FM frequencies in Dublin

[Mike]

What is this "new thechnology" the IRTC has discovered that allows more radio stations in Dublin ?

Presume they dont mean DAB

Or is it that said frequencies have been available for years but poor bandplanning ment they couldnt be used ?

[Peadar]

DAB is used in the UK but i think it's on Band-III (ie not the standard FM band).

[Mike]

Yeah DAB in the UK uses 217-230MHz but in Ireland frequencies below 223 are used for TV

[Justin Speck]

Planning is done on the basis of ITU recommendations. It is possible that BCI might now consider that real receivers have advanced from the standard being used for planning purposes - you know, real receivers could have better selectivity than the ITU "standard" one for instance.

Considering the performance of real radios rather than hypothetical ones could allow you to fit more stations in.

Just my 2d worth.

J

[Mike]

Given the way that RF performance of most low to mid end consumer recievers (with the possible exception of car radios) has DECLINED in the last 15-20 years thanks to penny pinching by manafacturers Id seriously doubt it.

A survey done about ten years ago indicated that 75% of commercially available recievers fail to meet CCIR spec's and theres no reason to believe that things have got any better since.

On the other hand the replacement of AFC with PLL digital tuning could possible enable closer spacing on account of less reciever drift ?

[Justin Speck]

Sadly I have to agree with you; while top of the range stuff has undoubtedly improved in performance, there is an awful lot of tat out there waiting to be bought by unsuspecting punters.

J

[Mike]

I remember about 15 years ago (when things were a lot better than they are now) some guy from BBC engineering complaining about reciever quality as well.

This was also a big consideration in the LPFM debate in the US (Commercial stations complained that if LPFM stations were allowed to operate 0.4MHZ away from them there would be interference on cheap radios)

Ive often thought it would be a good idea for some independent body (BBC ? NAB ? FCC ?) to operate some kind of certification and "quality mark" scheme with categories covering everything from cheap mono portables to hifi systems

[Mosfet]

Have to agree with everything Mike says,from what I can conclude not only receiver quailty is poor but also transmission gear has more harmonics that ever,sad to see this happen but it all comes down to money instead of preventing "R.F pollutions" :confused: