Hardening a simple op-amp circuit against EMI

Mar 17, 2009 88 Replies

Slowman's ignorance is pheeeeeee-nominal ;-)

[snip]

...Jim Thompson

-- | James E.Thompson, P.E. | mens | | Analog Innovations, Inc. | et | | Analog/Mixed-Signal ASIC's and Discrete Systems | manus | | Phoenix, Arizona 85048 Skype: Contacts Only | | | Voice:(480)460-2350 Fax: Available upon request | Brass Rat | | E-mail Icon at

formatting link
| 1962 | How severe can senility be? Just check out Slowman.

I use a nice little foxhunt sniffer made by VK3YNG which is remarkable for the incredible dynamic range in its front-end (quite a sensitive lo-noise receiver, but you can still DF when you're standing on 100W of RF transmitter, it doesn't swamp).

Anyhow, he found out the hard way that a commonly recommended decoupling method, namely a small cap closely paralleled with a larger one, often causes major problems when the small C resonates with the inductance of the larger one.

... just one case in point.

If anyone has an idea how to build a front-end like these have now that the dual-gate GaAs FET is unobtainium, I'd like to hear it.

Clifford Heath.

Speaking for yourself i see. .

Sure. I don't know a lot of things that Jim Thompson believes to be true. The ignorance of the real world invoved is entirely Jim's.

-- Bill Sloman, Nijmegen

Colman's mustard tins. I made an arc lamp out of one once.

Cheers

Phil Hobbs

Dr Philip C D Hobbs Principal ElectroOptical Innovations 55 Orchard Rd Briarcliff Manor NY 10510 845-480-2058 hobbs at electrooptical dot net http://electrooptical.net

Altoids, tobacco tins (I used to smoke a pipe ;-), all kinds of useful packaging out there.

...Jim Thompson

| James E.Thompson, P.E. | mens | | Analog Innovations, Inc. | et | | Analog/Mixed-Signal ASIC\'s and Discrete Systems | manus | | Phoenix, Arizona 85048 Skype: Contacts Only | | | Voice:(480)460-2350 Fax: Available upon request | Brass Rat | | E-mail Icon at http://www.analog-innovations.com | 1962 | I love to cook with wine Sometimes I even put it in the food

You can build elaborate structures from bits of copperclad FR4 and solder.

My grand-dad used to smoke cigars and gave me the cigar boxes, and I'd store stuff in them or build electronics in them. Cigar boxes are great.

That would be cool: a cigar box oscilloscope.

John

Nice.

The Altoids secret is out. Even round tins:

formatting link

Cheers, James Arthur

A fat-free low-carb receiver. Now that's progress :-)

Regards, Joerg http://www.analogconsultants.com/ "gmail" domain blocked because of excessive spam. Use another domain or send PM.

Join the Discussion

Have something to add? Share your thoughts — no account required.

Didn't find your answer?

Ask the community — no account required