I would attempt to say a noise cancelling mic. something like a SHURE Comm. Mic. or something like they used in Avaition the center slot style forget those ugly cheap 11M. mikes ( sledge hammer anyone ? ) may help the road noise.
Mark Holman [EMAIL PROTECTED] http://www.ab8ru.org ----- Original Message ----- From: "Chuck Kelsey" <[EMAIL PROTECTED]> To: <[email protected]> Sent: Thursday, April 14, 2005 5:50 PM Subject: Re: [Repeater-Builder] Microphone Gain and Deviation > > I had a friend who refused to get any closer to the microphone than 12 ". > He > was real difficult to understand due to the low audio level that resulted. > We turned up the gain in his mobile, but it was still a bit of a problem > since it then increased the road noise. > > Chuck > WB2EDV > > > ----- Original Message ----- > From: Steve Bosshard (NU5D) > To: [email protected] > Sent: Thursday, April 14, 2005 5:43 PM > Subject: [Repeater-Builder] Microphone Gain and Deviation > > > > Best answer I have found for soft spoken folks is the little mic preamp > board used in some of the old GE Phoenix and MVS radios. Little single > stage amp that operated from bias on the mic line. > I usually set the deviation limit for voice at 4.0 Khz. And allow a little > for tone/dcg. > NEVER EVER USE THE TRANSMITTER DEVIATION CONTROL TO MAKE UP FOR LACKING > MIC > GAIN. A soft spoken person may need a mic preamp, or a more sensitive > microphone. Beware of excessive mic gain competing with ctcss and causing > drop or talk down. A small swamping resistor might be in order. Wish > Helper still made the modulation density meter. > SOP is to set a tone gen at around 50 mv or enough to fully modulate the > transmitter, and then set the deviation limit to around +/- 4.0 Khz @ 1000 > Hz. Tone. Using the IDC to boost mic gain will lead to overmodulation and > clipping out of the pass band of the receiver, not to mention the joy you > will bring to your adjacent channel neighbors. > 2 cents and 30 years, > Steve > > > > > > > > > Yahoo! Groups Links > > > > > > > > Yahoo! Groups Links <*> To visit your group on the web, go to: http://groups.yahoo.com/group/Repeater-Builder/ <*> To unsubscribe from this group, send an email to: [EMAIL PROTECTED] <*> Your use of Yahoo! Groups is subject to: http://docs.yahoo.com/info/terms/
