Randy, Using a TX frequency of 443.000 MHz and a RX frequency of 448.000 MHz, and with a receive sensitivity of 0.35 uV, my CommShop program calculates that 100 watts of TX power requires at least 74 dB of isolation. Since a mobile (notch only) duplexer is hardly an ideal choice, I'd suggest keeping the power below 50 watts. Keep in mind that CommShop, like most similar programs, makes many assumptions that may or may not be true in your particular case. Keeping the PA from burning up due to a high duty cycle in repeater service may be more important than avoiding desense.
73, Eric Lemmon WB6FLY -----Original Message----- From: [email protected] [mailto:[email protected]] On Behalf Of wb8art Sent: Wednesday, May 27, 2009 11:11 AM To: [email protected] Subject: [Repeater-Builder] TX max power Can some one with one of those fancy programs like Comm-Shop run it and tell me the max power a Exec II on UHF ham band run with a 75 isolation mobile duplexer. Assuming that the coax and ant are a ideal setup. Randy WB8ART
