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Kriesler 11-99 is making strange noises! is this normal?
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Return to top of page · Post #: 16 · Written at 9:45:47 PM on 1 June 2013.
	Melaine Location: Mount Barker, WA Member since 31 May 2013 Member #: 1351 Postcount: 9
Hi Maven.. that's really interesting! thanks for your reply, that sounds like it could be the explanation

Return to top of page · Post #: 17 · Written at 10:53:15 PM on 12 June 2013.
	Melaine Location: Mount Barker, WA Member since 31 May 2013 Member #: 1351 Postcount: 9
I did'nt have another radio to test the area with but shifted the Kriesler to the other side of the room and it doesn't make the noises anymore, so I guess it WAS picking up a signal 'unplugged' thanks to everyone who replied to my post

Return to top of page · Post #: 18 · Written at 9:04:12 AM on 13 June 2013.
	Marcc Location: Wangaratta, VIC Member since 21 February 2009 Member #: 438 Postcount: 5389
An incident in Wangaratta last week saw Telstra finally track a massive interference issue down to a light in a fridge. (ABC radio). Compact flourescent lights would have to be one of the dirtiest, RFI generating, forms of mass lighting ever created. One of the things these things will do is form a relaxation oscillator. Because we run electrical cables parallel to others, they capacitively induct into the adjacent cable. I have measured on one cable with a " flickering flouro" 145V with a DVM 43V with the AVO7x. I found with the two offending tubes (Variac) that they would "strike" at 30V. So depending on how much induction there is (and the switch does not need to be on) the line voltage will rise to a point where the tube strikes, discharges the charge and the whole cycle then starts all over again. Filament globes will not do this, as they present a constant resistive load on the circuit. Marc

Return to top of page · Post #: 19 · Written at 1:09:28 PM on 13 June 2013.
	GTC Location: Sydney, NSW Member since 28 January 2011 Member #: 823 Postcount: 6761
Compact flourescent lights would have to be one of the dirtiest, RFI generating, forms of mass lighting ever created. Yep, and some brands are worse than others. There's table lamp across the room from my little collection of valve radios and it's only when I changed the compact fluoro in it for a cheapie that came in a six-pack that I started to get noticeable RFI in all of the sets. Pulled out the CF and the RFI was gone. QED.

Return to top of page · Post #: 20 · Written at 1:29:32 PM on 13 June 2013.
	STC830 Location: NSW Member since 10 June 2010 Member #: 681 Postcount: 1302
LED lights powered with switched mode power supplies are very noisy too.

Return to top of page · Post #: 21 · Written at 3:03:26 PM on 13 June 2013.
	Maven Location: Canberra, ACT Member since 23 August 2012 Member #: 1208 Postcount: 584
It seems that standards invigilators no longer consider that interference to AM radio signals is worth clamping down on. The thing is, the audible interference from an AM radio can be the signal to warn you that other things, such as IT devices, may be subject to interference that is harmful without being audible. Maven

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