really inexpensive field strength meter

Started by starshippe, August 15, 2013, 09:48:19 PM

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starshippe


   if u have found the hangar with the offending elt using a scanner, but u can't tell which of the dozen aircraft is guilty, this field strength meter will resolve ur problem.
   if u have a digital voltmeter and a diode, u r in business. just connect the diode across the input, hook up a short piece of wire, and set the meter to measure voltage.
   u can make it more sensitive by using a set of tv rabbit ears, and soldering the diode across the elements. then set the length of each element to 23 inches. also, a germanium diode such as a 1n34a will be more sensitive than a silicon diode. radio shack used to sell packs of ten, and they are available on line.
   u should be able to see voltage about 10 feet from the transmitter. as u move closer, the voltage will pick up respectably.
   a disadvantage is the sensitivity to any other radio signals in close proximity.
   other versions use a mechanical meter, some with tuned circuits and/or amplifiers to further improve sensitivity.

bill

vento

This is really interesting. Thanks for sharing.

JoeTomasone

Alternatively, remove the antenna from your handheld, and touch it to the ELT antenna of each aircraft.   You'll know when you have the right one.  :)

If need be (like if you receive a signal everywhere in the hangar), tune off frequency slightly.   


jeders

Quote from: JoeTomasone on August 19, 2013, 08:22:29 PM
Alternatively, remove the antenna from your handheld, and touch it to the ELT antenna of each aircraft.   You'll know when you have the right one.  :)

If need be (like if you receive a signal everywhere in the hangar), tune off frequency slightly.

And more inexpensive and hassle free than getting and carrying around a voltmeter.
If you are confident in you abilities and experience, whether someone else is impressed is irrelevant. - Eclipse