Radio interference
 

I am having some problems with radio interference when recording on my Korg D3200 mixer. I have good mics, new XLR cables and am plugging into grounded outlets. It is a local AM radio station that has the transmitter about 2 miles away. I have also had problems at another location much further away (probably another station). It seems to be related to the XLR cables. I plugged a Sony ECM 44b lav directly in to the mixer and did not have any radio pickup at all. I thought that XLR cables were shielded to prevent this problem. Is there anything that I can do about this? I cannot afford to have problems in the field.

Regards,
Jerry

Jerry,
Neutrik EMC Series connectors may help.

There are some good papers on RF problems and dealing with them on Jim Browns site. http://www.audiosystemsgroup.com/
Look at the papers on pin 1 problems and understanding RF interference.


Sam Gates

So-called "quad" xlr cables may help. They resist RF somewhat better than a standard cable.

Most of the major manufacturers have them, they have 4 conductors (plus shield), in two twisted pairs that are then twisted around each other. Then each pair goes to a pin. This is a lousy explanation, you'd find more info at http://canare.com/files/Cat11_p35.pdf.

If you go the Quad route, be aware that they wear out much faster than other cables, due to the fine/thin strands. I thought I was losing my mind a few years back when having problems with a couple cables. Fred Ginsberg took out a knife and showed me where the problem lay. Coiling/uncoiling the quads will cause early failure. But they are better in bad RF situations, supposedly.