Chris,
If you are using balanced line and getting RFI, something is out of
balanced, most likely the latter line. You must be careful that the
lengths of both lines are exactly the same, and that includes the
antenna. And ANY metal objects close to either side will throw it out
of balance. The whole ideal of balance lines is the word balanced,
exactly the same and the RF will be canceled out. These things have
to be planned very carefully. I have run balanced here and had no RF
showing on my field strength meter, if it does, there is a problem.
73,
Dudley
WA5QPZ
Chris seeber wrote:
Hi Carmine,
I was wondering about the RFI issue myself. It may be a problem here,
as I do have a fair amount of RFI in here. I'm using 450 ohm window
line connected to baluns in the shack for the antenna feeds. I plan on
moving the baluns outside and running coax in, but I was thinking of
waiting until the snow melts. I'll use some ferrites on the audio line.
Hopefully they'll do the trick. I have terrible RFI problems on my
Ethernet connection - in both directions (that is hash/birdies into the
receiver and data errors from the transmitter). I need to get some good
ferrites for that connection as well.
But its fun trying to figure out how to make all this work well.
Chris,
KA1GEU
-----Original Message-----
From: Carmine Iannace [mailto:mindaugas2...@yahoo.com]
Sent: Wednesday, January 28, 2009 3:03 PM
To: flexradio@flex-radio.biz; Chris seeber
Subject: Re: [Flexradio] Balanced vs. unbalanced microphone inputs
I would think the audio quality difference will be incomprehensible
barring a ground loop or a level mismatch.
Please bear in mind that balanced audio circuits should have a
considerably higher immunity to strong RF fields (RFI) than a typical
"consumer grade" unbalanced, coax like shielded audio- a.k.a. "RCA or
phono type" connections.
Carmine
W1EQX
_______________________________________________
FlexRadio Systems Mailing List
FlexRadio@flex-radio.biz
http://mail.flex-radio.biz/mailman/listinfo/flexradio_flex-radio.biz
Archives: http://www.mail-archive.com/flexradio%40flex-radio.biz/
Knowledge Base: http://kc.flex-radio.com/ Homepage: http://www.flex-radio.com/
_______________________________________________
FlexRadio Systems Mailing List
FlexRadio@flex-radio.biz
http://mail.flex-radio.biz/mailman/listinfo/flexradio_flex-radio.biz
Archives: http://www.mail-archive.com/flexradio%40flex-radio.biz/
Knowledge Base: http://kc.flex-radio.com/ Homepage: http://www.flex-radio.com/
