Interference from digital set top box


Hi All,
As some of you may know I had a high noise level which appeared intermittant
at first then solid.
Of recent times it has been a solid S9 on 80mx and S8 on 40mx day and
night.I guess the intermittant
part was the 11kv power lines out the front so one would think that will
continue from time to time.
In the finish, I tracked the solid interference down to a standard
definition set top digital TV box which was
in idle mode 24/7. Even when I disconnected the TV aerial leads (in/out) it
didn't change. I tried winding
the power lead on a ferrite bar and eventually the TV coax but no effect.
The plug pack is not a switching supply
either. It just plain seems the plastic cased unit radiates broadband
interference and doesn't need an aerial either.
The brand is a "KROSS" Model "DSK530STB" and I would be interested if the
same problem is noted with other
brands or models.
My noise level has dropped to S4-5 80mx (daytime) and S2-3 40mx. Big
difference to my ears.
Would be a shame if one of my neighbours bought one!!!!
73 de Peter
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Mid North Coast Amateur Radio Group Inc.
Coffs Harbour And District Amateur Radio Club Inc.
CW Operator's QRP Club Inc. No. #563
Wireless Institute Of Australia.
International Fox Tango Club.
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Reply to
Mac
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Does it have a C Tick? Maybe it would not have it through the approval if it was actually tested.
Reply to
sb
It costs too much to have C tick compliance, that would eat into the profits on their 10 containers of the spugie emitting ebay rubbish. Build a faraday cage for it.
Rob
Reply to
<R1rob>
Ah, it's the law.....
it also reduces the lawsuits if it has a potential fire danger...
Reply to
sb
Hello chaps,
This Kross STB was purchased from Woolworth Supermarket, Park Avenue Coffs Harbour an is supposed to be complient with Australian regulations.
Cya Mac
Reply to
Mac
And the key word is "supposed", until some one complains very loudly indeed, the authorities do not check that actual shipments comply with any regulations. Until companies are comprehensively fined, it is usually cheaper for them to ignore such regulations.
MrT.
Reply to
Mr.T
That would explain the same C tick registration numbers on different products....
Reply to
sb
It depends on who holds the registration - many devices are identical but simply "badge-engineered" for different suppliers.
The required response is clear:
1. contact the supplier and make noises about interference, suspected non-compliance etc,
2. contact the ACMA area office, lodge a formal complaint (make noises about suspect non-compliance or suspect labelling) - either pay your $60 or get your neighbours to also complain.
Keith G Malcolm VK1ZKM 3 September 2007
Reply to
who knows
A C-tick number (correctly known as Supplier Code Number) relates to the Australian supplier (i.e. importer or distributor), not the product.
This means you see:
1. the same product from different suppliers but with different supplier code numbers,
OR
2. different products all from the same supplier with the same supplier code.
sb wrote:
Reply to
DaSuthNa
Hey Mac, are you sure the plug pack is not a switchmode PSU? The broadband radiation you describe would seem to be more likely to eminate from a faulty switchmode. I had a Kross STB, but I gave it to my Mum when the Thompson unit she had suffered a failed PSU, which radiated in a similar way that you described. She couldn't pick up any AM radio due to the interference. Unplugging the Thompson fixed it.
I recall that the PSU on the Kross was very lightweight, so I assumed it to be a switchmode. I didn't crack it open to find out though :)
I eventually hooked up a conventional 12v DC regulated transformer wall wart to the Thompson, and it now works, although it does need to be unplugged every now and then when it locks up.
The Kross is still going OK. I recall that it used to squeel and break up when a certain light switch was turned on or off. I reduced the affect by winding the power lead onto a ferrite core.
WR
Reply to
Wayne Reid
Oh Bugger!!! it was a switch mode plug pack supply and thats where all the hash came from. Used a linear supply and all clear.
Cya Peter
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Reply to
Mac
I got caught out too with a switch mode from Jaycar, noise o plenty!
Reply to
Roj Blake
Thought so.
Reply to
Wayne Reid

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