[David (2)]

Last week, sat in the car park during lunch break I had the car radio set to WAVE 105 (105.2fm), and for about 30secs the audio faded (common as its a long way from the IOW transmitter site!), and was replaced by a French speaking presenter. I didnt post last week, but it happened again today.

Any idea what French station this is, and how on Earth does it manage to reach Chippenham in Wiltshire?

[fmradiotuner1]

That would be the Massive France Info I have managed to pick this up most places I go to around the coast here apart from in the West.
I even got them in Selsey and as far as Hunstanton.

[Willum]

Yes, that was almost certainly France Info, the national rolling news and information station.

http://www.franceinfo.fr/

The 105.2 relay people can usually hear is in the Lille area, powered at 500kW. Needless to say, it's audible over a very large area by FM standards.

[brumlad36]

Originally Posted by David (2)

Last week, sat in the car park during lunch break I had the car radio set to WAVE 105 (105.2fm), and for about 30secs the audio faded (common as its a long way from the IOW transmitter site!), and was replaced by a French speaking presenter. I didnt post last week, but it happened again today.

Any idea what French station this is, and how on Earth does it manage to reach Chippenham in Wiltshire?

Yes, it's France Info from Lille on 105.2Mhz. Other high power frequencies to try from the same transmitter are 88.7Mhz, 94.7Mhz, 98.0Mhz and 103.7Mhz.

The following web site has not been updated recently. Digital switchover (TV) has happened and isn't shown.
France Info is actually transmitted at 200kW with a notch in our direction. I receive 94.7Mhz (France Bleu) and 98.0Mhz (France Culture) both at 125kW, much stronger than France Info 105.2Mhz. They all work best with horizontal polarisation.

http://www.tvradio-nord.com/emetteur.../bouvigny.html

Chris.

[brumlad36]

I just noticed that, although the website http://www.tvradio-nord.com/emetteur.../bouvigny.html hasn't been updated recently, the new digital frequencies are shown under -> "TV numérique TNT (jusqu'au 1 février 2011)"

I think the TV signals are notched in our direction, as I've never received French TV, here in Lincoln, even during a very strong "lift".

Chris.

[Willum]

Does 'notched' mean 'nulled' or, as I understand the latter to mean, restricted?

I always though that Wrotham and the Dover relays of the nationals were nulled to the south, hence the poor coverage in Calais. You can see the mast with the Dover relay of Classic FM on it from Calais quayside, but the reception is still not very good.

[martinwatkins]

Wrotham is - pretty much - omnidirectional. Pretty much because there are ripples in the pattern, but it was designed to be omnidirectional. Reception in Calais is not too good because the latter is at ground level, but in fact Wrotham comes in fairly well once you get south of Calais and onto higher ground.

Dover (Swingate) BBC is somewhat directional (tx panels on 13 degrees and 243 degrees) and although it gets to Calais it peters out soon afterwards with Wrotham being stronger. I'd have to look up Dover Classic FM (Church Hougham) but I imagine you're right.

Lille FM is not actually notched in our direction, although there is a slight (deliberate) shift in the polar diagram to the south/south west. You can look at it here:

http://www.annuradio.fr/details.php?...adios&code=710

The ripples that are shown on the diagram are very similar to what happens at Wrotham, and are typical of this sort of aerial, although Lille is a four sided system whereas Wrotham is a three sided aperture. Wrotham's original slot cylinder aerial (we're going back to pre 1981 here) was somewhat smoother.

105.2 Lille is often quoted as 400 kW erp, (someone above has even bumped it up to 500 kW which I think is a little fantastical, I've never seen any serious reference to half a megawatt in the French publications!) and that (400 kW) may be what was applied for in international agreements, but that link (and he's a stickler for accuracy so I suspect he's checked) shows it running 200 kW. The other FMs from there are shown as 100 kW - they used to run at 150 kW. When French FM sites are rebuilt (as many have been between 1985 and today) there's often a review of the power, some have increased (Brest Roc Tredudon is an example) but many have been tamed a bit. Similarly for French analogue TV where many (most in fact) of the high power sites were roughly halved in power, many of the nominally 1000 kW sites were reduced to 400 - 600 kW in the early 1990s. So it's not surprising that the same thing appears to have happened at Lille Bouvigny.

