FM signal problem

[doversoul1]

This sounds bizarre but I seem to have become some kind of an anti-conductor. Not the kind Ariosto is expert in but in an electric sense. Maybe I’m just ignorant of some basic physics. I wonder if experts on these boards can enlighten me.

Normally, I have very good FM reception but I have noticed in the last few months, Radio 3 signal disappears from time to time. The thing is, this seems to be something to do with my movement. It cuts off when I move to this spot in the room and comes back when I step back to that spot, or sometimes it cuts off when I put my hand close to the receiver/tuner to turn the volume up or down, and when I move my hand away, it comes back. I have tried to see if there are any patterns of my movement that correspond with this on-and-off but so far have not found anything like a pattern (imagine me dancing around the room to see if I can remote control my radio with a wave of my hand…). Even more bizarrely, this mostly happens on weekend. I work from home so it’s not that I notice more on weekends. I don’t know if this happens on Radio4 as I listen to it on my transistor radio.

Is there (there must be) a perfectly logical explanation?

[Ariosto]

This sounds bizarre but I seem to have become some kind of an anti-conductor. Not the kind Ariosto is expert in but in an electric sense. Maybe I’m just ignorant of some basic physics. I wonder if experts on these boards can enlighten me.

Normally, I have very good FM reception but I have noticed in the last few months, Radio 3 signal disappears from time to time. The thing is, this seems to be something to do with my movement. It cuts off when I move to this spot in the room and comes back when I step back to that spot, or sometimes it cuts off when I put my hand close to the receiver/tuner to turn the volume up or down, and when I move my hand away, it comes back. I have tried to see if there are any patterns of my movement that correspond with this on-and-off but so far have not found anything like a pattern (imagine me dancing around the room to see if I can remote control my radio with a wave of my hand…). Even more bizarrely, this mostly happens on weekend. I work from home so it’s not that I notice more on weekends. I don’t know if this happens on Radio4 as I listen to it on my transistor radio.

Is there (there must be) a perfectly logical explanation?

It's caused by a lightning conductor. One who grabs his fee in a split second and clears off without giving the band any signals. He only appears again when he can make a quick killing and disapear with the signal and a big fat cheque ...

[salymap]

My kitchen radio, a little Sony FM mono set does that doversoul. I have to keep the set at an angle on the corner of the table but if I cross the kitchen to fetch something the sound breaks up. And like yours, it doesn't do it all the time.

[mangerton]

Radio waves are strange things. VHF FM* radio waves even more so. I experience similar problems. I adjust the aerial on my portable radio till it sounds fine. Take my hand away and the sound breaks up.

Reflections, standing waves, interference of one sort or another all affect VHF FM reception. It's why the once excellent** BBC Engineering Information Department couldn't give much help until and unless you had a VHF FM aerial properly mounted.

* VHF FM defines the frequency and the method of modulation. The former is the point at issue here.

** I'm talking 40 or so years ago, before beancounters were heard of, when they were very helpful to a young mangerton who lived in a difficult reception area and was very keen to get stereo reception.

[Don Petter]

ds,

As others have said, VHF reception has always been subject to such effects.

If it is the first time you have experienced it, I would think it implies some change in the link from transmitter to your set.

If it isn't down to the source, or atmospheric conditions, which can affect such things, perhaps there has been some change in your aerial connections. (A dirty joint or plug and socket somewhere?)

[BetweenTheStaves]

It's all part of the dastardly plan to force us over to DAB. They are going to gradually deteriorate the FM service until we get fed up and go out and buy a DAB.

Seriously, it could be transmitter work. There is a website I have bookmarked somewhere or other that gives this information. Do you know which transmitter you receive from?

[Serial_Apologist]

I used to have this problem with Radio 3 when I lived in Bristol. I wondered then if it had anything to do with atmospheric conditions: the problem seemed worse when barometric pressure was high.

S-A

[salymap]

It's all part of the dastardly plan to force us over to DAB. They are going to gradually deteriorate the FM service until we get fed up and go out and buy a DAB.

Seriously, it could be transmitter work. There is a website I have bookmarked somewhere or other that gives this information. Do you know which transmitter you receive from?

I think I receive from Crystal Palace. Is that any help?

[Segilla]

Periodic distortion etc as you describe has been a feature of FM ever since I bought one of the first on sale c. 1956, together with its 'experimental aerial'.
The sound was so much better than AM - when it was working well.

A few days ago I started to have unreliable reception. I wonder if sunspot activity has any bearing on this?

[doversoul1]

Thank you all for your information (and interference, Ariosto ). I am afraid I have no idea where the transmitter is but I’ll find out. What puzzles me is:

1. I have had this receiver/tuner for some ten years but never before had this problem.

2. It is not the kind of poor reception or interference but the break up is definitely to do with my movement.

3. The receiver generally works perfectly well, and even when the signal cuts off, when it comes back the sound quality is not affected.

Well, at least it looks as if I haven’t gone quite mad, which is a relief.

[Serial_Apologist]

Thank you all for your information (and interference, Ariosto ). I am afraid I have no idea where the transmitter is but I’ll find out. What puzzles me is:

1. I have had this receiver/tuner for some ten years but never before had this problem.

2. It is not the kind of poor reception or interference but the break up is definitely to do with my movement.

3. The receiver generally works perfectly well, and even when the signal cuts off, when it comes back the sound quality is not affected.

Well, at least it looks as if I haven’t gone quite mad, which is a relief.

Er - possibly delicate question this, doversoul - you haven't perchance put on weight recently, have you?

[doversoul1]

Er - possibly delicate question this, doversoul - you haven't perchance put on weight recently, have you?

All my old clothes still fit me comfortably, so I suppose the new potatoes from the garden haven’t made very much difference. But what’s the connection?!

[Serial_Apologist]

Erm - things getting in the way of the signal???

[Ferretfancy]

Most sets or tuners have an automatic frequency control that keeps them in tune. If yours has drifted, possibly from component ageing that might be a reason for your problem. If you don't have an outside aerial, but an antenna on the set, have a look at a map in your area to find the approximate bearing of the transmitter, and extend the antenna
horizontally facing that direction. It's also a good plan to place the receiver so that it does not lie between you and the transmitter.My set in the kitchen used to make loud scrunching noises until I changed the Aerial position.

[Serial_Apologist]

My Bristolian friends told me that my problem was due to the aerial I lived in