1H neon which is impossible to find in the UK. Turns out that it's also an SX6s which is available on ebay fortunately here for £4 for a 5 pack. Phew - thought I was going to have to invoke an american supplier over that one.

Auction with SX6s in it: https://www.ebay.co.uk/itm/222115042772

I'm sure that you could have Macgyvered another neon solution for it? It is the pilot lamp right?   

Yeah I didn't want to do anything too nasty there. It's a nice Oak brand switch with integrated neon pilot lamp. You unscrew the top and there's a little midget flange neon you just pop out. Seemed a shame not to do a proper job.

So her nest egg was largely consumed by these private carers so you see how our once famous NHS service is slowly coming around to being a system where it might well end up being a pay at the point of delivery much the same as your system is.

Totally agree with this.

I wouldn't bother paying for it. Honestly I looked at two major private healthcare providers here in the UK and you've got about 3 months extra cover on top for around £900 a year and then they wheel you into the street and tell you to fuck off. Not worth it. Most of the hospices are run off donations here as well. I donate to https://www.pah.org.uk/ regularly.

Simple observation: insurance (or pre-paid plans) for any purpose have to cost more, since they have to include admin and profit overheads. You should only buy insurance for X if you can't afford the consequences of X and the insurance is cheaper than X (or you don't trust those around you to keep the savings for X safe).

My GP said it all a couple of years ago. She was diagnosed with stage 4 breast cancer and committed suicide after 2 months (helium bag over head) rather than take the care option. That left her estate intact for her family and saved her the suffering. A brave woman who I have nothing but respect for.

The paywalled article https://www.wsj.com/articles/SB10001424052970203918304577243321242833962 made an interesting point about US doctors. Essentially many of them decline treatment options that they suggest their patients have; the doctors know how miserable the treatments and outcomes are and choose to enjoy what time is left to them.

My mother declined to have surgery to replace an aortic valve, since the valve wasn't causing the symptoms that continue to give her most trouble.

[tggzzz]

Need some opinions, I would like to pick up an Analog scope, no real need, just would like to have.  Prefer 4 channel and would like measurements, 100MHz min, no need for anything over 200.  Looking at the Tek 2247's and 2252's.  Yea or Nay or should I look at another model?

Been very happy with my 2465B...if you want I can point you at the guy I bought mine from on ebay. He refurbs and calibrates them, so you aren't buying a project.

If you're looking for Tek, I've communicated several times with user 2465b on eBay... He's a Tek nut and retired Tek tech; he helped me greatly when I was rebuilding my first 2465. I bought a few parts from him at reasonable prices, he didn't mind helping a guy DIY, and he was actually proactive with warnings about pitfalls and proper handling of those parts.

There is a seller on fleabay who reportedly rebadges 2445s as 2465s and, IIRC, puts cal stickers over everything to prevent them being opened and checked and refunds claimed.

I have no direct experience, do not know which vendor it is, but it may be worth doing some googling, particularly on the TekScopes group.

I found it: https://groups.io/g/TekScopes/topic/2465b_vs_2467/7652505?p=Created,,,20,1,0,0&jump=1

Looks like it’s the same guy. On one hand this does piss me off but I measured the 3 dB point on mine and it’s well over 400 MHz and I’ve never had a performance issue that would indicate I was working with a scope of half the bandwidth.  [edit] I just computed it again, using 6 divisions... so 20*log10(6 divisions/ approx 4.25 divisions) = 2.9952 dB down at 550 MHz. Not bad.

According to that thread, the conversion consists of removing circuits that compensate for the non-linear phase response of the delay line. That would not show up in tests using a sine wave generator, but would show up in the step response.

So the fastest edge I can generate right now is about 1.5ns (clock output from the ADF signal gen board I've been playing with.)

From the spec sheet for the 24xxB series scopes for step response rise time:

Using the approximation $$T_r = \frac{0.35}{Bandwidth}$$

2465B: >= 5 mV/div: <= 0.875 ns
2445B: <= 2.33 ns

So, as I understand it, in order to characterize the step response of the scope itself, you need a pulse generator capable of extremely fast edges, in this case faster than 875 ps if you go by the data sheet. So while I can't yet create an edge that fast, I *am* able to measure the 1.5 ns edges that I can generate. So this means that, at the very least, my hopefully-is-a-2465B is performing better than the 2445B specification. [edit] I guess what I'm getting at, is that if you put a pulse with faster rise time than the scope can resolve, what would it look like?

That's pretty much it. A clean but slow edge could demonstrate the presence of problems, but not their absence.

If you have a faster edge (i.e. not a "useless" pulse), then the result should be a trace with a smoothly rising edge, a little overshoot (as per scope's specification), and little ripple.

[beanflying]

When you thought you knew them all...has anyone heard of NF Corporation?
https://www.nfcorp.co.jp/english/index.html

And any experience with their products?

Also, can anyone say something about Quadtech?

