B&K had been around since the 1950s, but my personal experience with them was in school in the 1970s-80s. They are based in CA. Protek began in the mid 1990s, I know little or have experience with them, as they are relatively younger and based in NJ. They are both reputable, but I would rate B&K higher; it has weathered many economic storms and is still around.
However, both are less OEM or factories for equipment, I don't know if they do any design of their own, but much of their equipment come from ODM or OEM. Some are fairly obvious, some are not.
In the 1980s, BK sold analog oscilloscopes made by Kenwood, still known as Trio in Asia, then an upcoming Japanese brand that is now well established as a brand name, Kenwood gear is sold mostly in Asia as top brand.
My experience is BK knows how to choose ODM, so often its a marker of a good upstart. For example, these LCR meters, both branded by Agilent and BK of another ODM:
![](http://www.bkprecision.com/products/photos/intro/879_intro.jpg)
![](http://cp.home.agilent.com/upload/cmc_upload/U1731A_front.jpg)
I am glad they have a good reputation. All I have used is Agilent and Tektronix in college. I hadn't heard about most of these companies till I started reading this blog a few months ago.
Out of curiosity, what about some other companies. I have seen scopes, multimeters, and power supplies by BK Precision and PtoTek. I first saw these at a local electronics store. What kind of quality/reputation do these companies have?