FYI, Siglent are working on a manual Cal procedure so that owners can tweak measurements once their SDM's have aged. Not all measurement types will be tweakable AFAIK, just those for which you budding volt/ohm/amp nuts carry the typical standard references.
Actually, must check how things are progressing with this manual Cal ..................
That would be great! Keep me informed. Thanks
Now I need to make myself a couple of pieces of Vegemite toast.
That shit sounds nasty.
Nasty is too strong a word. "Too sweet" is appropriate for those accustomed to The Real Thing: Marmite
Good deal! Sounds like the BFO is now working, correct?
yes. I have forgotten a bridge on the coil
Now I need to make myself a couple of pieces of Vegemite toast.
That shit sounds nasty.
Nasty is too strong a word. "Too sweet" is appropriate for those accustomed to The Real Thing: Marmite
To me anything classified as "too sweet" is nasty to me. I've never been a fan of real sweet stuff. Things that make your teeth cringe when you bite into it. Even before I was diabetic.
Now I need to make myself a couple of pieces of Vegemite toast.
That shit sounds nasty.
Nasty is too strong a word. "Too sweet" is appropriate for those accustomed to The Real Thing: Marmite
Marmite is very close in consistency to cigarette tar in any reasonable concentration. Doesn’t taste much better either. Best use for it was fucking up a rental we had. We decorated the place then he kicked us out because it was worth more. So we redecorated it again with marmite.
I thought I saw the entry-level FLIR with native VGA res at around $1k a while back...? What’s the diff; pixel-by-pixel accuracy?
mnem
Less noise, more consistent performance, likely a better framerate. It's a different class of instrument and though technology marches on thermal imaging doesn't appear to be moving as quickly as some other areas.
Now I need to make myself a couple of pieces of Vegemite toast.
That shit sounds nasty.
Nasty is too strong a word. "Too sweet" is appropriate for those accustomed to The Real Thing: Marmite
Marmite is very close in consistency to cigarette tar in any reasonable concentration. Doesn’t taste much better either. Best use for it was fucking up a rental we had. We decorated the place then he kicked us out because it was worth more. So we redecorated it again with marmite.
The mind boggles as to how and why you ended up tasting cigarette tar
My "hope to find" list for the hamfest was short: GR874 and N adapters to use at my bench. My first tour round the selling tables revealed a cardboard box full of GR874s. Next to it was a mixed box of adapters, with a goodly number of N type. Here's what I scooped up:
But I not only found a few pounds of adapters, I picked up an almost complete set of Tektronix GR attenuators (2X, 5X, 10X), oscilloscope and DMM voltage pickoffs, a 10% sampling coupler, and a paired 50 ohm load and short:
There was a capacitive coupler in the box, too, which I forgot to put in the pile. I didn't realize that until I got home.
The grand total?
23USD. I couldn't believe it and accepted the ask without further negotiation!
The seller offered to sell me the rest of the GR box for another ten bucks. I passed on it, though with some misgivings.
Photos of the impulsive TE purchases to follow.
I thought I saw the entry-level FLIR with native VGA res at around $1k a while back...? What’s the diff; pixel-by-pixel accuracy?
mnem
Less noise, more consistent performance, likely a better framerate. It's a different class of instrument and though technology marches on thermal imaging doesn't appear to be moving as quickly as some other areas.
Okay... a little research shows the difference.
The ones I was thinking of have progressed; they're a lot cheaper now too... but the actual hardware isn't what I thought it was. Way lower native IR res than the one Kosmic has, and due to the fact it multi-scans and stitches the images together to make a larger image, net is less than 8fps.
That kindof puts Kosmic's score in much better perspective.
mnem
The -- hp -- 428b verification procedure is steadily and slowly advancing. Built a little voltage divider box for the cal from a plastic mini Hammond box, 3 Chinesium binding posts and 2 hand-selected Vishay 1K 1% resistors that the -- hp -- 974A declared were 0,1 Ω from each other. (428b manual says one should select these carefully for similar values.) The -- hp --427a (hi, bd139!) said there was 22mV on the centre of the divider when used as directed in the oscillator circuit, which is in-spec ("under 50mV"). Oscillator frequency is now 40KHz, not 39980Hz (which was also in-spec, though), according to the -- hp -- 5221A (yes, Nixies at work here. Wonderful.), and the oscillator level is 8,02V, according to the Marconi VTVM, which is in-spec. My ScopeMeter was very finicky and did not want to auto-trig on the waveform; it took almost CRO amounts of fettling the controls to get it to display anything sensible.
All vintage instruments have had a modern sanity check made in parallel, because even if the person with two clocks always wonders which one is right, the observation that they roughly agree the next day too is somewhat reassuring. The -- hp -- 974a really is an excellent DMM, steadily getting a good measurement off of the DUT.
All in all, so far every measurement has been within tolerance. This instrument must have been put aside at a very young age, probably because it blew fuses, and then just been a Sleeping Beauty waiting for someone to take it to bits and figure out what was wrong with it.
