Re: Z-Wave RF range

[Joerg <notthisjoergsch@xxxxxxxxxxxxxxxxxxxxx>]

Robert L Bass wrote:

>>>Houston is trying to convince you that
>>>things running in the 900mHz band
>>>have an average range of 20-25 feet.
>>>That is total BS and he knows it.
>>
>>It sure will be more than 25ft but it won't
>>likely reach our garage ;-)
>
>
> That would depend on how many other nodes you were to use and their placement.  If Z-Wave passes my test (nodes about evenly spaced
> to reach all three wings of the house) I'll be adding lots more.  I have 55 switches, dimmers and fan controllers inside the house,
> about 10 more outside and about 20 outlets I want to control.
>

If it is required to install a reasonable spread of other modules acting
as repeaters then the manufacturers need to tell that to potential
customers in clear words. I hope they don't bury that in the fine print
since that would lead to lots of "It don't work" returns.

>
>>Just for the record I am not dissing Z-Wave
>>or RF in general here but I wanted to raise
>>a concern. After all, I work in the field of RF engineering ;-)
>
>
> I didn't get the impression you were being unfair.  It's Dave Houston's deliberate misrepresentations with which I took issue.
>
>
>>>>It's like with cars. A tire blow-out is considered
>>>>as something that can happen. An engine that
>>>>quits is, nowadays, considered something that's
>>>>not supposed to happen.
>
>
> Assuming the owner remembers to change the oil, that is true.  There was this beautiful Chevy conversion van I once owned, however,
> and... oh, well.  :(
>

Removing the engine from one of those doesn't look like fun. It's so
tight in there.

>
>>>Appliances fail.  Lights burn out.  HA
>>>components occasionally need service.
>>>The issue here isn't whether things can
>>>fail. The question raised is what is the
>>>range of Z-Wave, a 900mHz RF system.
>>>I say it's a good deal more than the 25-
>>>30 feet some have claimed.  Experience
>>>tells me that.
>>>
>>>If you're waiting until there are no problems, forget it.  You'll never get there.  Every industry always has problems.  I choose
>>>to work in this trade because I enjoy it.  It's also modestly remunerative.  :^)
>>>
>>
>>Good for you. I work in the med electronics biz and maybe that makes me a bit picky. Our stuff has to work. All the time, even
>>after having been smashed into an elevator door. A major conk-out can easily lead to a nasty lawsuit or at least cause some FDA
>>guys to waltz in there and fasten a gigantic padlock on the factory doors. It's happened.
>>
>>
>>>>>No problem.  I'll let you know how
>>>>>it works for me anyway.
>>>>
>>>>Yes, please let us all know.
>>>
>>>
>>>>>Many (most?) of those are non-towered
>>>>>anyway.  Some only have UNICOM
>>>>>service which is operated very sporadically.
>>>>>Some have nothing at all -- pilots simply
>>>>>"self announce" before they maneuver in
>>>>>the area.
>>>>
>>>>That's exactly how this airfield works. The
>>>>runway lights are "keyed on" by keying the
>>>>mike 4-5 times. They do that right over our
>>>>house and a 5W transmitter packs a punch
>>>>if it's only 250ft away :-(
>>
>>Don't we all play those games? Once I joked a bit after the gear was lowered "That didn't sound normal!". My wife told me never to
>>do that again. Well, after we had an engine out over the Atlantic I kind of don't do that anymore.
>
>
> The only engine failure I ever experienced was with my CFI flying right seat and my son in the back seat.  At first I thought he had
> done something so I was totally relaxed (a little annoyed, actually, because I didn't want him to scare my son) as I went through
> the engine failure checklist: applied full throttle and carb heat, pushed forward to put it in best glide speed, checked all the
> goodies while making a slow turn back toward a golf course we had just passed.  When I'd completed the check list I asked the CFI,
> "OK, now what?", expecting him to reach over and undo whatever he'd done to kill my engine.
>
> Instead he said, "I don't know.  This isn't a test."
>
> [me, silently: Aggggkkkkhhh!]
>
> Then he said, "Are you forgetting something?"
>
> I thought for a moment and then put the fear of God into my boy as I keyed the yoke button and said, "Mayday, mayday, mayday.  This
> is Cessna ######.  I have an engine failure and will attempt off airport landing approximately 18 miles West of Brainard Airport.  I
> am a white 172 with red lettering. I have three souls on board."
>
> In truth, young Joe thought we were pulling his leg all the way up to when Center replied, telling me to squawk 7700 which I had
> only simulated doing at first, thinking the CFI had been testing me.
>
> My wife won't even ride in anything that seats less than 100 pax but I love small airplanes.  BTW, there's a guy we know who claims
> (you'll love this one) that Boeing loaned him a brand new 737 so he could test his pet theory about a fatal airline accident.  He
> says he snap-rolled the 737 at 5000 AGL... and lived to tell about it.  The guy never flew anything bigger than a paper airplane, of
> course.  :^)
>

Ouch. There is another guy at the s.e.d. newsgroup who had to nail his
fully occupied Cessna down on a freeway.

On the AA flight we got a real VIP reception. All the fire engines and
ambulances Frankfurt could muster seemed to be there. And they cleared
the whole FRA airspace for us. Imagine that, it's a hub like Chicago.

>
>>>There's plenty of more noxious stuff
>>>than Visqueen to burn in a house.
>>
>>Sure, but why add to the mix if it isn't
>>necessary? I try to avoid plastics when
>>I can. And wood, because that stuff not
>>only burns but also rots.
>
>
> Plastic is pretty tough to avoid.  I'm replacing my roof at present.  The new method doesn't use tar any more.  It's a peel and
> stick layer of what looks like pantry shelf paper, except wider and heavier.
>

Our roofer offered that as well. After the down payment, of course,
because it would have cost more. I looked at it and decided to go with
the usual 30 pound felt double-layered. Not just because of price.
Someone from Sweden told me that builders over there are going back to
felt. Don't remenber the reason, maybe rot or mold underneath because it
doesn't breathe and moisture can condensate on the underside (that
touches the wood).

>
>>>What is it with California anyway?
>>>You guys have millions of geniuses
>>>working in Silicone Valley yet you
>>>hire moron ex-actors as governors.
>>>Oh, well.  At least this one can't
>>>become president.
>>
>>Not yet, and maybe he doesn't want to.
>
>
> He's inelligible.  He wasn't born in the USA.
>

There was a discussion to change that but that could take north of 200
years :-)

>
>>But he sure is a good governor IMHO.
>>I don't like his movies though. Not
>>because of his acting but because I
>>don't enjoy those kinds of movies at all.
>
>
> His movies are mostly just silly.  He's so wooden it becomes a sort of comedy.
>


We just don't like movies with violence in there. Ok, I confess, I do
like Westerns.

--
Regards, Joerg

http://www.analogconsultants.com