Bleeps on VHF in France

[ShotOne]

Flying in French airspace I hear occasional loud bleeps of around one second duration over the VHF RT, irregular but just frequent enough to be quite annoying. Anyone know what they are?

[esreverlluf]

A few things that spring to mind are that it could be ACARS selected to the wrong frequency, illegal paging equipment or some sort of tone encoder activity.

Suggest you enquire next time you hear it and see if the ATCO knows or can find out.:}

[alf5071h]

The French Air force had a very innovative interaction between the landing gear down indication and VHF transmission. The response to a check call of ‘Gear Down’ was to press a button on the gear indicator, this transmitted short ‘beep -beep’ providing that the gear was down. However, this does not appear to ‘sound’ the same as reported.
Longer beeps are sometimes associated with radar sweeps and result in VHF interference.

[Funnel Cloud]

I have also noticed these beeps for several years now and still don't know what it is. I do know it only ever seems to happen in France, so there must be a reason for it.

I hope somebody knows the answer!

Regards,
FC

[WaterMeths]

I have heard these bleeps over Scottish FIR too over the years, they sound like some sort of carrier test tone to me...just putting my old "telecom" head on there for a moment. When I hear one these days, like you say over France - I expect two to three more over a minute span, and I'm usually not disappointed !!

[airseb]

i've been told that these beeps relate to the opening and closing of atc sectors. when a new sector is opened due to an increse in traffic load, a new vhffrequency is designated to it. and there comes a bleep to check that it's emitting and recieving.
maybe an atco to shed his light

seb

[Caudillo]

These French beeps got me wondering a while back and I was told it was their military radar. Might be, although they don't sound like what I've come to know as a radar being pointed at you - ie at Aberdeen.

On a related point, I quite often hear at the end of transmissions - both from ground and airbourne stations - a short very sharp sort of beep plus interference, different from the French stuff - does that ring any bells?

[overstress]

Airseb has the right answer, I think, caused by ATC fiddling with 'bandboxing'

[stator vane]

also related to that, i think,

is when i hear ATC tell an aircraft to contact them on a frequency that i am on now, and i can hear the other aircraft's reply, apparently on a different frequency, then a few seconds later, i hear the same aircraft checking in on my frequency.

the only think i can think-is that when ATC combine frequencies/sectors, the transmissions from the aircraft on the other frequencies are co-broadcast on all the currently joined frequencies.

more frequent in the dark late hours which would make sense with the tendency to combine sectors when traffic is lower.

it does seem to be more prevalent over france more than anywhere else i have flown. as well as garbage noise on guard appears to be a french event more so than other countries. perhaps a function of combined sectors as well.