John, Are you using a Delta-44? If so I would do just as Eric says and run your mic directly to INS/3 on the breakout box. You can run a balanced or unbalanced mic to that jack with the proper plug. It converts it to unbal soon as it goes into the box anyway. You might also consider getting a pre-amp if that particular mic does not have a lot of output. The Behringer UB802 is a simple mixer with adjustable mic pre and takes balanced or unbalanced mics and outputs to either as well. I think it sells for around $50. I've used one before and it worked perfectly, no hummmmm!
Good Luck, Brian W5AMI On 7/12/06, FlexRadio - Eric <[EMAIL PROTECTED]> wrote: > John, > > It sounds like you may need to isolate the microphone ground from the > chassis ground. Having these connected can cause a ground loop that can > cause strange echoes with distortion (grows with higher power) as well as > hum. Note that the pinout in the Operating Manual for the 8-pin mic > connector has these two on separate pins for this reason. > > The need for this is because the soundcard has it's own ground and this is > ultimately where the microphone signal is headed. If possible, try to run > the microphone directly to the soundcard and see if that improves things as > this will ensure no ground loop exists between the microphone input and the > chassis. > > > Eric Wachsmann > FlexRadio Systems > > > -----Original Message----- > > From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED] > > radio.biz] On Behalf Of John Hansen > > Sent: Wednesday, July 12, 2006 6:58 PM > > To: [email protected] > > Subject: [Flexradio] More on Audio Problem > > > > Upon further reflection, the problem is not just a hum. There is a weak > > hum in there, but there is also what sounds like feedback.... it goes > > thumpa thumpa thumpa.... however I do have the monitor off. It > > continues even when I turn the radio off that I was using to monitor > > it.... at that point I can hear if very weakly thumping in my monitor > > speaker (even though it's on mute). When I turn the mic gain down to 0 > > it has no effect, but if I lower my power to a setting under 30 it does > > go away. I do hope this isn't an indication that RF is getting into > > this because with all these wires running around here it's going to be a > > mess to straighten out. BTW, I do not have this interference on CW or > > on the digital modes using the VAC. > > > > John > > > > > > _______________________________________________ > > FlexRadio mailing list > > [email protected] > > http://mail.flex-radio.biz/mailman/listinfo/flexradio_flex-radio.biz > > Archive Link: http://www.mail-archive.com/flexradio%40flex-radio.biz/ > > FlexRadio Homepage: http://www.flex-radio.com > > > _______________________________________________ > FlexRadio mailing list > [email protected] > http://mail.flex-radio.biz/mailman/listinfo/flexradio_flex-radio.biz > Archive Link: http://www.mail-archive.com/flexradio%40flex-radio.biz/ > FlexRadio Homepage: http://www.flex-radio.com > -- "There is nothing more uncommon than common sense." -- Frank Lloyd Wright _______________________________________________ FlexRadio mailing list [email protected] http://mail.flex-radio.biz/mailman/listinfo/flexradio_flex-radio.biz Archive Link: http://www.mail-archive.com/flexradio%40flex-radio.biz/ FlexRadio Homepage: http://www.flex-radio.com
