Viewing posts for the category SED

Random resources from my Usenet posts on sci.electronics.design

Sometimes it's useful to add supporting documents, schematics, scope photos, simulations or other things to Usenet posts.  By popular request I've added links to some of these, in no particular order.

How To Read SED: Archive Sites and Newsfeeds

One of the nice things about sci.electronics.design is that it's widely redistributed by archive sites, some of which you can also use for posting, which is good since they made such a hash of the new Google Groups one.

Some examples:
electronics-related

Cascode Enhancement pHEMT Photodiode Preamp

This is pretty small, because it has to be--those are microwave transistors, and will oscillate at the slightest provocation. The axial resistors and TO-92 parts are all for biasing---the actual amplifier is the part between the output coupling cap (the small orange thing in the middle) and the photodiode, which is the white square with the black middle at the right.

Transistor Tester for laser noise canceller

As discussed in medium-gory detail in this paper, laser noise cancellers can let you do shot-noise limited measurements at baseband with lasers that are as much as 70 dB noisier than that.