This is bordering on obsession, but I've got my reasons, and I like to think they're on track for a group of T.E.A. afficionados...
My "hope to find" list for the hamfest was short: GR874 and N adapters to use at my bench. My first tour round the selling tables revealed a cardboard box full of GR874s. Next to it was a mixed box of adapters, with a goodly number of N type. Here's what I scooped up:
But I not only found a few pounds of adapters, I picked up an almost complete set of Tektronix GR attenuators (2X, 5X, 10X), oscilloscope and DMM voltage pickoffs, a 10% sampling coupler, and a paired 50 ohm load and short:
There was a capacitive coupler in the box, too, which I forgot to put in the pile. I didn't realize that until I got home.
The grand total? 23USD. I couldn't believe it and accepted the ask without further negotiation!
The seller offered to sell me the rest of the GR box for another ten bucks. I passed on it, though with some misgivings.
Photos of the impulsive TE purchases to follow.
Dang, that's a nice grab. I was able to restrict myself to buying radio related stuff this time.
Now I need to make myself a couple of pieces of Vegemite toast.
That shit sounds nasty.
Nasty is too strong a word. "Too sweet" is appropriate for those accustomed to The Real Thing: Marmite
Marmite is very close in consistency to cigarette tar in any reasonable concentration. Doesn’t taste much better either. Best use for it was fucking up a rental we had. We decorated the place then he kicked us out because it was worth more. So we redecorated it again with marmite.
The mind boggles as to how and why you ended up tasting cigarette tar
Mmmm Vegemite
Unless you grow up with it the taste buds will take some acclimatization.
Given a serving is maybe 1-2g and the Sugar content of Vegemite is circa 2% (local Marmite is over 10% unlike the sour UK 1% Version
) it is unlikely to ever cause a diabetic reaction.
My "hope to find" list for the hamfest was short: GR874 and N adapters to use at my bench. My first tour round the selling tables revealed a cardboard box full of GR874s. Next to it was a mixed box of adapters, with a goodly number of N type. Here's what I scooped up:
But I not only found a few pounds of adapters, I picked up an almost complete set of Tektronix GR attenuators (2X, 5X, 10X), oscilloscope and DMM voltage pickoffs, a 10% sampling coupler, and a paired 50 ohm load and short:
There was a capacitive coupler in the box, too, which I forgot to put in the pile. I didn't realize that until I got home.
The grand total? 23USD. I couldn't believe it and accepted the ask without further negotiation!
The seller offered to sell me the rest of the GR box for another ten bucks. I passed on it, though with some misgivings.
Photos of the impulsive TE purchases to follow.
Dang, that's a nice grab. I was able to restrict myself to buying radio related stuff this time.
Given that we transferred some antipodes-to-europe just a few months ago, indeed.
More volt-nttery. Today's mission is to certify the Siglent SDM 3055 as my “Bench 2 Standard”. I've had this Siglent for almost a year now and while I like it overall there are a few items that annoy me. First, it doesn't match up exactly with either AD584-M references. It's always measured consistently low as seen as the chart. It's close but no cigar. Sloppy factory calibration or are BOTH references off? Who knows but to me 5.5 digits is overkill anyway. Second, I found that there is no difference in warm up times from either a cold start (power completely off) or power up from standby. Takes at least 12 hours for both for best accuracy. That tells me that standby does not keep the internal voltage reference hot which makes it totally useless and just consumes power. Perhaps Tautech can confirm this.
For this exercise the Siglent was powered up for 48 hours. It has confirmed via cross checking that the Fluke 8050A is a valid bench 1 standard. And it further convinced me that for my needs 4.5 digits is more than enough. 5.5 digits is overkill and I'll never venture into 6.5 digit territory. Especially when I see these 6.5 digit and greater DMM's all stacked up and connected to the same source and all reading differently. That would drive me to drink.
When you get into 4th digits and above you will really need to start looking at spec & datasheets for long and short term drift plus a bunch of ethereal fudge factors. Your Siglent for example may now have NEARLY enough hours on it for the reference to have settled to a more stable number but I doubt your AD584's have.
My two Agilent/Keysight 6 1/2 digit meters have opposing temperature coefficients of seemingly similar numbers against an my ovenised references. At 20C they are within 2ppm. Still both within spec but something I recognize. If that same drift at 5C shift in temperature was applied to your meters for example it would be see a shift in your meter if they were similar shift a LSD or two. Add that to a cheap and cheerful but unknown reference (other than assuming it matches the datasheet) you could easilly slip several more COMBINED.
This is WHY YOU NEED 6 1/2 Digits to test your others to then be uncertain about it
This is WHY YOU NEED 6 1/2 Digits to test your others to then be uncertain about it
Absolutely agree
100% med needs 6.5 digits for sure no question about it.
The bridge is ok.
30000pF 0.5% Koweg Capacitor
20kOhm 0.1%
So, into the breach again - looking for everything that fits that Lemo. (I need 4W tweezers,4W clips and a SMD-Adaptor. Will consider altering other makes, will not consider crap)