Sounds as if you are designing a duplexer with coils and caps. It is often this approach will not have a high enough Q to have a notch at one freq and at the same time pass freq with low enough insertion loss.
Normally duplexers use cavities which are made from coax made from heavy metal tubes, inter and outer conductors. Not your typical coax, but follow the same format. You may have the notch on both frequencies, but what is the insertion loss at the desired pass freq. 73, ron, n9ee/r >From: sms mms <[EMAIL PROTECTED]> >Date: 2007/08/24 Fri PM 12:11:46 CDT >To: repeater <[email protected]> >Subject: [Repeater-Builder] duplexer design > >Dear all, I am Vikash Gupta from India. I am designing a duplexer having low >frequency:230 MHz, High gfreuqency: 234 MHz. I am using coil with 8 no. of >turns and 22 PF capacitor. I have to get Insertion loss <1.2 on both low and >high sides. But I have a problem in getting this. I have got Rejection of >more than 80 dB and Return loss of better than 20 dB on both sides. Please >give me suggestion what I have to do? thanks in advance. Vikash  > 5, 50, 500, 5000 - Store N number of mails in your inbox. Click here. > Ron Wright, N9EE 727-376-6575 MICRO COMPUTER CONCEPTS Owner 146.64 repeater Tampa Bay, FL No tone, all are welcome.
