Cardo Freecom 4 - RDS?

Over the last month or so, while riding to work and listening to the radio, every time I go past a certain inner London (chiswick cut through) I get awesome steroe sound. I mean the sound generally is good with the JBL speakers but always at the same 50m stretch I suddenly get what could only be described as fantastic stereo sound. Is this an RDS thing? My route winds through busy suburbia to the M4. I only get this boost at the same point for limited time. The other times its in stereo I think, but just not sublime stereo. Ideas? Same route, same headset, every time I pass, no radio mast that I notice, speed irrelevant

It’s nothing to do with RDS. Except a likely RDS performing an auto frequency selection to a stronger transmitter. RDS provides the ability for broadcasters to overlay (underlays) data on a sub carrier which can be used to control or deliver information to your radio.
Perhaps a case of the rest of the time you aren’t receiving a strong signal, the Cardo is doing it’s job and self defining to mono audio. At the point you experience that quality you take about you receive the signal from another transmitter, if you are on the fringe of the previous one, and then you have a true stereo signal.

The Cardo is relying on a small antenna inside the helmet to collect the signal and work it’s magic.


Where is it happening and which station.

Cyber said:

It’s nothing to do with RDS. Except a likely RDS performing an auto frequency selection to a stronger transmitter. RDS provides the ability for broadcasters to overlay (underlays) data on a sub carrier which can be used to control or deliver information to your radio.
Perhaps a case of the rest of the time you aren’t receiving a strong signal, the Cardo is doing it’s job and self defining to mono audio. At the point you experience that quality you take about you receive the signal from another transmitter, if you are on the fringe of the previous one, and then you have a true stereo signal.

The Cardo is relying on a small antenna inside the helmet to collect the signal and work it’s magic.


Where is it happening and which station.

Click to expand...

Here https://www.google.co.uk/maps/@51.4811765,-0.2841461,18z?hl=en
Its happened on magic fm and on Absolute radio. I agree it is not the headset doing anything wrong as it is always in same place but just wish I had surreal sound always!

So this is the predicted radiated pattern for Absolute
http://a-bc.co.uk/MCA/AL000173-TQ33947122.html

And this for Magic http://a-bc.co.uk/MCA/AL000051-TQ33236961.html

Looks like your safely into a radiated pattern and they are two quite different transmitter sites.

The two frequencies are separated by 400Khz, the min being 200Khz so no issues there.

My guess will be the some local topology which means your experience is an effect of knife edge diffraction, perhaps filtering is not what it could be in the Cardo, maybe an industrialist making use of some of the local radio spectrum.

Doesn’t answer the question but too many variables.

We go (did go) to Spain several times a year. There due to the topo the local English speaking radio station has 6 transmitter sites for a relatively small area. Driving at the cusp of the signal you can sometimes receive two different transmitter sites, not at the same time but to the ear it appears it is. Sometimes there is a half second delay due to the “wire” connection to the transmitter site but the effect it creates is very odd.