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Re: Blocking RF from intentional radiators

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>>>>> You still haven't answered my question.  What problem are you trying
>>>>> to solve?
>>>>
>>>> I want to disable the wireless control of the opener.  Jim's opener
>>>> has a FEATURE that allows this.  So, how do you retrofit that feature
>>>> to other openers, without requiring the opener to be replaced or the
>>>> owner/user to undertake some disassembly activity that can potentially
>>>> irreparably damage the opener?
>>>
>>> No, Don, that's "defining the solution space", not the problem.
>>>
>>> Is there a rash of garage break-ins by crooks running through codes on
>>> generic replacement remotes or something?
>>
>> I don't want to encourage a long, digressionary evaluation of what I'm
>> trying to do, why, etc.  Then, have the *ninnies* grumble because of the
>> wasted bandwidth -- for something THEY can't fathom or in which they have
>> no interest.
>
> Aw, Don, this is the INTERNET- where else are we gonna go?

(sigh)

>> "Why" invites alternatives that I'm smart enough to have already ruled
>> out. And, have no desire to feel the need to justify those reasons to the
>> ninnies.
>
> Well, that's nice and all, but how do you know for sure that all the
> alternatives you've ruled out are the only possible alternatives? I sure
> don't.

I'm willing to trust my appraisal of "the alternatives".  I surely wouldn't 
want to inconvenience the likes of Lasse by LISTING all of the things I've
considered!  And, the reasons why I've ruled them out...

>> I stated a clear problem.  I identified the constraints that govern the
>> solution.  The skill level, invertibility, cost constraints, etc.
>
> Trouble is it's way too broad. I mean, there are all sorts of ways for an
> unskilled individual to "blind" an RF receiver but which you use depends on
> the band, the signal strength at the receiver, the antenna placement, the
> weather...

That's why I posed a specific application instead of "how do I interfere with
RF reception".

> Knowing which to use is where the skill comes in.
>
>> If this is insufficient for folks to come up with a solution, then knowing
>> WHY won't help them solve THIS problem -- instead, it will encourage them
>> to try to solve some other, unrelated problem.
>
> Hell, there's an overload cutout on mine that auto-disables it if the motor
> draws too much current. A bolt stuck through the holes in the door and track
> works just fine to prevent unauthorized entry and harms nothing. If I want
> to open the door without using the remote I just pull the bolt out and hit
> the button.
>
> But that won't work for *all* GDOs.

I could flip the breaker and achieve a similar result.  Do we want to turn this
thread into a lengthy discussion of all the POSSIBLE ways to interfere with
the "remote" operation of the opener?  Or, do we want to look at the IMPLIED
mechanism by which I'm hoping it can be disabled?

>> If I told you I wanted a DSRV that could operate at depths of 50 fathoms
>> and had a single manipulator that had to have a range of extension of 0-5
>> inches and the capacity to support a 5 pound weight in atmosphere, would
>> you need to know if I was planning on using it to retrieve old cannon
>> balls from the sea floor vs. *stones*?
>
> See, I might suggest a magnet instead of a claw, but first you have to tell
> me what the cannon balls are made of.

And, if they aren't cannonballs but rocks, instead?

[Remember, we're on a budget not to type more characters than Lasse has the
patience to read!  :> ]

>> Sure, you might be able to come up with an alternative -- knowing the
>> intended application.
>>
>> Or, not.
>
> But you won't know until you ask.

But I've already explored the alternate solution spaces.  And, ruled those
options out.  It's easy to come up with a limitless menu of options if
you ignore ALL constraints.  Do I need "you guys" to determine that
the criteria I am applying are appropriate FOR MY APPLICATION?

I think its arrogant to presume that a poster doesn't understand their
own application domain.  And, expect them to EDUCATE you on it to "prove"
their throughness in analyzing the available options.

Then, *whine* when they type more than the THREE SENTENCES in the
original post!

Do you REALLY question every criteria/constraint your clients/employers
impose on you?  Do you wonder why you have to be at your desk certain
hours of the day?  Why the facility is located on the north side of the
street (which necessitates making a U-turn to enter the parking lot)
instead of the South?  etc.

Do you really think everyone else is incapable of coming to conclusions?

>> Please trust me to understand MY application(s).  If you want to solve a
>> DIFFERENT problem -- possibly related to garage door openers -- please
>> feel free to posit that and its criteria.
>
> Thing is, you haven't told us what the problem *is*. Per what you say below
> you're asking for a noninvasive reversible one-size-fits-all method for
> blinding *any* RF receiver that an untrained individual can implement
> reliably.

