I can hear my Wifi card on my TV!

As the subject really. It sounds like the interference from a mobile phone
but with longer pulses.

"fishman" <(E-Mail Removed)> wrote:
>It sounds like the interference from a mobile phone
>but with longer pulses.

Move the AP/client further from the TV/antenna, change the WiFi
channel, or get a TV that's not so susceptable...

"fishman" <(E-Mail Removed)> wrote in message
news:(E-Mail Removed)...
> As the subject really. It sounds like the interference from a mobile phone
> but with longer pulses.
>
I can hear my TV on my wifi, and see it too

might try plugging your ap into different 120v outlets, maybe if its not on
the same circuit the noise will go away.

On Fri, 21 Jan 2005 10:47:30 -0000, "fishman" <(E-Mail Removed)>
wrote:

>As the subject really.

Swell. I have to reconfigure my news reader to display the subject so
I can figure out what you're talking about. Instead of reminding me
to read the subject line in the body of the message, it's so much
easier to just repeat the subject (in greater detail) in the body of
the message.

>It sounds like the interference from a mobile phone
>but with longer pulses.

The TDMA/GSM/IDEN RF pulses from a cell phone are somewhat similar to
the beacon broadcasts from a wireless access point. They have a
different repetition rate, but they all generally sound the same.
Your TV is rectifying some of the RF. Since you didn't mention
anything about the TV picture, I'll assume that it's an audio only
phenomenon. It's probably the audio circuitry in the TV that's doing
the rectification. You could just move the access point away from the
TV and eliminate the problem. Or, you could find the point of entry
and apply some shielding or RF blocking ferrite beads. It could be
coming in via some of the audio amplifier phone cables, especially if
the TV has a high gain phono (turntable) input.


--
# Jeff Liebermann 150 Felker St #D Santa Cruz CA 95060
# 831.336.2558 voice http://www.LearnByDestroying.com
# (E-Mail Removed)
# (E-Mail Removed) AE6KS

"Jeff Liebermann" <(E-Mail Removed)> wrote

> Swell. I have to reconfigure my news reader to display the subject so
> I can figure out what you're talking about. Instead of reminding me
> to read the subject line in the body of the message, it's so much
> easier to just repeat the subject (in greater detail) in the body of
> the message.

Thanks for going to the effort of that so you can reply! I think your
newsreader software is a bit ropey, if you can't find out what the subject
of a message is.

-snip informative reply-

Thanks, I understand now. I can't seem to recreate the problem again, so
perhaps it was to do with the atmospherics on the day I first experienced
it.

> # Jeff Liebermann 150 Felker St #D Santa Cruz CA 95060
> # 831.336.2558

I don't know of many people who put their direct contact details on usenet.

On Mon, 24 Jan 2005 15:50:07 -0000, "fishman" <(E-Mail Removed)>
wrote:

>"Jeff Liebermann" <(E-Mail Removed)> wrote
>
>> Swell. I have to reconfigure my news reader to display the subject so
>> I can figure out what you're talking about. Instead of reminding me
>> to read the subject line in the body of the message, it's so much
>> easier to just repeat the subject (in greater detail) in the body of
>> the message.

>Thanks for going to the effort of that so you can reply! I think your
>newsreader software is a bit ropey, if you can't find out what the subject
>of a message is.

It's not a major challenge, just an inconvenience. I have Forte Agent
2.0 set to not display the header when displaying the message. This
gives me more room to work, primarily so I can more effectively
plagerize web pages and usenet postings. To display the header, I
just right click, and select "Show Header Fields". When done, I have
to do it again as it's a toggle.

In the distant past (1987?), when I was shoveling usenet news via
Bnews at 2400 baud, paid for connect time by the minute, and there
were perhaps 100 newsgroups, economy of content was important.
Signatures were limited to 4 lines. The amount of quoted text was
severely restricted. Salutations were discouraged. Subject lines
were not repeated in the body. The idea was to reduce the number of
bytes in each message. Today, we have flat rate service,
multi-megabloat bandwidth, and headers often larger than the message
body. I guess this is called progress. Some of the habits of
economoy that made good sense in the 1980's no longer make much sense.
Non-repetition of the Subject line is one of those.

Basically, if you expect someone to spend the time to answer your
questions, make an effort to provide them with sufficient data to make
a suitable guess, and make it easy for them to read. Obstacles are
irritating.

>-snip informative reply-

Was it "heard" on all channels or just some channels? Audio only?
Through a VCR, Tivo, or DVD player?

>Thanks, I understand now. I can't seem to recreate the problem again, so
>perhaps it was to do with the atmospherics on the day I first experienced
>it.

Atmospherics or location sensitive interference are a possibility.
However, I predict that it will be back, usually in the middle of an
important show. If it fixed itself, and it was audio only, my guess
is a loose connector, where the center pins made a connection, but the
shield was lacking.

>> # Jeff Liebermann 150 Felker St #D Santa Cruz CA 95060
>> # 831.336.2558

>I don't know of many people who put their direct contact details on usenet.

I've been doing that for quite a while. The address is my palatial
office. The only problem is that someone occassionally calls to get a
question answered. Usually, they're desperate (work related). I try,
but it usually burns too much time. Sometimes, they send money (or
paypal). The telemarketer will call anyway as I'm also listed in the
phone book.

I consider it good form to know with whom I'm talking. Try wearing a
mask in public and see how people react. Tell them you're acting
anonymously due to fear of identity theft. I consider myself
responsible for everything I say and post. I also don't consider
hiding behind a mangled email address and signature to be a great
example of spam fighting.

Anyway, I hope this has explained a few things. I would move the
access point away from the TV.


