DAB reception suddenly poor

I took my Jimny for a drive and monitored the DAB service using the screen.

I had fewer drop outs, but they were still there on the independent station, although I noticed the following

- the signal strength didn’t drop very low, but the radio dropped out.
- when the radio lost reception the FIC and MSC values (data channels) both went really high and -1 when the service was lost, even though signal strength was fine.
- the R/S-FEC (forward error correction) was zero for the independent station.

The independent station is running DAB+, BBC is just running DAB and has a value of R/S-FEC of 30, meaning it is running forward error correction.

It looks like the Bosch SLDA doesn’t implement FEC in DAB+ and therefore doesn’t perform as well as it should.

What I know about DAB would go on a postage stamp, but DAB+ is just a shift to AAC encoding to reduce the bit rate so more channels will fit in the same bandwidth, I doubt if they would increase it back up with much error correction, so it could well be the station.

 

What I read said that it was recommended to implement forward error correction on DAB+ to increase resilience and reduce drop outs, although you might be right, the likes of the BBC probably have less channels so can afford the FEC overhead and the independents can’t.

I drove down my test road in my other car today, the DAB on the same station had a few brief drop outs in the same place as my Jimny (I always thought my Jimny was better).

However, where my other car drops it for a second or less the Jimny goes off for 20-30 seconds until it re-syncs, so perhaps the Jimny is just slow to decode the signal after an interruption?

Robin

Now you mention it, when I start mine up on the drive, the (DAB) radio starts blaring for a second or so, then it drops out, and takes what seems like ages to regain the signal, probably around 10 seconds, it is usually playing by the time I've dropped the dessicant bags into the disklok and put my seatbelt on all ready to go.


(Tip: don't start the engine with the disklok still on, as the steering powers up and the weight of the arm on the disklok will turn it round until it jams )