[Phil Allison[_4_]]

mcp6453 wrote:


Here's what I've found. The problem is definitely EMI. There's a cell
phone tower less than a block away.


** Well out of range then.


Moving the mic in the room can
exacerbate or eliminate the noise. Unfortunately there is not a
practical position that will eliminate it.


** So it's not the cell tower.


So, I took an RE15, RE18,
MD421U, and Beta 87A. All of the mics eliminated the noise although
there was still a little with the 421.


** The RE15, RE18 and MD421 all have hum bucking coils, while the 87a is a condenser mic.



Upon further research, I discovered that the PR40 (my favorite
spoken-word mic) and the RE20/27 have humbucking coils. With God as my
witness (ala WKRP), after all this time, I never knew about the coils.
How I overlooked it escapes me.


** The others escaped you too.


What this experience has taught me is
that it is a REALLY good idea to use mics with humbucking coils whenever
possible - particularly in unfamiliar territory. Since I almost always
use a PR40, I've avoided the problem in most cases. However, the PR40 is
very large for on-camera use, so I'm thinking about a couple of RE16s,
unless someone can suggest less expensive alternatives that also include
effective humbucking coils.


** Condenser mics do not need such coils.

There is a big hum field in or near that office room you have yet to uncover.



..... Phil