[Lowfer] LowFER, HiFER signals.

[craig wasson]

That would be helpful.  It is always good to know what various signals you
hear might be coming from.


FYI - I wear Widex hearing aids (one in each ear) that communicate with
each other at 10.6 MHz with a power of around 25 picowatts.   They each
compare audio from both ears and do signal processing so they can do things
like feedback suppression and providing directional reception.  The specs
claim a radiated signal strength of -54uA/m @ 10 m although if you move
them more than a 2 feet apart they seem to lose signal.  I wonder about
that signal strength they claim - I wonder if they meant -54dbmw??   Or
were they trying to report microvolts per meter?   I suppose microAmps per
meter makes sense assuming you know the impedance of the antenna or space.

They also have a bluetooth adapter that injects audio from a device with a
loop antenna you wear around your neck - also at 10.6 MHz.  Again -  the
range of that seems to be just a foot or two at most.  I have never seen
these signals show up on my SDR-IQ but I believe the signals are fairly
wideband.  As I recall the data rate may be a few hundred kb/s

Also - at my home I have a Ted5000 system that monitors power utilization
and reports to a wall-wart web server using PLC.  The clamp-on sensors (my
system has 4 of them) each send an update (bpsk I believe) at 125KHz about
once every 2 or 3 seconds.  These show up readily on my SDR-IQ as you can
see on a snip from my SpectraVue display.   You can see what they report at
http://mb.wasson.com.

I also have 4 Enphase grid tie inverters that monitor output from my solar
panels.  These each send an update on 144KHz about once every 5 minutes.
You can also see those signals on the screen shot below.  You can see what
kind of data they report at:

https://enlighten.enphaseenergy.com/public/systems/RkDA152356

I thought some might find this interesting - especially if they have seen
similar signals and wondered what they were.  Luckily none of these systems
interfere with frequencies I regularly monitor.

Thanks - Craig - N6IO



On Sun, Jun 18, 2017 at 9:04 PM, KD7JYK DM09 <kd7jyk at earthlink.net> wrote:

> I've recently scrounged two consumer devices that may create/add to the
> signals/interference heard on 100 KHz and 13,560 KHz.
>
> One is a signalling device for the hard-of-hearing that operates at 100 KHz
> and uses household wiring as the antenna, the other, the Wallyhome
> household
> monitoring system that claims to operate at 27,120 KHz, but in fact is
> type-accepted for, and operates on 13,560 KHz.
>
> I'll fire the systems up and record what signals I can from them in various
> modes and offer the recordings to those that would like to hear them.
>
> Kurt
>
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