Low level buzz on Radio 4 FM.

[Pioneer4]

Hi, Not sure if this is the correct place for this query or anyone is able to offer advice but here’s the thing. For the last few months, only sometimes at first, but now all the time there is a background buzz on Radio 4 fm. There is also some degree of low level noise on Radio 1,2 and 3 but 4 is the most affected. The noise is only audible in Stereo and silent in Mono. No other fm stations have this noise with local commercial station (Peak fm), Hallam and bbc radio Sheffield all noise free.

I’ve tried several fm tuners in my audio system and they all exhibit the same noise problem. I’m using a loft mounted half wave dipole, live 3 miles from the transmitter (Unstone, Derbyshire) and receive all stations at a 90% indicated signal strength. As other local stations sound perfectly clear it’s pointing towards the local mast - excuse the pun. Although having checked the mast online there are no advised issues.

As a regular listener to ye olde fm stereo radio 4 it’s becoming an issue unless mono is selected which defeats the beauty of this way of listening.

Any thoughts anyone ?

David.

[buggies]

Ideas only - -
try a portable receiver (mobile phone?) - take it for a walk
try a piece of wire poked in the tuner aerial socket - move it around to get hiss-free signal
try an attenuator in the aerial lead.

[Cathovisor]

Can you hear it on a portable or a car radio?

If so, it might be worth getting in touch with the distribution arm of the BBC. I say this because several years ago I noticed there was a low-level whistle on Radio 4 which was independent of receiver but disappeared when I got towards London on my way to work. Having provided the BBC with a recording of the noise, Arqiva were able to pinpoint it to a faulty stereo encoder at the local transmitter which was also being picked up by a rebroadcast link.

[paulsherwin]

Either there is interference within your house, or there is a transmission fault at the Unstone (Chesterfield) transmitter, which is only a weedy relay. Can you get a R4 signal from somewhere else - Holme Moss, or even Sutton Coldfield?

R4 HM is 93.7MHz.

[Pioneer4]

Thanks for the suggestions.

Unfortunately I’m unable to receive r4 from the two alternative transmitters at a strong enough signal strength to confirm Unstone is at fault as the hash masks the low level buzzing from being discernible.

I’d be surprised if the buzz is being caused by interference in my house as surely the other stations of equal signal strength would also have the noise yet they are all crystal clear. I’m becoming more inclined to lay the blame with the Unstone mast as all the other stations are being received directly from their own transmitters.

Excuse my ignorance but does a received fm broadcast need to have a certain signal quality as well as signal strength ? I receive all bbc and local commercial radio at nearly full on the signal strength meters on all my tuners and apart from the Unstone stations buzz they all sound perfect.

However, tomorrow I will do as suggested regarding trying my car fm radio to see if the noise is present and report back. If the car radio has the low level buzz on r4 can anyone advise how to contact the relevant authority ? And is there anyone else having the same issue in my area ?

David.

[Cathovisor]

Originally Posted by paulsherwin

Either there is interference within your house, or there is a transmission fault at the Unstone (Chesterfield) transmitter, which is only a weedy relay.

The problem I had when I was fault-finding. A transmitter near Bedford is a RBR of Morborne so my journey to work took in Morborne -> Bedford -> Wrotham.

[Nickthedentist]

Originally Posted by Pioneer44

Excuse my ignorance but does a received fm broadcast need to have a certain signal quality as well as signal strength ?

Yes, an example of poor quality being multipath distortion, I suppose. But nothing that would cause buzzing IMHO.

[agardiner]

Yes the signal quality is important. The stereo difference part of the signal is AM modulated, so is much more susceptible to interference. In an ideal world you would take a portable receiver out of your house to eliminate any sources of interference, but it would of course need to be a stereo unit. A faulty mobile phone charge, LED light bulb etc could cause your problem.

Perhaps try switching off all lights, your wi-fi router and anything powered by a 'wall wart' type adapter, and see if the problem remains. If so, report to the BBC so it can be checked.

[Nickthedentist]

Please do report back on the car radio's performance. Otherwise this is all speculation

[Nuvistor]

The BBC help pages suggest that LED lights can cause buzzing.

[Nickthedentist]

True, but it would be unlikely to affect just one station.

[Nuvistor]

It seems to be a problem in the lower end of Band 2 so could be peaking on Radio 4. It’s guess work at the moment but it’s been suggested to switch off as much as possible in the house.
I am really interested to know the cause, probably we all are.

[Cathovisor]

Originally Posted by agardiner

If so, report to the BBC so it can be checked.

A caveat here; the OP may have to go a bit further into the BBC than 'Reception Advice' to deal with this. I know I had to.

[Pioneer4]

Well this is quite strange.....

Following posting on Sunday evening I switched off all the house circuits apart from the ring supplying the audio equipment unplugging all items except the FM receiver yet the buzz remained.

However, Monday afternoon the car stereo was tuned to R4 93.4Mhz only to discover no buzz whatsoever. Then went indoors and listened to R4 playing The Archers, which is perfect fare for highlighting any spurious noise, and there was no buzz there either The abrupt cessation of the noise after several months coming so shortly after posting on this forum must be coincidental with the most likely reason being atmospherics ?

After looking into the effects of weather on FM & AM transmissions (and remembering well the phenomenons caused by atmospherics to my 27Mhz AM transceiver back in the late 70`s) would it possible that the modulated part of the R4 Stereo broadcast signal has been affected ? The buzzing noise originally began at the end of the summer slowly getting more obvious until now when the local barometric pressure has risen greatly to 1040 Millibars since Monday ?? And if this was the reason why was it only Unstone transmitted signals that were affected ? Or is it some other reason completely ? It will be interesting to tune to R4 when the weather deteriorates.

I appreciate the knowledgeable and informed replies to the original post and find it encouraging that there are still people willing to help. For the first time in a few weeks I`m able to fully enjoy R4 in Stereo without the tiresome buzz and long may it continue.

My listening receiver, being a Pioneer SX5580, may not be classed as vintage just yet but still sounds very enjoyable tuned to BBC radio in Stereo.....the youngsters really don`t know what they`re missing if they`ve never heard a decent quality FM broadcast, the highest quality FM I`ve ever had the pleasure of listening to being a Harman Kardon Citation 18 tuner many years ago (one of which I`m still trying to find) Long live FM.

Any thoughts ?

David.

[Nuvistor]

Glad it’s sorted, perhaps we will never know the cause.

[paulsherwin]

It's most likely that there was indeed a transmission fault which Arqiva have now fixed. Your posting in this forum may have had some effect - some Arqiva employees do vist it.

[agardiner]

Whatever the cause, I am glad you are interference free again.

[Pioneer4]

Hi,

As a follow up to the Unstone transmitter buzz I have to report it has not returned 🙂.

So I’m inclined to believe Paul’s theory that an Arqiva employee was made aware of the issue while reading this forum……….,if he/she would like to come forward and confirm this it would be appreciated.

Hopefully the problem doesn’t return and perfect reception continues 👍.

David.