No.  I posed a specific case:
     How can I economically, simply and reversibly inhibit the RF link to a GDO?
I embelished this to show other reasons why similar things could be of
interest -- because folks couldn't relate to the simple, concise example that
I originally presented.  So they wouldn't fixate on "my" garage door opener
and the class of people in the neighborhood.  Or, *my* WiFi router. Or...

But, once you generalize, then folks complain that you've added far more
text to the description of the problem and confused them in the process.

I don't do RF.  Someone could easily and instructively have said:
     "You have to eliminate all means by which the radiated energy can
     find its way into the circuit.  These include radiated through open
     air, conducted through ungrounded surfaces, etc.  The sizes of any
     'vulnerable' openings are related to the fundamental frequency by the
     formula...  The field intensity falls off as..."

     "With these things in mind, for a GDO, the frequencies used are
     typically ... at power levels of ...  So, any opening larger
     than X needs to be obstructed and N layers of grounded shields
     need to surround the front end to ensure an attenuation below
     <whatever is typical for a GDO's receiver> at a distance of Y"
For someone "skilled in the art", this should be a piece of cake, right?
Sort of like asking me how quickly I have to clear the Rx holding register in
a UART given a particular operating bit rate and some number of competing
IRQ's at different service latencies.

> There ain't no such animal.
>
>> [Hey, maybe I'm not really interested in garage door openers but just use
>> them as a representative example of the type of electronics, frequencies,
>> power levels, convenience, etc. that *are* important to me!  ;)  ]
>
> Then you've opened the solution space even farther. Suppose you *really*
> want to disable the WiFi on your laptop without getting into the settings
> while still leaving the laptop usable standalone? First I need to know where
> the antenna(s) is/are, which I can't do without opening it up, and my
> solution is almost guaranteed NOT to work for your class-representative GDO.
> Nor are there any holes to stick a bolt through...

You'll note that I did NOT mention these examples in my OP!  I.e., I
made a deliberate effort to restrict the appication domain and the ensuing
discussion.

> So here are the solution parameters I can identify; noninvasively and
> reversibly prevent an RF receiver from seeing enough of an incoming signal
> to activate a programmed response without RF electronics or mechanical
> expertise.
>
> If that was a test question on a job application I'd apply elsewhere..

So, you wouldn't be hired at a garage door opener manufacturer because
you abstracted the question beyond what was ASKED!