[brumlad36]

Originally Posted by Willum

Does 'notched' mean 'nulled' or, as I understand the latter to mean, restricted?

I always though that Wrotham and the Dover relays of the nationals were nulled to the south, hence the poor coverage in Calais. You can see the mast with the Dover relay of Classic FM on it from Calais quayside, but the reception is still not very good.

Sorry, I was probably not using the correct term. I did mean nulled or restricted.

See martinwatkins reply (above) for a more full technical explanation.

Chris.

[martinwatkins]

They're often interchanged. I suppose I think of a notch as a very sharp reduction covering no more than a 30 deg arc, nulled as a bit wider, and restricted as much less sharp. But I wouldn't say that was necessarily how a true beam shaping engineer would describe them!!

I suspect true notches are easier to achieve at UHF than VHF.....

[ACL777]

Was this received via sporadic e considering the station in question came and then abruptly disappeared . If it was ever present during flat conditions surley you would hear it regularly and at a more constant audible level ?

[brumlad36]

Originally Posted by ACL777

Was this received via sporadic e considering the station in question came and then abruptly disappeared . If it was ever present during flat conditions surley you would hear it regularly and at a more constant audible level ?

It wouldn't be Sporadic E. They would have to be receiving from the very south of France (or Corsica), as the "hop" from northern France would be received in Scotland or further away. Sporadic E usually occurs at distances of between 500 miles and 1500 miles. The E layer of the ionosphere is about 75 miles up.

Chris.

[hanssolo]

Originally Posted by brumlad36

It wouldn't be Sporadic E.

More like "Tropospheric ducting"?
http://en.wikipedia.org/wiki/Tropospheric_propagation

[Pemblechook]

Sounds like meteor scatter. Signals can last from 1 - 30 seconds and can be quite strong.

[Nick_G]

Originally Posted by Pemblechook

Sounds like meteor scatter. Signals can last from 1 - 30 seconds and can be quite strong.

Sounds more like aircraft scatter to me. The distance from Lille to Chippenham would be approx 350 km which is very short for meteor scatter. Aircraft scatter can peak up quite well - Lille peaks up in stereo on my set-up via this mode.

If it was a very sensitive car radio with a decent aerial in a spot with good take-off in the direction of Lille it might even have been troposcatter, where a small part of the signal is scattered back by random fluctuations in the atmosphere. Signals via this mode are very weak though and you need a good set-up to make the most of it.

I get Lille all the time here and the signal is very unstable and fluttery. So with a good set-up you can get distant signals fluttering up and down across the band on empty channels. During a tropo the signals become stronger and much more stable in strength.

[Pemblechook]

Too short for MS. Used to get a lot of aircraft flutter when we used AM on 144. Never hear it now FM and SSB are used.

[Nick_G]

Here's a clip of France Inter on 103.7 from the same site as 105.2 (Lille-Bouvigny), recorded about 10 minutes ago. This is typical reception:

http://www.box.com/s/984ef20a348079d09188

You can hear how unstable the signal is. The weather at present is dominated by low pressure so conditions are flat.

I'd imagine you heard something similar - France Info just happened to peak up when Wave 105 had faded out.

[Pemblechook]

There is SP E on 50 MHz. N W France to Madeira. Kent to Spain and Greece.

[Mark C]

Originally Posted by Pemblechook

Sounds like meteor scatter. Signals can last from 1 - 30 seconds and can be quite strong.

