Getting rid of FM radio interference

[a.g.]

I have an ongoing battle trying to get optimum FM signal with my Denon TU-260LmkII tuner. I get a reasonable signal until I switch on my old 21" CRT monitor, at which point everything other than the local commercial station gets crackly. The tuner is quite near the monitor and there's not much I can do to reposition it until I buy a rack.

So, is there any easy way of reducing EMI? Putting tin foil on the inside of the tuner's casing or something? Using a roof aerial makes no difference.

 

[drummerman]

[quote user="a.g."]
I have an ongoing battle trying to get optimum FM signal with my Denon TU-260LmkII tuner. I get a reasonable signal until I switch on my old 21" CRT monitor, at which point everything other than the local commercial station gets crackly. The tuner is quite near the monitor and there's not much I can do to reposition it until I buy a rack.

So, is there any easy way of reducing EMI? Putting tin foil on the inside of the tuner's casing or something? Using a roof aerial makes no difference.

[/quote]

A bit drastic if all thats needed is abit of space between monitor/tuner. Get a s/h rack for a tenner or a longer interconnect to move the tuner away bearing in mind that your other components ie amp/cd are probably near the monitor too and are susceptible to interference as well.

You can try ferrite rings around cables etc but I doubt it will completely solve what really is an easily solveable problem.

 

[a.g.]

Unfortunately, moving components is not a viable option for cabling and ergonomic reasons. I have a ferrite ring around the aerial cable but it doesn't do much, and I don't know if I can squeeze one through the power cable. I don't mind drastic action if it means I'm going to get better reception.

 

[Tear Drop]

Ferrite rings do work - you must place them on the mains cable to your tuner, not the aerial cable. I have done this myself after seeing it demoed in a lecture a number of years back. I was shocked at first that it works, and so effectively, but work it does. Three ferrites seems to be the optimum number (adding more doesn't do anything else in my experience). Make sure they clamp the cable tightly. Have a look at Maplin or RS Components for them, they are fairly cheap.

 

[a.g.]

Interesting, thankyou Tear Drop. I have a large collection of slip-on ones which I believe are designed to be tied to the cable as part of a knot, so I may have a play around with them. I am thinking about an upgraded power cable, but I believe those are a cause of disagreement on this forum!

 

[Tear Drop]

A well shielded mains cable with at least one ferrite clamp on each end would pretty much eliminate any interference now or in the future for your tuner.

 

[a.g.]

Well I'll certainly take your word for it and look into it. Thanks for the help, I appreciate it

 

[a.g.]

You weren't joking, were you? I bought a Black Rhodium cable on eBay and the reception has *definitely* improved (I'm even getting RDS data on stations which I wasn't before) and also, perhaps more pleasingly, the sound quality has improved by a huge amount. I totally recommend a cable upgrade to anyone who uses a tuner on even a semi-regular basis.

 

[Andrew Everard]

So there's one for the 'mains cables can't possibly make a difference' people...

 

[fatboyslimfast]

Always good to hear of actual real-world improvements (and I'm a cable sceptic)...

 

[Tear Drop]

Glad to hear it's getting better! Just make sure you get the ferrites too for further improvements in FM reception.

 

[a.g.]

It came with a loose ferrite ring around the cable, so I've just wrapped some tape around the cable in order for the ring to be a tight fit and that seems to have made a difference. I might have to get some more from an electronics shop.