>>Are they supposed to chirp when another detector is removed or disabled?
They didn't chirp because they were removed. They were chirping because of
the RFI.
>>Does this mean they are in constant or periodic communications with one
another?
When one detector has an "event," it communicates with the entire network.
This is normal.
>>Is more than one frequency being used to intercommunicate between
detectors?
They only use one frequency.
>>Do they have an internal or external antenna on the units?
There is no visible antenna.
>>Have you contacted the vendor about this RFI?
I emailed the manufacturer, but they did not respond.
>>You have a somewhat unusual configuration compared to most that just
install battery operated, independent units.
Actually not. Wireless smoke detector systems are very common. If one
detector alerts, it alerts all detectors throughout the house. Each unit is
battery operated. But independent units are not installed in modern homes
any more.
___________________
Stan Zawrotny, K4SBZ
(850) 893-5003 (h) (850) 590-6617 (m)
K4SBZ.Stan@Gmail.com
Real radio bounces off the sky.
On Mon, Aug 17, 2015 at 4:32 PM, EDWARDS, EDDIE J <eedwards@oppd.com> wrote:
> " I disconnected the smoke detector in my office and the smoke detector in
> the foyer began to chirp. Because they are RF connected, another one in a
> distant part of the house also chirps."
> ...and...
> "433.93 MHz is one frequency used by smoke detectors."
>
> Are they supposed to chirp when another detector is removed or disabled?
>
> Does this mean they are in constant or periodic communications with one
> another?
>
> Is more than one frequency being used to intercommunicate between
> detectors?
>
> Do they have an internal or external antenna on the units?
>
> Have you contacted the vendor about this RFI?
>
> You have a somewhat unusual configuration compared to most that just
> install battery operated, independent units.
>
> 73, de ed -K0iL
>
> -----Original Message-----
> From: RFI [mailto:rfi-bounces@contesting.com] On Behalf Of Stan Zawrotny
> Sent: Monday, August 17, 2015 2:17 PM
> To: RFI@contesting.com
> Subject: [RFI] RFI With Smoke Detectors
>
> External Email Notice Think before you click! Email sent from
> rfi-bounces@contesting.com
>
> I have an RFI problem with my smoke detectors. The house has USI Electric
> Inc. Model USI 1208 smoke detectors installed throughout. Mostly when I
> operate on 40 meters, but also on 80, 15 and occasionally on 20 (not
> often), the smoke detector in my office where my FTdx5000 is located will
> chirp intermittently. It doesn’t start right away and will sometimes pause
> for long periods of time.
>
>
>
> 433.93 MHz is one frequency used by smoke detectors. It is the 60th
> harmonic of 7.232 MHz, a 40 M SSB frequency. The chirping will occur when I
> am operating as low as the RTTY band (7.025 – 7.125).
>
>
>
> I have tried installing toroids from a Polomar “RFI kit” without luck. I
> also installed an MFJ-704 low-pass filter in the antenna line, also with no
> results.
>
>
>
> I disconnected the smoke detector in my office and the smoke detector in
> the foyer began to chirp. Because they are RF connected, another one in a
> distant part of the house also chirps.
>
>
>
> I suspect that the close proximity of the rig to the smoke detectors just
> overpowers the toroids and that enough RF gets out from the transmitter and
> the short coax to negate the effectiveness of the low-pass filter.
>
>
>
> Is there anything else that I can do so that I can operate on 40 meters
> without upsetting the family?
> ___________________
> Stan Zawrotny, K4SBZ
> K4SBZ.Stan@Gmail.com
> _______________________________________________
> RFI mailing list
> RFI@contesting.com
> http://lists.contesting.com/mailman/listinfo/rfi
>
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