Pages: [1]   Go Down

Author Topic: Suggestion on a cheap EMI detector  (Read 6477 times)

AA4HA

  • Member
  • Posts: 2689
Suggestion on a cheap EMI detector
« on: April 15, 2010, 05:51:14 AM »

A few years ago (ok, a long time ago) I had an idea to make an EMI/RFI detector for portable use. What I lit upon was to take the head out of an old tape-deck and feed the output into a very high gain op-amp circuit and then run that output to a earphone. The entire device was smaller than an Altoids tin and was powered off of a 9 volt battery.

When doing an EMI/RFI sweep of a building the tape head is very sensitive when placed in close proximity to the offending device. I could even put the tape head sensor near the breaker handle in a circuit box to find individual branch circuits where an offending device was attached to.

At one time the biggest source of RFI in a home was the television set. Now it is pretty much anything with a digital circuit and a circuit component that oscillates.

Just a tip,
Tisha Hayes, AA4HA
Logged
Ms. Tisha Hayes, AA4HA
Lookout Mountain, Alabama

KF5CZG

  • Member
  • Posts: 89
RE: Suggestion on a cheap EMI detector
« Reply #1 on: April 15, 2010, 05:56:31 PM »

Cool.  Sounds like a great sniffer.
Logged
Pages: [1]   Go Up