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Blocking RF from intentional radiators Don Y <blockedofcourse@foo.invalid> - 2017-02-06 00:40 -0700
  Re: Blocking RF from intentional radiators whit3rd <whit3rd@gmail.com> - 2017-02-06 00:56 -0800
    Re: Blocking RF from intentional radiators Don Y <blockedofcourse@foo.invalid> - 2017-02-06 02:19 -0700
      Re: Blocking RF from intentional radiators Robert Baer <robertbaer@localnet.com> - 2017-02-08 20:22 -0800
  Re: Blocking RF from intentional radiators piglet <erichpwagner@hotmail.com> - 2017-02-06 11:57 +0000
    Re: Blocking RF from intentional radiators "Tim Williams" <tiwill@seventransistorlabs.com> - 2017-02-06 06:51 -0600
    Re: Blocking RF from intentional radiators Don Y <blockedofcourse@foo.invalid> - 2017-02-06 06:52 -0700
      Re: Blocking RF from intentional radiators Jim Thompson <To-Email-Use-The-Envelope-Icon@On-My-Web-Site.com> - 2017-02-06 07:55 -0700
        Re: Blocking RF from intentional radiators Don Y <blockedofcourse@foo.invalid> - 2017-02-06 12:38 -0700
          Re: Blocking RF from intentional radiators Tim Wescott <seemywebsite@myfooter.really> - 2017-02-06 14:18 -0600
            Re: Blocking RF from intentional radiators Don Y <blockedofcourse@foo.invalid> - 2017-02-06 14:39 -0700
              Re: Blocking RF from intentional radiators Jon Elson <jmelson@wustl.edu> - 2017-02-06 17:10 -0600
                Re: Blocking RF from intentional radiators Don Y <blockedofcourse@foo.invalid> - 2017-02-06 17:06 -0700
                Re: Blocking RF from intentional radiators Jasen Betts <jasen@xnet.co.nz> - 2017-02-07 04:12 +0000
              Re: Blocking RF from intentional radiators Jasen Betts <jasen@xnet.co.nz> - 2017-02-07 04:05 +0000
          Re: Blocking RF from intentional radiators Jim Thompson <To-Email-Use-The-Envelope-Icon@On-My-Web-Site.com> - 2017-02-06 14:56 -0700
            Re: Blocking RF from intentional radiators Don Y <blockedofcourse@foo.invalid> - 2017-02-06 15:18 -0700
        Re: Blocking RF from intentional radiators Robert Baer <robertbaer@localnet.com> - 2017-02-08 20:41 -0800
      Re: Blocking RF from intentional radiators Robert Baer <robertbaer@localnet.com> - 2017-02-08 20:32 -0800
    Re: Blocking RF from intentional radiators Phil Allison <pallison49@gmail.com> - 2017-02-06 06:39 -0800
  Re: Blocking RF from intentional radiators John Larkin <jjlarkin@highlandtechnology.com> - 2017-02-06 08:28 -0800
  Re: Blocking RF from intentional radiators Jeff Liebermann <jeffl@cruzio.com> - 2017-02-06 09:23 -0800
    Re: Blocking RF from intentional radiators Lasse Langwadt Christensen <langwadt@fonz.dk> - 2017-02-06 09:30 -0800
    Re: Blocking RF from intentional radiators Don Y <blockedofcourse@foo.invalid> - 2017-02-06 11:52 -0700
      Re: Blocking RF from intentional radiators Jeff Liebermann <jeffl@cruzio.com> - 2017-02-06 11:31 -0800
        Re: Blocking RF from intentional radiators Don Y <blockedofcourse@foo.invalid> - 2017-02-06 12:49 -0700
          Re: Blocking RF from intentional radiators John S <Sophi.2@invalid.org> - 2017-02-06 14:07 -0600
          Re: Blocking RF from intentional radiators "nuny@bid.nes" <Alien8752@gmail.com> - 2017-02-06 12:09 -0800
            Re: Blocking RF from intentional radiators Don Y <blockedofcourse@foo.invalid> - 2017-02-06 13:37 -0700
              Re: Blocking RF from intentional radiators "nuny@bid.nes" <Alien8752@gmail.com> - 2017-02-06 14:35 -0800
                Re: Blocking RF from intentional radiators Don Y <blockedofcourse@foo.invalid> - 2017-02-06 15:59 -0700
          Re: Blocking RF from intentional radiators Jeff Liebermann <jeffl@cruzio.com> - 2017-02-06 17:56 -0800
      Re: Blocking RF from intentional radiators George Herold <gherold@teachspin.com> - 2017-02-06 12:03 -0800
        Re: Blocking RF from intentional radiators Don Y <blockedofcourse@foo.invalid> - 2017-02-06 13:31 -0700
          Re: Blocking RF from intentional radiators George Herold <gherold@teachspin.com> - 2017-02-06 13:29 -0800
            Re: Blocking RF from intentional radiators Lasse Langwadt Christensen <langwadt@fonz.dk> - 2017-02-06 13:32 -0800
            Re: Blocking RF from intentional radiators Don Y <blockedofcourse@foo.invalid> - 2017-02-06 15:01 -0700
              Re: Blocking RF from intentional radiators Jim Thompson <To-Email-Use-The-Envelope-Icon@On-My-Web-Site.com> - 2017-02-06 15:07 -0700
                Re: Blocking RF from intentional radiators Don Y <blockedofcourse@foo.invalid> - 2017-02-06 15:13 -0700
                Re: Blocking RF from intentional radiators Lasse Langwadt Christensen <langwadt@fonz.dk> - 2017-02-06 14:28 -0800
                Re: Blocking RF from intentional radiators Don Y <blockedofcourse@foo.invalid> - 2017-02-06 15:31 -0700
                Re: Blocking RF from intentional radiators Jim Thompson <To-Email-Use-The-Envelope-Icon@On-My-Web-Site.com> - 2017-02-06 15:59 -0700
                Re: Blocking RF from intentional radiators Don Y <blockedofcourse@foo.invalid> - 2017-02-06 17:08 -0700
                Re: Blocking RF from intentional radiators pcdhobbs@gmail.com - 2017-02-08 16:36 -0800
                Re: Blocking RF from intentional radiators Clifford Heath <no.spam@please.net> - 2017-02-07 10:26 +1100
      Re: Blocking RF from intentional radiators whit3rd <whit3rd@gmail.com> - 2017-02-06 13:05 -0800
        Re: Blocking RF from intentional radiators Don Y <blockedofcourse@foo.invalid> - 2017-02-06 14:22 -0700
          Re: Blocking RF from intentional radiators kevin93 <kevin@whitedigs.com> - 2017-02-06 13:39 -0800
            Re: Blocking RF from intentional radiators Don Y <blockedofcourse@foo.invalid> - 2017-02-06 15:12 -0700
          Re: Blocking RF from intentional radiators whit3rd <whit3rd@gmail.com> - 2017-02-06 14:43 -0800
            Re: Blocking RF from intentional radiators "nuny@bid.nes" <Alien8752@gmail.com> - 2017-02-06 16:29 -0800
      Re: Blocking RF from intentional radiators Jasen Betts <jasen@xnet.co.nz> - 2017-02-07 04:19 +0000

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