> "Tim S." <[EMAIL PROTECTED]> wrote: > Pretty sure I know the answer to this. > But can a transmitter keying into a > duplexer that's detuned cause intermod > interference?
It sure can. A local area repeater in Michigan on 146.64/04 was causing interference, and was being heard, on a 146.68/08 repeater about 60 miles away. Someone, un-authorized, had made adjustments to the duplexer (Tx out into duplexer 40 W, power out of duplexer 3 Watt). The picture on the spectrum analyzer looked like a Christmas tree as the PA was going into all kinds of spurious oscillations. After retuning with proper equipment (vector network analyzer) all interference stopped and the TX was clean again. An isolator will do the trick to protect the PA and reduce the chance of spurious oscillation and inter-modulation but it will not cure the problem. Retune the duplexer ASAP with proper equipment. 73, Tony VE3DWI --- Outgoing mail is certified Virus Free. Checked by AVG anti-virus system (http://www.grisoft.com). Version: 6.0.742 / Virus Database: 495 - Release Date: 19/08/2004 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/