Quadtech/Zentech make nice gear. My Milliohmmeter works great and is well designed. From what I gather Chroma in the USA was their distributor and now owns and has absorbed them.

[0culus]

Need some opinions, I would like to pick up an Analog scope, no real need, just would like to have.  Prefer 4 channel and would like measurements, 100MHz min, no need for anything over 200.  Looking at the Tek 2247's and 2252's.  Yea or Nay or should I look at another model?

Been very happy with my 2465B...if you want I can point you at the guy I bought mine from on ebay. He refurbs and calibrates them, so you aren't buying a project.

If you're looking for Tek, I've communicated several times with user 2465b on eBay... He's a Tek nut and retired Tek tech; he helped me greatly when I was rebuilding my first 2465. I bought a few parts from him at reasonable prices, he didn't mind helping a guy DIY, and he was actually proactive with warnings about pitfalls and proper handling of those parts.

There is a seller on fleabay who reportedly rebadges 2445s as 2465s and, IIRC, puts cal stickers over everything to prevent them being opened and checked and refunds claimed.

I have no direct experience, do not know which vendor it is, but it may be worth doing some googling, particularly on the TekScopes group.

I found it: https://groups.io/g/TekScopes/topic/2465b_vs_2467/7652505?p=Created,,,20,1,0,0&jump=1

Looks like it’s the same guy. On one hand this does piss me off but I measured the 3 dB point on mine and it’s well over 400 MHz and I’ve never had a performance issue that would indicate I was working with a scope of half the bandwidth.  [edit] I just computed it again, using 6 divisions... so 20*log10(6 divisions/ approx 4.25 divisions) = 2.9952 dB down at 550 MHz. Not bad.

According to that thread, the conversion consists of removing circuits that compensate for the non-linear phase response of the delay line. That would not show up in tests using a sine wave generator, but would show up in the step response.

So the fastest edge I can generate right now is about 1.5ns (clock output from the ADF signal gen board I've been playing with.)

From the spec sheet for the 24xxB series scopes for step response rise time:

Using the approximation $$T_r = \frac{0.35}{Bandwidth}$$

2465B: >= 5 mV/div: <= 0.875 ns
2445B: <= 2.33 ns

So, as I understand it, in order to characterize the step response of the scope itself, you need a pulse generator capable of extremely fast edges, in this case faster than 875 ps if you go by the data sheet. So while I can't yet create an edge that fast, I *am* able to measure the 1.5 ns edges that I can generate. So this means that, at the very least, my hopefully-is-a-2465B is performing better than the 2445B specification. [edit] I guess what I'm getting at, is that if you put a pulse with faster rise time than the scope can resolve, what would it look like?

That's pretty much it. A clean but slow edge could demonstrate the presence of problems, but not their absence.

If you have a faster edge (i.e. not a "useless" pulse), then the result should be a trace with a smoothly rising edge, a little overshoot (as per scope's specification), and little ripple.

Thanks! OK, so on further inspection, the falling edge of this clock signal is actually faster. Here's photos of both. Rising edge is a bit more than I originally stated (my bad). Signal is 25 MHz, terminated into a 50 ohm thru terminator so I could leave the scope set at 1 Mohm AC coupled.

[kj7e]

I was looking at the Tek scopes on eBay just now, and accidentally bought an HP 53310 with Option 31 (2.5GHz) instead 

I could not pass up it up.  https://www.ebay.com/itm/Agilent-HP-53310A-Modulation-Domain-Analyzer-10Hz-2-5GHz-Opt-031/183650891045?ssPageName=STRK%3AMEBIDX%3AIT&_trksid=p2057872.m2749.l2649

[bitseeker]

So, you Bob Rossed it ("happy accident")?

Hmm, TEA is like painting because...

[bitseeker]

New toy arrived, I assume this thingy will blink my led much better than my 555 signal generator right ?

A right and proper upgrade to your 555-based generator.

[0culus]

I was looking at the Tek scopes on eBay just now, and accidentally bought an HP 53310 with Option 31 (2.5GHz) instead 

I could not pass up it up.  https://www.ebay.com/itm/Agilent-HP-53310A-Modulation-Domain-Analyzer-10Hz-2-5GHz-Opt-031/183650891045?ssPageName=STRK%3AMEBIDX%3AIT&_trksid=p2057872.m2749.l2649

Very cool. Why would they call it a modulation analyzer instead of just calling it an oscilloscope?

[kj7e]

I was looking at the Tek scopes on eBay just now, and accidentally bought an HP 53310 with Option 31 (2.5GHz) instead 

I could not pass up it up.  https://www.ebay.com/itm/Agilent-HP-53310A-Modulation-Domain-Analyzer-10Hz-2-5GHz-Opt-031/183650891045?ssPageName=STRK%3AMEBIDX%3AIT&_trksid=p2057872.m2749.l2649

Very cool. Why would they call it a modulation analyzer instead of just calling it an oscilloscope?

