USA Cal Club: Round 2

[orin]

I know I said I would follow a random participant order, but I'm going to violate that rule and send it off to kj7e next, to take advantage of his recent calibration 

Well, that sounds like a good exception to the rule.

And FWIW, take me out of the rotation for the first two weeks of September.

For obvious reasons, it might be a good idea to let cellularmitosis know of your vacation plans... (privately, even though I just violated that idea).

[vindoline]

I'm fine with the idea of randomizing the order of the list. It might be a good idea though to pick the order of the list now so that participants have a rough idea of when their turn is. This can help us to be prepared and more efficient during our turn.

[CatalinaWOW]

Even if you don't pick or publish the entire list now, it would be good to have a month or two of warning, both for preparation on our end, and to give time for feedback to you if we aren't going to be available.  Obviously all of our plans change from time to time, but most of us do have some major plans of some sort.

[dr.diesel]

Even if you don't pick or publish the entire list now, it would be good to have a month or two of warning, both for preparation on our end, and to give time for feedback to you if we aren't going to be available.  Obviously all of our plans change from time to time, but most of us do have some major plans of some sort.

That's a good point, but tough considering an unknown turn-around time for each tester.

Perhaps just the list, so one would know they are next?  I'm for example gone about 40% of the warm months, so at least some flexibility needs to be considered.

[cellularmitosis]

Good ideas / concerns around scheduling -- I'll get the list made and published.

[TiN]

But then you will not have surprise guests,  .
And I'm still waiting on resistors. 

[cellularmitosis]

This is a good point .  There might have to be a few more rule violations

[bitseeker]

Include some entries marked "RESERVED" or "? ? ? ? ?" to enable surprises, sudden schedule changes, and future rule violations.

[Svgeesus]

Speaking of participant order, I will be away on foreign travel from the last week of June until the first week of September. Still able to read and post, but no access to my equipment while traveling.

[ArthurDent]

A continually updated list would be a good idea because things can change quickly and unexpectedly. Ten days ago I was putting the final touches on my first Dr Frank board, which was looking good, when I decided to clean all the remaining flux off the board before permanently mounting it in the enclosure. After adding a transistor buffer for the 10V output, making a few changes, and selecting the trim resistors, it needed cleaning. Part way through the cleaning I heard a click from my power supply and suddenly realized I hadn’t disconnected the power before mucking with the board and the click I heard was the supply going into current limit. I checked and the 7 volt output from the LTZ1000A was now 12 volts. DAMN!

My second board is looking good and I hope to have the replacement LTZ1000A for the first board in any day now. I’ll be more careful with this one and both boards should be ready by the time my turn comes up.

[CalMachine]

A continually updated list would be a good idea because things can change quickly and unexpectedly. Ten days ago I was putting the final touches on my first Dr Frank board, which was looking good, when I decided to clean all the remaining flux off the board before permanently mounting it in the enclosure. After adding a transistor buffer for the 10V output, making a few changes, and selecting the trim resistors, it needed cleaning. Part way through the cleaning I heard a click from my power supply and suddenly realized I hadn’t disconnected the power before mucking with the board and the click I heard was the supply going into current limit. I checked and the 7 volt output from the LTZ1000A was now 12 volts. DAMN!

My second board is looking good and I hope to have the replacement LTZ1000A for the first board in any day now. I’ll be more careful with this one and both boards should be ready by the time my turn comes up.

Ouch!!  I've done something similar awhile back. I desoldered the output and power wires after a test, while the power was still on lol.  Thankfully the LTZ seemed to have went unscathed. 

[hwj-d]

I think, it's probably too expensive to send something to germany back and forth (heard something like 60-80$). So, my participation can't be not more like quiet rhetorical, after spending one of my refs to cellular USA Cal Club (I hope, I still get it on the line, next time ). So, please take me out of list.  Good luck to the club 

[Andreas]

I think, it's probably too expensive to send something to germany back and forth (heard something like 60-80$).

It mainly depends on the weight. And the service that you use.
from here to US it is 3,70 Eur below 500g (if you send it as letter) + 2,50 Eur for tracking (Einschreiben)
or 7 Eur below 1000g. (+ the tracking).
Of course the value of the content should be below the customs limits otherwise there are customs fees.

From US to D I payed between 7.10$ and 23.50$ for resistors from Edwin depending on USPS service.
So it is somewhat more but not 60$.

with best regards

Andreas

[cellularmitosis]

The other night I threw the ref into a small styrofoam ice chest along with the temperature logger and a tupperware container full of hot water.  A temperature controller would be better, but this was something I could do quickly in the time I had available.  The ref was hooked up to my Keithley 2015 (the same I've used in previous measurements for this ref).

