Electronics > RF, Microwave, Ham Radio

Impact of elevator on 14MHZ (and how to remove it)

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You should read up on them. Google "magnetic loop"

They have advantages and disadvantages. For receiving they sometimes can't be beat. They let you turn the loop and cancel out noise in their null.

One thing I would worry about in an apartment or indoors generally, another user had an experience with a loop in that transmitting created a field so strong I think it damaged neighbors electronics, living in an apartment building you have to be careful because your neighbors are only a few feet away above and below you.

If you put the loop outdoors - maybe on an arm extended out from a balcony it might look a bit strange but likely would be safer for nearby people and electronics. One person I know who uses a loop brings his loop antenna and his (battery operated) radio to a neighborhood park.

Also, capacitors need to sized in relation to the voltage you may have flying around the loop. The kinds of capacitors in radios vary in terms of their suitability and sometimes melt or arc over unexpectedly, and if that happened your radio's final would likely be toast in a second.

What I am saying is, do your research first and know what you are doing. Its not the kind of antenna you can just throw up and use without much thought as to what's happening there.

You should know, I am not a ham yet. I dont drive, dont own a car and need to get it together to get licensed, (basically swallow my pride and ask somebody to drive me or go into the city some evening by bus).  However, the info I am giving you here is accurate.

(I've lived most of my adult life in cities with world class public transpo. but don't live in one now. :o)

I am quite familiar with using mag loops to receive.  "They rock"   ;)


--- Quote from: mehdi on February 18, 2016, 08:27:07 pm ---
--- Quote from: uncle_bob on February 15, 2016, 05:13:44 pm ---Hi

One thing that has not (yet) been asked:

What brand (manufacturer) is the elevator? I'd hope that would be fairly obvious. In some countries it's not. The information all points to the local maintainer rather than to the manufacturer. If we get into any sort of analysis, it might be a useful thing to know.


--- End quote ---

The manufacturer of the motor is Gem (Italy)
Here's a picture:  http://i63.tinypic.com/23t0f4m.jpg
The controller unit is made by a local company (based on Atmel AT89C51)
By the way, the earth connection is not connected. So the next step is: I will first fix the earth connection, then if it didn't solve the problem, I will go for the ferrite beads and decoupling capacitors.

P.S: You were correct. I tried to become a friend with the support guy. At first he wasn't interested in my problem, but after showing my antenna and my test equipment and radios, he was fascinated and asking me all sorts of questions about Electronics and radios :)

--- End quote ---


Get the guy on your side and you will get this solved.

Actually it's a pretty good "life lesson". Making friends generally gets better results than yelling ...



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