Same how shoals of fish or flocks of birds move synchronously. There are some very simple rules having to do with keeping distance to your neighbor. No secrets here.
Jan
Mark what is the reason to buy from Rochester when others offer the same part for less?
Jan
Keantoken, you may want to compare BC32xx with BC547/557. They are typically rated as "B" gain class, but they often have a gain of 400:1. On occasion, they and BC550/560 low noise types are offered with a "C" rating, but that needs luck to be found. Do try at buerklin.com, they are not cheap but are reliable, been buying from them since 1975.
I use the BC3x7 and BC5xx almost constantly, unless I need high voltage transistors. The BC3x7-40 are sometimes useful for their low Rb, low quasi-saturation, high SOA, and high speed (if you buy from the right factory).
Keantoken, I don't know if you know this historic detail - in their day, Motorola used to sell BC651, possibly one of the lowest noise transistors ever. It had no PNP complement. And it was limited to 30V.
They also used to produce BD539/540, very similar to the standard BD 139/140, with slightly less power dissipiation capabilities, but running not at 80V but at 100V. A very fine device.
Unfortunately, both are now long gone. A pity.
They also used to produce BD539/540, very similar to the standard BD 139/140, with slightly less power dissipiation capabilities, but running not at 80V but at 100V. A very fine device.
Unfortunately, both are now long gone. A pity.
I'm sure you could list several; the one that often convinces me is: large batch orders. When nobody else sells part P and I order 100 pieces from distributor D, I often purchase additional devices at the same time, even if they are available elsewhere, even if the price is a few percent higher. This helps overcome the minimum order-size hurdle (often $50 or $100), and larger orders usually have substantially lower shipping costs per piece. The more you spend the more you save.
Here's an example. I really wanted the "F" (highest hFE) bin of 2SC3503 and 2SA1388, which are moderately hard to find. I topped up the order with other device types, some of which are available in many places and perhaps even an ooch tad bit cheaper elsewhere. But in my opinion it made good sense to batch the order and buy them here. Other people may have other opinions, of course. {happy note: the price of the F grade parts has fallen since 2014! Woo and hoo.}
_
Attachments
We use Rochester, I think they are a little more concerned with providing genuine product than others. The ADI parts at Rochester are directly from us, when it becomes uneconomical to support a part they provide a useful service.
Rochester is the place manufacturers can send customers who need MRO (Maintenance Repair Operations) parts that have been discontinued. So Rochester gets special pricing at the end of production as there are costs with keeping inventory particularly for parts that don't eventually sell. (Supposedly sometimes they get end of run leftovers for free.)
So it works out for almost everyone except those who really wait too long.
Now Jan being Dutch considers monetary cost first. Some of us consider our time, effort and reliability part of the cost.
Well the example price table I commented on showed genuine Fairchild parts 1-off for (iirc) 5 ct from one distributor, and 2000-off from Rochester for 7 ct each.
I thought my question was a logical one. YMMV.
Jan
Intermission.
Update on test and measurment: DAVADA has produced his own ultra low thd oscillator and has also been improving my ShibaSoku AD725D analyzer: Here is what I got from him yesterday......
Can measure accurately to -140dBV THD; -121dBV THD+N.
Here is screen data for analyzer at monitor port: FS @ 0dBV is -110dBV or .0003% FS
kuddo's goes to David in Canada!
SOTA
THx-RNMarsh
Update on test and measurment: DAVADA has produced his own ultra low thd oscillator and has also been improving my ShibaSoku AD725D analyzer: Here is what I got from him yesterday......
Can measure accurately to -140dBV THD; -121dBV THD+N.
Here is screen data for analyzer at monitor port: FS @ 0dBV is -110dBV or .0003% FS
kuddo's goes to David in Canada!
SOTA
THx-RNMarsh
Last edited:
And I would suspect the 5 cent'rs were fake or another brand. For two cents I would not risk it.
Just went back and looked. The cheap guys I saw are not an authorized distributor and deal in secondary markets.
BTY I have a great deal for you on a share in a bridge in Brooklyn, only E90!
Last edited:
I think Jan is talking about the attachment to post 70999, reproduced below (diyAudio's servers are "performing nightly maintenance" and won't let me attach images the normal way, grrr
Bristol's parts ARE cheaper. But what does that gold star mean? A couple more clicks gives the answer:
Last edited:
I think Jan is talking about the attachment to post 70999, reproduced below (diyAudio's servers are "performing nightly maintenance" and won't let me attach images the normal way, grrr
Bristol's parts ARE cheaper. But what does that gold star mean? A couple more clicks gives the answer:
No that wasn't it, I'm not THAT dense -)
But Ed had his joke, so let it go.
Jan
Yes you are right. But later part is still interesting where fish lined up head to tail. There was scientific explanation given probably in BBC documentary on how birds and fish manage that without collision. Birds.
Regards.
- Status
- Not open for further replies.