Dear Eric, Thank you for your mail.
Yes, we found that the interconnect T-Join between two system is heated up. Could we just cool down the T-Join for there is other way to solve this issue? Best Regards, Kent --- On Wed, 10/3/10, Eric Lowell <elowell9...@yahoo.com> wrote: From: Eric Lowell <elowell9...@yahoo.com> Subject: Re: [Repeater-Builder] Noise Level on a Duplexer To: Repeater-Builder@yahoogroups.com Date: Wednesday, 10 March, 2010, 8:54 PM Kent, I have seen this sort of problem before in a simaler application. I believe that your duplexer may have a bad internal connection, possibly at a fingerstock contact. In my case the problem was solved by replacing the duplexer. I believe the problem was caused by tuning the duplexer under power rather than with a network analyser. This occured many years ago, so my memory may be faulty. Best Regards de Eric (W1EL) Eric Lowell Eastern Maine Electronics Inc. 48 Loon Road Wesley ME 04686 eme....@starband. net www.satnetmaine. com 207-210-7469 From: Kent Chong <kentchongkm@ yahoo.com. sg> To: Repeater-Builder@ yahoogroups. com Sent: Tue, March 9, 2010 10:31:30 AM Subject: Re: [Repeater-Builder] Noise Level on a Duplexer Dear Joe, Yes, we have observed the signal with a spectrum analyser. It is a broadband noise covering our entire TETRA band. Yes, the transmitter is keyed up continually. Regarding oscillation, what circuitry will develop the oscillation in 3 days? We are thinking about the heat problem too, as heat may be developed overtime. Best Regards, Kent --- On Tue, 9/3/10, Joe <k1ike_m...@snet. net> wrote: From: Joe <k1ike_m...@snet. net> Subject: Re: [Repeater-Builder] Noise Level on a Duplexer To: Repeater-Builder@ yahoogroups. com Date: Tuesday, 9 March, 2010, 8:52 PM Hello Kent, Have you looked at the noise on a spectrum analyzer? Is is broadbanded noise, or is it just on your receiver frequencies? If it is only on specific frequencies, is it frequency stable or does it drift around? Also, do any of your transmitters stay constantly keyed up? I'm wondering if something external to your system is oscillating. Your signals may be causing it to go into self-oscillation. When you shut your system off it stops. This is just a guess right now. 73, Joe, K1ike > > > <http://sg.rd. yahoo.com/ sg/mail/domainch oice/mail/ signature/ > *http://mail. promotions. yahoo.com/ newdomains/ sg/> Get your new Email address! Grab the Email name you've always wanted before someone else does! New Email names for you! Get the Email name you've always wanted on the new @ymail and @rocketmail. Hurry before someone else does! http://mail.promotions.yahoo.com/newdomains/sg/