On Fri, 25 Apr 2003 15:38:10 +1000, "Hughy" <antispam@spamkiller.net> wrote:

>"Neuman - Ruether" <d_ruether@hotmail.com> wrote in message

>news:3ea9f0e5.7782891@newsstand.cit.cornell.edu...

>> I have had no problems with RFI, but we have no TV

>> broadcasting here (I use two 680-1k ohm resistors and

>> a 100MFD cap in my pad...).

>Your 100 uF cap is a DC blocker, which is unnecessary because the MKE300

>already incorporates a series capacitor for this purpose. You can check this

>quite easily - just connect a digimeter (or other high input Z measuring

>device) on DC volts, low range, across the output miniplug. Turn the MKE300

>on. You'll see somewhere around + or - 0.5 volts appear briefly, which

>gradually drops over time to zero (the internal cap is now charging through

>your digimeter). With the meter still connected, now switch off the mike.

>You'll instantly see a voltage spike of *opposite* polarity (the internal

>cap is now discharging).

Yes - but the pad is not used just for the MKE-300s...

I use some other gear connected to the same input,

and the DC voltage can be a problem with some of

this...

>Your pad is an "L" pad, and ignoring the series resistance of the capacitor,

>provides a terminating Z of around 1.5K (when it is connected to the VX2000

>input). This is below the Sennheiser recommended minimum terminating Z. I

>suspect the effect of the reduced Z would be that your frequency response

>may not be quite as flat as it was designed to be, but if the system sounds

>OK then you can't be losing much. I'm anything but sure about the last

>sentence, I don't know the characteristics of the VX pre-amp input cctry.

>Maybe someone else can confirm or correct this ???

Actually, a 10:1 (or greater) impedance differential

is unnecessary, assuming I'm not going for greatest

sensitivity (and with a pad, I'm not...;-), and the

slight "mismatch" I use will have no *noticeable*

effect. The mic should also work fine into the

more common 600 ohms mic preamp input impedance...

>> I've pretty much decided to switch from wireless

>> to MiniDisk this year - wireless has had too

>> many problems with RFI here in the last couple

>> of years (EVERYONE walks around with a cel phone

>> stuck to their ear...! ;-).

>I have a second lav on the groom, feeding a (VHF) Azden. It's actually less

>work to use that in post (it feeds 2nd cam XL1 audio 2) because I can

>download all four XL1 audio tracks simultaneously with the video (DVStorm).

>The MiniDisk requires an extra download operation, but it's there if we need

>it (and we need it more often these days as the spectrum gets noisier).

>Regards,

>Hughy.

I also have been using the cheap Azden - successfully

until about two years ago. Now all three have "swish"

interference noises in the recordings. I prefer the

convenience of the wireless (I used two per camera),

but dealing with the noise pick-up is not fun (and I

have three cheap Mini-Disk recorders and suitable mics

for them already, so spending $500 on the recommended

Sennheiser Evolution 100 [for just one] is unlikely

to happen soon...;-).