On 7/26/2014 6:15 AM, Lostgallifreyan wrote:
Jeff Liebermann wrote in
:

Passive repeaters do not work well. I can go through the calculations
for you but basically, you get approximately twice the path loss with
a passive repeater, as you would with a direct path. I can grind the
numbers for you if you want later (I'm giving a talk tomorrow and need
to get some sleep).


No need, but thankyou. I read about them a bit. I get the idea that they're
huge, totally impractical as a spot fix for a few rooms in a basement flat.

What is there to keep the amplifier from amplifying the "mush"?

Plenty. The mush is very localised, some widget (likely a wireless net box
or router) in the upstairs flat, it is not detectable beyond a quarter of the
distance to my outside antenna. Hence, wondering if a tiny boost and an
indoor dipole might be enough to overcome the immediate locality without
annoying the neighbours. See, if that mush does not reach the outdoor antenna
in any measurable degree, it seemed to follow that a tiny boost to adequate
levels might also fail to reach that outdoor antenna, and thus feedback might
be avoided, as well as unwanted transmission strength beyond my boundaries.
Purely speculative, but it seems logical enough to me...


If the box is putting out that much interference, there's a good chance
it has a problem (and may be operating illegally). I would think
correcting the problem at the source would be the better option.

--
==================
Remove the "x" from my email address
Jerry, AI0K

==================

Jerry Stuckle wrote in news:lr0908$usv$1@dont-
email.me:

If the box is putting out that much interference, there's a good chance
it has a problem (and may be operating illegally). I would think
correcting the problem at the source would be the better option.


Nope. It's one of those consumer widgets, one o millions, that have a
disclaimer saying that some limited interference must be accepted. Knowing
this, it isn't even worth trying to police the issue, and probably impossible
anyway. Computer based stuff just does this to us, there's no stuffing THAT
genie back in the bottle now.

On 7/26/2014 10:02 AM, Lostgallifreyan wrote:
Jerry Stuckle wrote in news:lr0908$usv$1@dont-
email.me:

If the box is putting out that much interference, there's a good chance
it has a problem (and may be operating illegally). I would think
correcting the problem at the source would be the better option.


Nope. It's one of those consumer widgets, one o millions, that have a
disclaimer saying that some limited interference must be accepted. Knowing
this, it isn't even worth trying to police the issue, and probably impossible
anyway. Computer based stuff just does this to us, there's no stuffing THAT
genie back in the bottle now.


That does not mean it's not operating illegally. Even with such a tag,
it can be emitting a signal illegally.

ALL potential sources of RF have limits on their emissions. Exceed
those limits and they are not operating legally. It may be due to
shoddy workmanship or a problem with the device itself.

--
==================
Remove the "x" from my email address
Jerry Stuckle

==================

Jerry Stuckle wrote in news:lr0d4e$spo$1@dont-
email.me:

That does not mean it's not operating illegally. Even with such a tag,
it can be emitting a signal illegally.

ALL potential sources of RF have limits on their emissions. Exceed
those limits and they are not operating legally. It may be due to
shoddy workmanship or a problem with the device itself.


Could be so, but like weed-smoking, popular round here, though I haven't done
it myself for at least twenty years and do not like it, is a live-and-let-
live thing, not a call-the-police thing. Also, if I start shouting about a
small bit of interference, people might start shouting about not liking my
solar panels outside the house looking (to their eyes) unacceptably ugly,
etc...

Also, the cost of the expert witness to prove it in court is a cost so
extreme in proportion to the problem that I won't consider it viable.

I suspect it's well within limits actually, no worse than half the small
collection of stuff I have like mice and keyboards emit. It's just what was
left after I'd turned off all I could control, in a basement that very little
external RF penetrates into anyway. Hence me steering the discussion back to
the notion of a gentle boost for the immediate locality.

On Sat, 26 Jul 2014 09:02:44 -0500, Lostgallifreyan
wrote:

Nope. It's one of those consumer widgets, one o millions, that have a
disclaimer saying that some limited interference must be accepted. Knowing
this, it isn't even worth trying to police the issue, and probably impossible
anyway. Computer based stuff just does this to us, there's no stuffing THAT
genie back in the bottle now.

Much depends on the device causing the problem. It's often cheaper
and easier to just buy the owner a new device instead of trying to fix
it. I've done that a few times with Chinese junk that never had a
prayer of meeting FCC Part 15 incidental radiation limits. So far,
I've replaced one ethernet switch, one 4 line phone, and 2 security
cameras in the neighborhood. Also, a mess of junk switcher type cell
phone chargers.

However, you can't do that if you don't know what's causing the noise.
So, take your portable radio, wrap it in aluminum foil to REDUCE the
sensitivity, and snoop around the building until you find the culprit.
The rest you can figure out yourself. Hint: Diplomacy works.


--
Jeff Liebermann
150 Felker St #D http://www.LearnByDestroying.com
Santa Cruz CA 95060 http://802.11junk.com
Skype: JeffLiebermann AE6KS 831-336-2558

Jeff Liebermann wrote in
:

Much depends on the device causing the problem. It's often cheaper
and easier to just buy the owner a new device instead of trying to fix
it. I've done that a few times with Chinese junk that never had a
prayer of meeting FCC Part 15 incidental radiation limits.

That could work. I agree, the price of the widget and a bit of diplomacy
might go further than any other effort. If it becomes a problem I'll try
that.

Jeff Liebermann wrote in
:

Also, a mess of junk switcher type cell
phone chargers.


