[Nottingham] The arguments with WiFi continue

[Martin]

Re:

> Finally, do you have any knowledge of your neighbours' electronics at
> all? Those power socket range extenders are a nightmare for RFI. If
> something of theirs is getting into their AC circuits you could be
> hosed until chokes are fitted etc.

I'll agree with that unfortunate note... WiFi uses an elaborate radio
transceiver. Some of those mains devices could mean complete
obliteration for anything nearby for radio if you have an unfortunate
combination of mains network device/adapter and mains wiring acting as
an unfortunately good aerial...

(The damnable things should be banned, along with the hopelessly
outdated old-telephone-wires equivalent called ADSL... :-( )



However, my first bet is still with the MIMO operation and then possible
channels clash with neighbours.

Note also that it only takes one device from your neighbour on 802.11b
to bring all your devices down to that speed for sharing that WiFi space...


Good luck!

Cheers,
Martin


On 16/05/16 10:06, Luke wrote:
> Inclined to agree with Martin. I wonder if you could list out any
> electronics within the immediate vicinity of the set up. You tried them
> off, I'm assuming none were in standby, so it's probably creeping in
> from elsewhere (if RFI is the issue). Still worth a triple-check.
> 
> Ferrites on the leads, swapping out HDMI cables as I mentioned
> previously (or temporarily disconnecting). It's not just the frequencies
> the bad electronics leak at, but the 2nd and 3rd harmonics that can get
> you. You could also try like Martin says temporarily shielding the area
> with foil, re-siting the gear and confirming it's RFI by swapping out
> parts. I know, I know, but still...
> 
> Finally, do you have any knowledge of your neighbours' electronics at
> all? Those power socket range extenders are a nightmare for RFI. If
> something of theirs is getting into their AC circuits you could be hosed
> until chokes are fitted etc. Try an AM radio on static and see if you
> can find any spikes on the neighbour sides. Also try cutting your power
> to rule yourself out :)
> 
> That's all I've got for now. Sounds like you've got an external gremlin
> if you've checked everything in-house so thoroughly. Keep us posted.
> 
> Luke
> 
> 
> On Mon, May 16, 2016 at 12:47:39AM +0100, Martin via Nottingham wrote:
>> On 15/05/16 20:33, Jason Irwin via Nottingham wrote:
>>> I knew Broadcom were the work of the devil, but I thought Intel was
>>> meant to be OK.
>>>
>>> I tried a USB antenna borrowed from a Pi (LB-Link thing that's reported
>>> as "Realtek Semiconductor Corp. RTL8188CUS 802.11n WLAN Adapter").
>>> It'll only connect to 2.4Ghz but is 11n and it reports ~19Mbits/sec just
>>> like the internal card and the phone for the 2.4Ghz network.
>>> The antenna is claimed to deliver 150Mbps:
>>> https://www.adafruit.com/products/1030#technical-details-anchor
>>>
>>> J.
>>
>> Are your devices "MIMO" enabled and with suitable multiple antennas?...
>>
>>
>> See:
>>
>> http://www.dd-wrt.com/wiki/index.php/Wireless-N_Configuration#20MHz_vs_40MHz
>>
>> ... and:
>>
>> http://nottingham.lug.org.uk/2013/01/what-wifi-channel/3840
>>
>>
>> And you may need some aluminium foil shielding/wallcoverings to keep the
>> neighbours out!
>>
>>
>> Good luck?
>>
>> Cheers,
>> Martin


-- 
- ╔═══════════════════╦══════════════════════════════════════════╗
- ║   Martin Lomas    ║ OpenPGP (GPG/PGP) Public Key: 0xCEE1D3B7 ║
- ║ martin@ ml1 co uk ║ Import from   hkp://subkeys.pgp.net   or ║
- ║ ----------------- ║ http:// ml1 .co .uk/martin_ml1_co_uk.gpg ║
- ╚═══════════════════╩══════════════════════════════════════════╝