Dear Nate, They are TETRA & TETRAPOL systems. It seems like our Duplexer that is causing the problem, as the TETRA system bypasses the Combiner, the noise is removed.
At first, we were thinking it is the heat problem, but the system is installed in an air-condition room at 25 deg C, and the Duplexer is not heated up. Best Regards, Kent --- On Tue, 9/3/10, Nate Duehr <[email protected]> wrote: From: Nate Duehr <[email protected]> Subject: Re: [Repeater-Builder] Noise Level on a Duplexer To: [email protected] Date: Tuesday, 9 March, 2010, 6:08 AM What specific radios, and would 3 hours be enough for the radios themselves or any other components they might be heating to return to room-temperature (whatever that is where they're installed)? Nate WY0X On 3/8/2010 10:03 AM, Kent Chong wrote: Hello Everybody, Good day. We have developed a Duplexer to combine to two signals form two systems for in-building application. The Dupluxer (or combiner) has specifications of 1.7dB insertion loss and >60dB isolation. When we set up the system and power on the two systems, the combiner works fine. However, we notice that the noise level (up link) on the two systems will slowly increase, and until 3~4 days later, the noise level has increased to -80~-60dBm level. We then power down the systems for 3 hours, and power them up again. The systems work fine again. Anybody could help? Best Regards, Kent New Email addresses available on Yahoo! 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/
