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Phono stage picking up radio signals?

The strangest thing happened this evening. I just hooked up my Whest phono stage and as I was letting it warm up I turned up the volume slightly to check the noise level and noticed a strange noise coming from the speakers. At first I thought it was a ground loop hum or some feedback, but when I put my ear to the speaker I distinctly heard music. I turned up the volume a bit and to my surprise I could hear and identify the song playing, followed shortly after by DJ banter. It was obvious I was picking up a radio station, but I don't have a tuner or any other radio device in the home. Can anyone give me a clue as to what might be going on.
clio09
clio09 OP
3,360 posts
 
Nsgarch,

Thanks for the comments. I have one question. Can I connect a wire from the TT lugnut to the phono preamp lugnut, then connect the tonearm cable ground wire to the phono preamp lugnut as well?
arihell
1 posts
 
Here is one question I asked the constructor of the Whest PS.20, James Henriot, before I bought the unit:

I have heard some rumours that the PS.20 is sensible to RFI signals.
Since I sometimes have problems with radio signals, I just wonder if this is correct.

Henriot's answer:
The rumours are right but we rectified the problem about 4 months ago and it was found that our loading supplier made the plugs incorrectly.

This was one month ago, and I have had no RFI problems with this unit.
clio09 OP
3,360 posts
 
The unit I have was manufactured in March 05, so I probably have one of the units you are referencing. I will probably ask him for a new set of plugs based on this to see what difference they make. Thanks for the information.
kel34
64 posts
 
I am not familar with your phonostage so this reply may be redundant but if it has tubes try replacing them.

Some tubes play radio stations and others don't I don't know why but thats the way it is.

If that doesn't work then you have a grounding problem in your arm or shielding problem in your system somewhere.

One thing you can try is installing ferrite beads over the inputs of the phono. They must be inside the preamp to be effective. They don't work went put inside interconect RCA's.
clio09 OP
3,360 posts
 
Kel34,

Thanks for the response. It so happens the tube phono stage works fine (Cary PH-301), it's the solid state one that is causing problems. I am looking into ari-hell's suggestion as that is the cheapest way to go for now. If that doesn't work I'll try a pair of shielded ICs, as Nordost are not shielded. If all that doesn't work I have two more phono stages coming that I was going to compare against the Whest and if they work then the Whest is pobably out and I'll choose between the Hagerman and Decware.
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