- This topic has 5 replies, 3 voices, and was last updated 18 years, 10 months ago by
.
-
Posts
-
This was rather odd. Went to a customer yesterday with a Bosch WFF1201 to fit a tub spring. It’s in a little utility off the kitchen. Anyway, left it doing a rinse and spin and went into the kitchen to write out the bill, heard the machine start to wind up into spin, and the radio turned to gibberish. This is one of these new fangled DAB digital things. Purely out of interest, I got my portable, non-DAB radio from the van, tuned to the same station and it was absolutely fine.
Machine had brushes about 9 months ago, so they’re bedded in nicely. I suppose the suppressor isn’t covering the right frequency?
Be interested in comments as to what’s happening.
Chris.
Re: Radio Interference
My DAB is more or less next to our Bosch Exxcel and not a sausage 😕
DAB Reception Problems
DAB is advertised as being interference-free and is supposed to be easier to receive than FM. Unfortunately the reality is that DAB’s reception is far from perfect. Interference in the form of multipath can reduce the signal strength at the main carrier frequency and this result in too many bits of the digital signal being in error and a sound that is commonly called “bubbling” or “boiling mud” – because of the similarity between these sounds and what you hear on your DAB radio. This is quite a common problem with reception of DAB signals. If the multipath interference gets any worse than when you hear the bubbling sounds then the signal will dropout altogether and the audio mutes. This too is not uncommon, and you won’t see this mentioned in the DAB advertisements.It is a common misconception that DAB can easily be received using a wire aerial that comes supplied with the DAB radio. In some cases this is true, but in many/most cases this is not the case and you may well have to purchase a “proper” (i.e. metal rod-type) aerial
Greg
PS – Martin may know more about this QRM 😀
Duff filter block or iffy earth, I’d think. Unfortunately, digital transmissions can be more affected by RFI as any disturbance loses a whole packet of info…
Re: Radio Interference
Is that the same thing that happens to broadband when transmitted down a phoneline dpm?
Greg
Would be, yes. It’s all down to the error correction although ADSL has other tricks up it’s sleeve as it can monitor line noise and alter the transmission rate for best results, minimising retrys.
/or are you talking about the way the data signal is superimposed over the voice then filtered off?
- You must be logged in to reply to this topic.