Nice catch. The noise has a pulsed interval very similar to the type of Li-
ion charger that pauses to measure voltage every second or so. It might be
one. Thing is, it is the interval that noises, not the main duration, so I
think it might be a net boz sending regular packets when idle.

In article ,
Jeff Liebermann wrote:

Much depends on the device causing the problem. It's often cheaper
and easier to just buy the owner a new device instead of trying to fix
it. I've done that a few times with Chinese junk that never had a
prayer of meeting FCC Part 15 incidental radiation limits. So far,
I've replaced one ethernet switch, one 4 line phone, and 2 security
cameras in the neighborhood. Also, a mess of junk switcher type cell
phone chargers.

*rolls eyes*

A few years ago I helped chase down a noise source which was wandering
randomly through the 2-meter repeater input sub-band, and causing
prolonged noisy squelch tails on the ends of transmissions on several
different repeaters in the Silicon Valley area. It turned out to be a
(famous name) 5-port Ethernet hub, which was leaking its internal
clock-oscillator signal into all ports and back into its power supply
and was "turning the entire home wiring into a giant antenna" (as the
house-wiring-TV-antenna gimmicks used to say, decades ago).
Horrid... I could practically hear my spectrum analyzer cringe.

The owner was extremely cooperative, immediately agreed when I offered
to replace the hub with one from my own collection of spares, and the
problem went away and hasn't recurred in the years since. An unusual
failure mode, I guess (fortunately!)

On Sat, 26 Jul 2014 21:24:11 -0700, (David
Platt) wrote:

It turned out to be a
(famous name) 5-port Ethernet hub, which was leaking its internal
clock-oscillator signal into all ports and back into its power supply
and was "turning the entire home wiring into a giant antenna" (as the
house-wiring-TV-antenna gimmicks used to say, decades ago).
Horrid... I could practically hear my spectrum analyzer cringe.

Yep. I also know how to shoot myself in the foot. When I replaced
the neighbors noisy ethernet switch, he gave me the old switch for
recycling. Instead, I threw it into my pile of network boxes for a
later autopsy. After about a year, the post-it note marking it as
defective was lost. I needed a switch for the local club station, so
I grabbed the noisy switch and left. The complaints started about a
week later. Oddly, the 2.4GHz link between the repeater building and
the club station was the first to suffer interference problems. I
think just about every radio on the hill had problems, including the
county radios. On the principle of "whatever I did last was probably
wrong", I retraced my steps and eventually found the noisy switch. I
recall that it was made by Edimax, but don't recall the exact model
number.

As for "turn your house wiring into a giant TV antenna", that was my
start in electronics. I recall the ads in the back of Popular
Electronics and was intrigued by the principle. I learned that inside
the magic coupling box was a "capacitator" and that if one had an
AC-DC powered TV, it could be rather dangerous if connected
improperly. What got my attention was that it was an obvious fraud,
yet also quite successful considering that the ads were everywhere and
appeared in every electronics magazine. Instead of the traditional
policeman or fireman, I decided to become an electronics crook when I
grew up. That was heady stuff for a 9 or 10 year old. My parents
grudgingly approved if I agreed to become and engineer first, and
later a crook. That seemed reasonable and I continued on path to
success. Unfortunately, I began to reconsider when I discovered that
the owner of the company (Charles Torelli) had been busted in New York
for fraud, and served some prison time.

--
Jeff Liebermann
150 Felker St #D http://www.LearnByDestroying.com
Santa Cruz CA 95060 http://802.11junk.com
Skype: JeffLiebermann AE6KS 831-336-2558

On Sun, 27 Jul 2014, Jeff Liebermann wrote:

On Sat, 26 Jul 2014 21:24:11 -0700, (David
Platt) wrote:

It turned out to be a
(famous name) 5-port Ethernet hub, which was leaking its internal
clock-oscillator signal into all ports and back into its power supply
and was "turning the entire home wiring into a giant antenna" (as the
house-wiring-TV-antenna gimmicks used to say, decades ago).
Horrid... I could practically hear my spectrum analyzer cringe.

Yep. I also know how to shoot myself in the foot. When I replaced
the neighbors noisy ethernet switch, he gave me the old switch for
recycling. Instead, I threw it into my pile of network boxes for a
later autopsy. After about a year, the post-it note marking it as
defective was lost. I needed a switch for the local club station, so
I grabbed the noisy switch and left. The complaints started about a
week later. Oddly, the 2.4GHz link between the repeater building and
the club station was the first to suffer interference problems. I
think just about every radio on the hill had problems, including the
county radios. On the principle of "whatever I did last was probably
wrong", I retraced my steps and eventually found the noisy switch. I
recall that it was made by Edimax, but don't recall the exact model
number.

Masking tape is a better choice, it stays on for much longer.


As for "turn your house wiring into a giant TV antenna", that was my
start in electronics. I recall the ads in the back of Popular
Electronics and was intrigued by the principle. I learned that inside
the magic coupling box was a "capacitator" and that if one had an
AC-DC powered TV, it could be rather dangerous if connected
improperly. What got my attention was that it was an obvious fraud,
yet also quite successful considering that the ads were everywhere and
appeared in every electronics magazine. Instead of the traditional
policeman or fireman, I decided to become an electronics crook when I
grew up. That was heady stuff for a 9 or 10 year old. My parents
grudgingly approved if I agreed to become and engineer first, and
later a crook. That seemed reasonable and I continued on path to
success. Unfortunately, I began to reconsider when I discovered that
the owner of the company (Charles Torelli) had been busted in New York
for fraud, and served some prison time.

My sister bought one of those phone line antenna things about five years
ago. It was new, and obviously junk. I felt so bad that she'd thought it
would help.


Michael