[MacNNUK]

My iMac interferes with my UK Legal 2.4ghz CCTV wireless system, it radiates enough RF to cause some disturbance.

The iMac and CCTV receivers are in the same room, transmitters a room or two away.

Airport is turned off.

Airport does appear, at least on paper, to use similar frequencies, perhaps some radiation even when turned off ?

Bluetooth is off.


The CCTV still works, but I get constant flashing lines on the CCTV system, whilst my iMac is on, even in sleep mode.

Just tried it, the interference is still there in sleep mode, but less so.

When I wake the iMac, the interference goes crazy for a few secs, then settles down.

A bit like unsuppressed car / motorbike ignition.

Worse affected is CCTV Channel 4.

Similarly, my microwave has a much more pronounced effect on the CCTV. Although only intermittently.

Anyone else notice this ? Explanatiion ?

I presume the 2.4ghz CCTV band is not in common use in the USA, otherwise the FCC would prohibit this spurious radiation.

CCTV 2.4ghz band is 2,400-2,483 mhz.

CCTV FREQUENCY:
CH1: 2414MHz
CH2: 2432MHz
CH3: 2450MHz
CH4: 2468MHz


This may also explain why, to some extent:

http://www.cisco.com/en/US/docs/wire...e/Channel.html

But why does it interfere when turned off ?

Is there some other hardware within the iMac radiating 2.4ghz ish ?

( When I turn Airport on, the interference does get slightly worse, and affects other channels more. )

So presumably, my microwave also interferes, albeit temporarily with my Airport to router, though I am downstairs using microwave, and therefore unable to use iMac at same time, which is upstairs.

As it is, I do not have Airport turned on, I prefer my router connection to be cabled.

This is also useful:
http://802problems.com/html/interference.html

" 802.11 b/g is a public protocol and is widely used. The 2.4 GHz frequency is used for Microwave ovens, Wi-Fi, Television Control, Microsoft X-Box, CCTV cameras, Bluetooth for Mobile phones and many more."

My mobile phone has bluetooth enabled, but is off, (It's 4am here).

I'll turn bluetooth on mobile phone off daytime, and see if it has any effect .

[MacNNUK]

Found the problem...

Just realised I have a wireless mouse.

It's the Apple Mighty Mouse.

Noticed it when I squeezed it as iMac started up, and it disturbed CCTV !

More investigation required, my end......

Problem traced.. battery taken out of mouse, interference stops immediately !

Pity it interferes with the CCTV though.

Don't think it's a 10.5.4 thing, as with iMac off, when I click mouse, it causes some interference, not quite as bad, but it's there ok.

So, back onto wired mouse for a while.