--
Jeff Liebermann (E-Mail Removed)
150 Felker St #D http://www.LearnByDestroying.com
Santa Cruz CA 95060 AE6KS 831-336-2558

Today, we have flat rate service,
> multi-megabloat bandwidth, and headers often larger than the message
> body. I guess this is called progress. Some of the habits of
> economoy that made good sense in the 1980's no longer make much sense.
> Non-repetition of the Subject line is one of those.

I'm always amused by the fellow going off on someone for a large signature
line, when in the next newsgroup over, someone's uploading the latest and
greatest pornfest movie at 700+ meg..


> Was it "heard" on all channels or just some channels? Audio only?
> Through a VCR, Tivo, or DVD player?

I saw some suggestions that it was coming in through the power earlier,
which is extremely unlikely. FAR more likely is a phenomenon called "direct
rectification".

Chips, transistors, and diodes all can do this to some degree, and the
pulses of RF from a Wi-Fi box are well suited to being detected by this
method. The RF hits these semiconductors, and a voltage is developed. This
is more or less how the old crystal radios worked. Moving the Wi-Fi unit
further away will help a lot, as this is governed by the inverse square law.
In short, if you double the distance, you get 1/4 the interference.

Both units are operating under part 15 though, so the interference is just
something you'll have to live with if you can't solve it.

The funny thing is that my ham licence allows me to run 1500W of video if I
choose to, on frequencies that overlap the Wi-Fi band. It wasn't my
decision to co-locate these allocations, but part 15 devices "must accept
any and all interference, including that which may cause undesired
operation."

On Mon, 24 Jan 2005 13:29:16 -0500, "Dave VanHorn"
<(E-Mail Removed)> wrote:

This is gonna sound like hair splitting but....

>I saw some suggestions that it was coming in through the power earlier,
>which is extremely unlikely. FAR more likely is a phenomenon called "direct
>rectification".

Actually, entry via the power line is quite possible. Long ago, I did
some type acceptance and type certification tests on a contraption
that had a noisy switching power supply. We installed an unshielded
pair of RF chokes at the power line, a disk ceramic across the line,
and an MOV (because it was a convenient place to put it). That
eliminated the conducted and radiated junk from the power supply.

However, we then started getting reports of radio station (FM and TV)
pickup that were not present before the chokes were added. It seems
that the chokes were great at 100KHz, where the power supply operated,
but not so good above 100MHz. Instead of blocking the RF coming in
via the power line, they would re-radiate it to the nearby sensitive
circuitry. Rather than apply yet another band-aid, I elected to find
the point of the RF sensitive circuit that was causing the problem. A
few ferrite beads and bypasses eliminated the problem.

Todays TV's and Hi-Fi's are RF similar. The circuitry has little RF
bypassing and can pickup and rectify at almost any frequency.
Xsistors and IC's have much more gain at high frequencies than older
devices. The only saving grace is that the leads are MUCH shorter
than older discrete component designs, and therefore pickup less junk.
(Wires radiate and pickup, components do not.) However, at 2.4Ghz,
the traces and wires are electrically large and act as wonderful
antennas.

I would say that there's a small chance that the 2.4GHz arrived via
the power line and was rectified by something, causing the noise.
However, it's much more likely that it entered via an loose phono or
coax connector.

>Chips, transistors, and diodes all can do this to some degree, and the
>pulses of RF from a Wi-Fi box are well suited to being detected by this
>method. The RF hits these semiconductors, and a voltage is developed. This
>is more or less how the old crystal radios worked. Moving the Wi-Fi unit
>further away will help a lot, as this is governed by the inverse square law.
>In short, if you double the distance, you get 1/4 the interference.

I'll add some more hair splitting. Semiconductor devices rectify RF
based on the square law diode curve. Therefore, the rectified voltage
would decrease with the square of the applied RF, which decreases with
the square of the distance. Move twice as far away and you only get
1/16th the detected DC.

>Both units are operating under part 15 though, so the interference is just
>something you'll have to live with if you can't solve it.
>
>The funny thing is that my ham licence allows me to run 1500W of video if I
>choose to, on frequencies that overlap the Wi-Fi band. It wasn't my
>decision to co-locate these allocations, but part 15 devices "must accept
>any and all interference, including that which may cause undesired
>operation."

More power to you. This paradox is one that the FCC will need to deal
with eventually. In addition, ham radio operation on 2.4Ghz is a
licensed service. Therefore, ham radio has priority over unlicensed
wireless. There's also substantial confusion as to what happens when
hams are running 802.11 modulation using the ham frequencies. 802.11
is an IEEE specification and not approved or controlled by the FCC.
Nice mess. Anyway, I can predict the outcome between a few thousand
hams using 2.4Ghz and a few million Part 15.247 devices backed by some
major corporations. The hams will lose.

Enough hair splitting as I have little hair left to split.


--
Jeff Liebermann (E-Mail Removed)
150 Felker St #D http://www.LearnByDestroying.com
Santa Cruz CA 95060 AE6KS 831-336-2558

On Mon, 24 Jan 2005 15:50:07 -0000, in alt.internet.wireless , "fishman"
<(E-Mail Removed)> wrote:

>Thanks for going to the effort of that so you can reply! I think your
>newsreader software is a bit ropey, if you can't find out what the subject
>of a message is.

Agent displays the subject just fine, but it doesn't waste real estate
doing it, and ask yourself, should someone really have to read teh subject
line to understand what your posting means?


--
Mark McIntyre
CLC FAQ <http://www.eskimo.com/~scs/C-faq/top.html>
CLC readme: <http://www.ungerhu.com/jxh/clc.welcome.txt>

What's it saying?, and what channel do you get it on?