FWIW, we use a Nest Protect here (hardwired into A/C, too) and haven't had problems with RFI. I imagine it'd be a different story if it didn't use Wi-Fi, though.
Speaking of Wi-Fi, our Ubiquiti access point required at least four Ethernet chokes, a third party PoE injector and CAT7 shielded cable to get the RFI down to an acceptable level. That was a fairly surprising thing to have happen but I guess PoE in general is well known to be really bad for RFI (and the limited antenna possibilities at the QTH I'm sure didn't help either). -Mooneer K6AQ On Sat, Oct 24, 2020 at 9:02 PM Mark Goldberg <marklgoldb...@gmail.com> wrote: > I have an older wired alarm system that uses serial data, and it is > indeed awful. The serial data is quite slow but it has no filtering. I > added an LC filter that works well enough to keep the RFI out of my > station, at least down to the level of what comes from my neighbors > and keeps my station from setting off the alarm system (most of the > time). > > At my son's house, he and neighbors have some SimpliSafe and other > wireless alarm systems and the HF Ham bands are wiped out by the RFI. > I have no idea what nominal frequency range or signalling they use. I > would expect for battery life they would not transmit often, but > whatever they do to create the RFI is continuous. > > I also have a hard wired smoke alarm from Kidde. That uses a DC > interconnect between units. I believe any unit that goes off pulls a > line up to about 9 V and they all go off. They are kind of cagey as to > exactly what the interconnect signal is though, so I may be a little > off. I have not detected any issues with RFI or susceptibility. Those > may indeed work for you. > > I do have a Spectrum Analyzer and multiple types of clamp on probes > and antennas but have not taken the time to do any quantitative > measurements of any of these. > > Having to tell the Fire Department that the fire alarm is false is not > a good thing. > > 73, > > Mark > W7MLG > > On Sat, Oct 24, 2020 at 7:38 PM Jim Brown <j...@audiosystemsgroup.com> > wrote: > > > > On 10/24/2020 6:53 PM, Harlan Sherriff via Elecraft wrote: > > > So, guess I’ll send these back and get some hardwired interconnected > units. > > > > That is probably a recipe for noise, radiated by that interconnected > > wiring. The security industry has long been notorious for EMC to and > > from their systems. WiFi interfacing should reduce both significantly, > > but before committing to anything, chat up engineers at the company > > about RFI. > > > > 73, Jim K9YC > > ______________________________________________________________ > > Elecraft mailing list > > Home: http://mailman.qth.net/mailman/listinfo/elecraft > > Help: http://mailman.qth.net/mmfaq.htm > > Post: mailto:Elecraft@mailman.qth.net > > > > This list hosted by: http://www.qsl.net > > Please help support this email list: http://www.qsl.net/donate.html > > Message delivered to marklgoldb...@gmail.com > ______________________________________________________________ > Elecraft mailing list > Home: http://mailman.qth.net/mailman/listinfo/elecraft > Help: http://mailman.qth.net/mmfaq.htm > Post: mailto:Elecraft@mailman.qth.net > > This list hosted by: http://www.qsl.net > Please help support this email list: http://www.qsl.net/donate.html > Message delivered to moon...@gmail.com ______________________________________________________________ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:Elecraft@mailman.qth.net This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html Message delivered to arch...@mail-archive.com
