annoying problem

I was wondering if i can cure an annoying problem when I am sending  cw on the hf bands above 15 meters.
 I have a small mini beam on the roof and my shack is directly under it. When I work the bands above 15 meters my smoke alarm beeps. Its in the hall between the bedrooms, so don't want to move it.
  Is there a way I can filter this problem without moving the smoke detector?
 Dumb question, but hate to move the detector.. but will , if I have to....

Don...w2xb  

[Jim Wiley]

If it is a wired-in smoke detector, try putting a .01 uFd 1400-volt "AC
rated" cap directly across 120-volt AC power leads.  If that isn't
enough, then try a capacitor the between (across) the wire, if there is
one,  that connects it to the other detectors and the AC neutral lead.  
If the unit is battery powered, try a .01 uFd 600 V cap across the
detection chamber.  That may work, but if not, get used to the idea of
having to move it.  Always test and verify proper operation of  the unit
by blowing actual smoke from burning wood matches into the unit after
making any modifications of this nature.  Pressing the "test" button is
not enough - use actual smoke.


- Jim, KL7CC


On 2/1/2013 7:48 AM, [hidden email] wrote:

> I was wondering if i can cure an annoying problem when I am sending  cw on
> the hf bands above 15 meters.
>   I have a small mini beam on the roof and my shack is directly under it.
> When I work the bands above 15 meters my smoke alarm beeps. Its in the hall
> between the bedrooms, so don't want to move it.
>    Is there a way I can filter this problem without moving the smoke
> detector?
>   Dumb question, but hate to move the detector.. but will , if I have to....
>
> Don...w2xb
>
>
>
> --
> View this message in context: http://elecraft.365791.n2.nabble.com/annoying-problem-tp7569472.html
> Sent from the Elecraft mailing list archive at Nabble.com.
> ______________________________________________________________
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>
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> Please help support this email list: http://www.qsl.net/donate.html
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[Richard Fjeld]

I will be interested in what you folks come up with.  One night, the band was open late and I was working 5 watts QRP CW on 20 meters using my tri-band beam.  The smoke detector went off, woke my wife and she panicked.  Ham radio was not popular in our house.

I later tuned up my 80 meter loop and could go 100 watts without setting it off using the same frequency.  The loop is fed with open wire.  The beam has a balun and is fed with coax. I always have a low pass filter in line.

I later bought a MFJ-915 RF Line Isolator and installed it on the coax to the beam.  So far, so good.  Then again, direction of the beam could be a factor.

Rich, n0ce
  ----- Original Message -----
  From: Jim Wiley
  To: [hidden email]
  Cc: [hidden email]
  Sent: Friday, February 01, 2013 11:40 AM
  Subject: Re: [Elecraft] annoying problem


  If it is a wired-in smoke detector, try putting a .01 uFd 1400-volt "AC
  rated" cap directly across 120-volt AC power leads.  If that isn't
  enough, then try a capacitor the between (across) the wire, if there is
  one,  that connects it to the other detectors and the AC neutral lead.  
  If the unit is battery powered, try a .01 uFd 600 V cap across the
  detection chamber.  That may work, but if not, get used to the idea of
  having to move it.  Always test and verify proper operation of  the unit
  by blowing actual smoke from burning wood matches into the unit after
  making any modifications of this nature.  Pressing the "test" button is
  not enough - use actual smoke.


  - Jim, KL7CC


  On 2/1/2013 7:48 AM, [hidden email] wrote:
  > I was wondering if i can cure an annoying problem when I am sending  cw on
  > the hf bands above 15 meters.
  >   I have a small mini beam on the roof and my shack is directly under it.
  > When I work the bands above 15 meters my smoke alarm beeps. Its in the hall
  > between the bedrooms, so don't want to move it.
  >    Is there a way I can filter this problem without moving the smoke
  > detector?
  >   Dumb question, but hate to move the detector.. but will , if I have to....
  >
  > Don...w2xb
  >
  >
  >
  > --
  > View this message in context: http://elecraft.365791.n2.nabble.com/annoying-problem-tp7569472.html
  > Sent from the Elecraft mailing list archive at Nabble.com.
  > ______________________________________________________________
  > Elecraft mailing list
  > Home: http://mailman.qth.net/mailman/listinfo/elecraft
  > Help: http://mailman.qth.net/mmfaq.htm
  > Post: mailto:[hidden email]
  >
  > This list hosted by: http://www.qsl.net
  > Please help support this email list: http://www.qsl.net/donate.html
  >

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If Jim's ideas don't work  you could simply try another detector of a
different brand.  Susceptibility to RF varies in unpredictable ways and
that is an easier solution than moving the detector (move it where?  
Would it actually help?).

Another approach, if it is a 'wired-in' detector, is to replace it with
a battery-only detector or, easier yet, just unplug the AC wiring
connector and let it run on battery only as a test to see if that cures
the susceptibility problem.  If it does cure the problem you would
probably need to replace the detector with a battery-only model which
would probably run for a lot longer between battery changes because the
wired-in type, when operating on battery only, can use up the battery
pretty fast.  If your detector is interconnected with other detectors so
that they all sound the alarm if any one of them senses smoke then going
battery only will defeat that feature and only you can decide if that is
a prudent thing to do and in accordance with codes ( In my house all of
my detectors are easily heard from all rooms).

Don K7FJ



On 2/1/2013 9:40 AM, Jim Wiley wrote:

> If it is a wired-in smoke detector, try putting a .01 uFd 1400-volt
> "AC rated" cap directly across 120-volt AC power leads.  If that isn't
> enough, then try a capacitor the between (across) the wire, if there
> is one,  that connects it to the other detectors and the AC neutral
> lead.  If the unit is battery powered, try a .01 uFd 600 V cap across
> the detection chamber.  That may work, but if not, get used to the
> idea of having to move it.  Always test and verify proper operation
> of  the unit by blowing actual smoke from burning wood matches into
> the unit after making any modifications of this nature.  Pressing the
> "test" button is not enough - use actual smoke.
>
>
> - Jim, KL7CC

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[Vic Rosenthal]

If the smoke detector is wired to the AC line, wrapping as many turns of the ac wiring as
possible around a ferrite toroid or rod should cure it. The little Radio Shack split
toroids sold for this purpose work. Or you could replace it with a battery-powered model.
If you already have a battery type, try this: cover the entire unit with aluminum,
punching holes everywhere that there are openings in the plastic of the unit. I had to do
this with a battery powered CO detector.

On 2/1/2013 8:48 AM, [hidden email] wrote:

> I was wondering if i can cure an annoying problem when I am sending  cw on
> the hf bands above 15 meters.
>   I have a small mini beam on the roof and my shack is directly under it.
> When I work the bands above 15 meters my smoke alarm beeps. Its in the hall
> between the bedrooms, so don't want to move it.
>    Is there a way I can filter this problem without moving the smoke
> detector?
>   Dumb question, but hate to move the detector.. but will , if I have to....
>
> Don...w2xb

--
Vic, K2VCO
Fresno CA
http://www.qsl.net/k2vco/

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[aj4tf]

I recently installed a CO alarm (required by code) and I observed a sensitivity to 40m transmissions.  It only occurs when I am about around 50W... the alarm goes off for a few seconds.  My antenna (dipole cut for 80m with a tuner) is on the outside of the house right now, but I have plans to move it out to the trees someday.  Since the alarm is the plug-in type, it won't be easy to install an AC rated cap across the line (although I guess I can put it in the outlet box).  

I have two solutions for this problem at the moment:

1) Only work 40m when the XYL is not home
2) Eventually get the antenna away from the house.

73, de AJ4TF