[RFI] Smoke Detectors Beeping

[kostas sv1dpi]

Change the wiring of smoke detectors with ftp (foiled twisted pair) 
cable. As Jim says in his paper, twisted pair cables are better 
protected by RF. Have in mind that UTP (unshielded twisted pair) is good 
(as twisted pair). There are UTP5, UTP6 and UTP7. Bigger number is 
better. Also FTP and SFTP (shielded foiled twisted pair). The best cable 
you can use is SFTP. I am sure that you will not have problems after 
replacing the cabling.

73 Kostas SV1DPI

Στις 28/7/2018 06:14, ο Dave Cole (NK7Z) έγραψε:
> Stan,
>
> Add a decent. (as high an impedance as you can build), choke at the 
> feedpoint of the antenna right after any impedance matching device, 
> then add another at the point where the coax enters your home.
>
> If you are still having issues, see if your alarm systems are tied 
> together to a central unit, you might want to look at that as well.
>
> Take a look at Jim's, (K9YC), papers on suppression using chokes. See:
>
> http://k9yc.com/publish.htm
>
> under "Hum, buzz, and RF Interference"...
>
> 73s and thanks,
> Dave (NK7Z/NNR0DC)
> https://www.nk7z.net
> ARRL Technical Specialist
>
> On 07/27/2018 10:49 AM, Stan Zawrotny wrote:
>> I have been troubled for quite some time with our smoke detectors
>> frequently beeping (two beeps) when I am working HF. It is worst on 
>> 80 and
>> 40, but also occurs frequently when I am on 15 and 20 meters. The 
>> beeping
>> will be intermittent at intervals of 1-3 minutes and will last for a 
>> couple
>> of minutes after I am through transmitting.
>>
>> I has happened with several rigs. Yaesu FTdx5000, Flex-6600M and Icom
>> IC-7300, at power ranging normally from 50-100 watts.
>>
>> Of course, the antenna system is likely the culprit. It consists of 
>> several
>> OCF dipoles: one 160-10 M and two 80-10 M. (I know OCF dipoles are 
>> bad for
>> RFI). All have 1:1 baluns at the antenna and at the shack.
>>
>> I have tried clip-on ferrite beads on the power leads of the smoke
>> detectors without luck.
>>
>> I just bought a DX Engineering Feedline Current Choke (DXE-FCC050H05-B)
>> that is supposed to suppress RFI on antenna leads. That is ineffective.
>>
>> I am now considering replacing the entire smoke detector system. We 
>> share a
>> house with my daughter and there are 9 units tied together in the 
>> system,
>> so the cost will not be small.
>>
>> Are there other solutions?
>>
>> Are there brands of smoke detectors that are less susceptible to RFI 
>> than
>> others.
>>
>> Any other thoughts?
>>
>> Stan
>> ___________________
>> Stan Zawrotny, K4SBZ
>> K4SBZ.Stan at Gmail.com
>>
>> Real radio bounces off the sky.
>> _______________________________________________
>> RFI mailing list
>> RFI at contesting.com
>> http://lists.contesting.com/mailman/listinfo/rfi
>>
> _______________________________________________
> RFI mailing list
> RFI at contesting.com
> http://lists.contesting.com/mailman/listinfo/rfi