Its actually a frequency analyzer, really cool piece of equipment to analyze phase noise and short term stability of signals.  It has more in common with a spectrum analyzer than an oscilloscope.  It makes a really nice frequency counter as well.

Video explaining what the heck a Modulation Domain Analyzer is good for;


There is a Tek scope I think I'm going to bid on, just biding my time not to inflate the price, will know more soon...

[0culus]

Ah I see. That should be a useful addition to the lab 

[kj7e]

I'm on a TE bender, just won a Tek 2247A, put in a bid at the 20 sec mark and won 

https://www.ebay.com/itm/192876517003

[0culus]

Keep it coming!  I love living vicariously through other people's TEA. 

[Brumby]

Keep it coming!  I love living vicariously through other people's TEA. 

[mnementh]

   New toy arrived, I assume this thingy will blink my led much better than my 555 signal generator right ?

A right and proper upgrade to your 555-based generator.

https://shop.evilmadscientist.com/productsmenu/tinykitlist/652#

Did somebody say 555 Timer Upgrade ? 

mnem
Off. Slightly.

[VK5RC]

Time-nuttery alert!
Re the 53310, modulation / phase analzer, have you guys seen the TAPR project the time interval counter TICC, does continuous time stamping measurement, in the few 10s of pS, for USD $205. About 1/30 of keysight 's 53230A!
https://www.tapr.org/kits_ticc.html
Rob

[0culus]

   New toy arrived, I assume this thingy will blink my led much better than my 555 signal generator right ?

A right and proper upgrade to your 555-based generator.

https://shop.evilmadscientist.com/productsmenu/tinykitlist/652#

Did somebody say 555 Timer Upgrade ? 

mnem
Off. Slightly.

Is that thing a real, functioning 555? That would make a fun thing to have on your desk. [edit] dammit, it is...I gotta have one now... 

[beanflying]

   New toy arrived, I assume this thingy will blink my led much better than my 555 signal generator right ?

A right and proper upgrade to your 555-based generator.

https://shop.evilmadscientist.com/productsmenu/tinykitlist/652#

Did somebody say 555 Timer Upgrade ? 

mnem
Off. Slightly.

Is that thing a real, functioning 555? That would make a fun thing to have on your desk. [edit] dammit, it is...I gotta have one now... 

But of course and even featured in Video 555 

[bitseeker]

Time-nuttery alert!
Re the 53310, modulation / phase analzer, have you guys seen the TAPR project the time interval counter TICC, does continuous time stamping measurement, in the few 10s of pS, for USD $205. About 1/30 of keysight 's 53230A!
https://www.tapr.org/kits_ticc.html
Rob

You tease! (out of stock )

[worsthorse]

I arrived home from my folks house to find the second TG501 I ordered had arrived. I figured I would be able to build one good one out of the two I found on ebay that didn't cost 150USD.  Here's what I am starting with...



A plastic shaft on the first one (on the right) was sheared off and the time adjustment knob pretty badly damaged. After doing a visual check, I powered it up and it works, more or less. The second purchase was, I knew, beat up but yikes...





It looks like someone drove over it. When I got the side cover off, things are pretty grim. Broken trimmer caps, etc. Two redeeming features: it has the option 1 oscillator installed and the shaft and knobs aren't damaged:





I can use both of those on the first plug-in.

I spent a pleasant hour dis-assembling the battered unit and extracting parts. There are a lot of small ceramic trimmers, inductors, and other random goodies, like the display board, to salvage. And it looks like I will get one good TG501 out of the two of them, so the busted up one was worth the fifty bucks it cost me, methinks.

[beanflying]

I arrived home from my folks house to find the second TG501 I ordered had arrived. I figured I would be able to build one good one out of the two I found on ebay that didn't cost 150USD.  Here's what I am starting with...

A plastic shaft on the first one (on the right) was sheared off and the time adjustment knob pretty badly damaged. After doing a visual check, I powered it up and it works, more or less. The second purchase was, I knew, beat up but yikes...

It looks like someone drove over it. When I got the side cover off, things are pretty grim. Broken trimmer caps, etc. Two redeeming features: it has the option 1 oscillator installed and the shaft and knobs aren't damaged:

I can use both of those on the first plug-in.

I spent a pleasant hour dis-assembling the battered unit and extracting parts. There are a lot of small ceramic trimmers, inductors, and other random goodies, like the display board, to salvage. And it looks like I will get one good TG501 out of the two of them, so the busted up one was worth the fifty bucks it cost me, methinks.

  Where did the battered one come from an Israeli  Bulldozer sorted salvage yard?

[Brumby]

Oooof ... yes.

I hope the poor thing died quickly and didn't suffer too much.

[tautech]

What's the bet when it wouldn't work the previous plugin caretaker  yanked it out and biffed it on the floor and then either stuck the boot in  or played soccer with it.

Shame it wasn't rescued before suffering that indignity.