Is there by any chance you tested 512-BC33740TA and 512-BC32740TA from Mouser with Hesener circuit as well?
I measure all mine with a Peak DCA Pro meter, and then curve trace my final selection once they're batched up. Time consuming but worth it. The last lot I did ended up giving only 0.5v offset with the servo out of circuit. That's very good. A typical 10% accuracy match will yield about 2.5v offset before the servo.
Ime you can clearly hear the difference between 1% and 10% matched parts..
Ime you can clearly hear the difference between 1% and 10% matched parts..
First of all, thanks for your vast contributions on this project.
I'm considering buying another batch of 327 and 337 and since the Diotec I've got are having HFE all over the place.
Since I'm located near the region where Mazzer is, I thought maybe I checked with him since the supply chain should be from the same source.
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I ordered another 200 each of the 512-BC33740TA and 512-BC327TA before using Hesener's circuit on the 512-BC337BU and 512-BC327BU's that I have. They should be here in a couple of days or so. I can report what I find when they arrive.
512-BC32740TA & 512-BC33740TA readings
Here is what I got:
512-BC32740TA
hfe____________qty.
360 - 400----------30
401 - 415----------70
416 - 425----------65
426 - 500----------25
512-BC33740TA
hfe___________qty.
400 - 430---------50
431 - 460---------60
461 - 490---------40
491 - 600---------50
Measurements were taken at 71.5 degrees all in one sitting using Hesener's circuit - no fan or gloves, just handled them quickly. I will do more careful matching during the build. Most matches are between 410 - 435.
Parts were ordered from Mouser and sent from Mansfield, TX.
Here is what I got:
512-BC32740TA
hfe____________qty.
360 - 400----------30
401 - 415----------70
416 - 425----------65
426 - 500----------25
512-BC33740TA
hfe___________qty.
400 - 430---------50
431 - 460---------60
461 - 490---------40
491 - 600---------50
Measurements were taken at 71.5 degrees all in one sitting using Hesener's circuit - no fan or gloves, just handled them quickly. I will do more careful matching during the build. Most matches are between 410 - 435.
Parts were ordered from Mouser and sent from Mansfield, TX.
Indeed difficult to ship them when I haven't received them yet 
International shipment is very slow at the moment, and that will include my shipment to you. Most post small parcel were shipped on commercial airline, since most commercial airlines are shutdown, delivery time will certainly increase, think 'by boat' kind of delay. Over here everything (except the post service, grocery, drug store, etc) are shut down for at least three weeks. So expect delay. At least we can still take a walk outside. I'll do my best.
Thanks for your understanding and check this thread for updates.
SB
International shipment is very slow at the moment, and that will include my shipment to you. Most post small parcel were shipped on commercial airline, since most commercial airlines are shutdown, delivery time will certainly increase, think 'by boat' kind of delay. Over here everything (except the post service, grocery, drug store, etc) are shut down for at least three weeks. So expect delay. At least we can still take a walk outside. I'll do my best.Thanks for your understanding and check this thread for updates.
SB
That's not a valid excuse! You should have flow to pickup the pcbs yourself! I mean, I paid $5 US dollars for shipping. That should cover your flight to the pcb shop, the purchase of a face mask and sanitizer for the trip and treatment afterwards if the facemask and sanitizer don't work!
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