Interestingly, it looks like the ref by itself has a negative temperature coefficient (in this temperature range).  Previously, when I had adjusted the aircon (and thus measured the combined tempco of the ref and my meter), I had measured a positive tempco: https://www.eevblog.com/forum/metrology/usa-cal-club-round-2/msg1516561/#msg1516561

The ref is packaged up and I'm about to run by the post office to send it off to kj7e (I hope they are still open on Saturday past noon!).

[kj7e]

Looking forward to it.  I have a short list of tests I want to run.  0.1-10Hz noise, 1 hour and 24 hour stability and comparison to my references at a steady 23C,  TC sweeps from 10C to 40C and back, another stability test at 23C after the TC sweep, loading the output at 10G, 10M, 1M and 100K effects, maybe add in some EMI tests with shielded and non-shielded test leads.

[hwj-d]

I think, it's probably too expensive to send something to germany back and forth (heard something like 60-80$).

It mainly depends on the weight. And the service that you use.
from here to US it is 3,70 Eur below 500g (if you send it as letter) + 2,50 Eur for tracking (Einschreiben)
or 7 Eur below 1000g. (+ the tracking).
Of course the value of the content should be below the customs limits otherwise there are customs fees.

From US to D I payed between 7.10$ and 23.50$ for resistors from Edwin depending on USPS service.
So it is somewhat more but not 60$.

with best regards

Andreas

That sounds better.
My info was from ups. They told me, the cheapest from germany to USA, value of goods 10€, is 'UPS Expedited', plus fuel surcharge 15€, plus private delivery, incl., something about 90€. (Send it as letter with this outer dimension like a packed Hammond 1590B not possible)

[Andreas]

A international letter can also be in a card box (not only a jiffy bag)
(maximum size l + w + h = 90 cm)

https://www.deutschepost.de/de/produkte.html

[hwj-d]

A international letter can also be in a card box (not only a jiffy bag)
(maximum size l + w + h = 90 cm)

Will ask Deutsche Post for that.
But, that also has to be done by customs. As i understood, handling flats for that are the expensive part. I don't want to cellular, that he suddenly has to pay customs and other costs.

[cellularmitosis]

When I shipped resistors to Andreas it wasn’t that expensive, I don’t recall the exact amount but it was deifninitely under $20.  At the rate this club is going, this is a pretty cheap hobby, so don’t worry about it Hwj-d

[vindoline]

Looking forward to it.  I have a short list of tests I want to run.  0.1-10Hz noise, 1 hour and 24 hour stability and comparison to my references at a steady 23C,  TC sweeps from 10C to 40C and back, another stability test at 23C after the TC sweep, loading the output at 10G, 10M, 1M and 100K effects, maybe add in some EMI tests with shielded and non-shielded test leads.

Sounds like a great set of benchmark tests for the ref!

[hwj-d]

When I shipped resistors to Andreas it wasn’t that expensive, I don’t recall the exact amount but it was deifninitely under $20.  At the rate this club is going, this is a pretty cheap hobby, so don’t worry about it Hwj-d

I've been careful with this, after arrow, at this time as the ltz1000 had elsewhere delivery problems, send me one with dhl in a 'huge' packet. Dhl demanded customs duty and handling flat at delivery time, that more as doubles the price. I didn't accept the part with that delivery costs. After that i saw in online delivery protocoll, that dhl "parked" that package for more than one month in their hand-over stock, before they give it back to arrow. Luckily i got my money back from paypal.

Edit: But with ~20$ i'm in again. Thank you cellular. 

[2N3055]

Try Mouser next time. It has free shipping over 50USD. I'm in Croatia, so pretty much same as Germany...
They ship some from EU, and some from USA, but no difference for you.  They don't have LTZ1000 on stock now but they will at the end of July...

Regards,

Sinisa

[hwj-d]

Try Mouser next time. It has free shipping over 50USD. I'm in Croatia, so pretty much same as Germany...
They ship some from EU, and some from USA, but no difference for you.  They don't have LTZ1000 on stock now but they will at the end of July...

Regards,

Sinisa

Hi Sinisa,
yes, Digikey the same. They need 3 days to deliver from Thief River Falls to me. Big german distributors haven't completet the package in this time... 

[kj7e]

Package arrived this afternoon.  First test was a power on warmup plot.  The reference had been sitting in the lab at 23C for about an hour, then powered up to see how long it would take before it settled down.  First screen shot is 1 hour, so it took about 30 min for things to warm up in the tin enclosure.  Second screen shot is a 5 hour plot,  my wife turned off the room A/C around the 13K sec mark, you can see how the plot stabilized some.  Tomorrow I will have to see if this is the reference or my meter showing the thermal sensitive.

Off the bat, I am measuring ~5ppm lower than cellularmitosis.

[Vgkid]

Looks like I don't need to worry about my multimeters being too drifty.