About 30 years ago I suddenly received Radio London, Capital and LBC in Plymouth, noise free stereo, lasted no longer than a couple of minutes. It was a winter's evening. I don't know what else might have been there, there was suddenly a lot of birdies affecting Plymouth Sound (96.0 in those days) which was Capital bursting through on 95.8, I checked 94.9 and 97.3, which were both just as powerful, then all three fizzled away.

[Pemblechook]

Too short a distance for MS really. The ionosphere would have to be very highly ionised to reflect at steep angles (short skip).

[smorris]

Originally Posted by martinwatkins

Lille FM is not actually notched in our direction, although there is a slight (deliberate) shift in the polar diagram to the south/south west. You can look at it here:

Although according to that diagram it's reduced by 10dB in some directions, which isn't really that slight... (200kW --> 20kW).

[Hybrid tellies]

Over the years I have heard a few strange micro tropo openings on FM. Sometimes lasting for less than a minute to over 10 mins. The most recent was on 105.20Mhz whilst listening to the weak Wave 105 signal from Chilerton Down it was completly taken over by a station playing modern Dance music. It lasted for less than a minute and the conditions were flat due to the unsettled weather. I suspect it was Kerrang from Sutton Coldfield. This burst of signal was to long for aircraft reflection. A few years ago whilst staying at a holiday park just outside Mevagissey in Cornwall, during a heavy hailstorm, I was listening to a very strong steady signal from Radio Bristol via Mendip on 95.50Mhz, they were talking about Concords final flight into Filton Bristol. The signal lasted for over an hour with little or no fading. Despite the disturbed weather conditions it had to be some kind of tropo enhancement as has already been mentioned the minimum skip distance for Sporadic E is aprox 500 miles.

[hanssolo]

Originally Posted by Nick_G

You can hear how unstable the signal is. The weather at present is dominated by low pressure so conditions are flat.

With the golf stream starting to pick up this time of year creating different layers of temperature and pressure over the channel, still think it could be some type of tropospheric ducting extending the range of the transmitter just a bit further than normal.

[martinwatkins]

Originally Posted by smorris

Although according to that diagram it's reduced by 10dB in some directions, which isn't really that slight... (200kW --> 20kW).

True, although you'd be "unlucky" to be right in the path of the deepest troughs (although someone has to be!).

I used to listen to Lille regularly on 88.7 MHz in London (aerial at the top of a nine storey building) and at my parents' home near Guildford. All gone now with Crystal Palace on 88.8 MHz, and France Musique isn't what it was back then....

Back then it was rare to have no signal at all, and most of the time a (noisy) stereo signal could be obtained. That was from the original mast at Bouvigny with 150 kW.

[brumlad36]

Originally Posted by martinwatkins

True, although you'd be "unlucky" to be right in the path of the deepest troughs (although someone has to be!).

I used to listen to Lille regularly on 88.7 MHz in London (aerial at the top of a nine storey building) and at my parents' home near Guildford. All gone now with Crystal Palace on 88.8 MHz, and France Musique isn't what it was back then....

Back then it was rare to have no signal at all, and most of the time a (noisy) stereo signal could be obtained. That was from the original mast at Bouvigny with 150 kW.

I have a similar problem with 88.7Mhz, as Belmont BBC R2 (88.8Mhz) knocks out Lille, here in Lincoln. To my surprise, during last month's "lift", I was able to hear France Musique on 88.7Mhz, using my Blaupunckt Casablanca CD52, connected to a 3 element external, horizontal aerial, directed at Lille (conveniently 90 degrees away from Belmont).

Even during "flat" conditions, it's unusual not to be able to hear something from Lille (CULTURE) on 98.0Mhz, using the above set up.

Chris.

[martinwatkins]

I've often wondered if that's why R2's frequency at Belmont is offset from what it should be (under the normal BBC planning system), ie 88.7 MHz.

Of course it allowed BBC Sheffield to use 88.6 MHz ab initio, but I don't think that was the reason for Belmont's offset.

I never got Lille 88.7 MHz when we lived not far from Spilsby for a while, so you're one up on me! Possibly because my 6 element was pointing inland...