400-512MHz, 3 Min Split, 4 Cavity Duplexer. For use with Icom IAS 100D, IAS 100W, and RFT Eclipse series repeaters. Low Price! Qty Discounts, Worldwide Shipping. Duplexer being tested after refurbishing and the addition of two more cavities to create a six-cavity set. Repeaters running more than about 40 watts commonly require higher pass/reject specs than the typical four-cavity duplexer can provide at the narrow 600 KHz Tx/Rx spacing used for 2-meter ham radio repeaters. Key Specifications: Motorola VHF 4 Cavity Duplexer Band Pass / Band Reject 136-174 MHz 250w with 1.4db loss Separation 2-10 MHz (great for land mobile or a HAM repeater with 2-3 MHz separation) 19in Rack mount ready

Cavity filters are the basic circuitry behind a Duplexer and are sharply tuned resonant circuit that allow only certain frequencies to pass. Generically, filter of this kind are known as notch filters. Physically a cavity filter is a resonator inside a conducting "box" with coupling loops at the input and output, as follows: Cavity Duplexer The AD1747-1842D335 cavity duplexer is designed for use in wireless communications systems (Band IV). It has a receive passband of 1710 to 1785 MHz and transmit passband of 1805 to 1880 MHz, passband return loss greater than 14 dB, and insertion loss of 1.2 dB or less. Ripple is 0.8 dB or less and isolation is at least 50 dB. typical four-cavity Vari-Notch duplexer system. Six and eight cavity systems are similar except for the extra filters in each channel. The photograph shown in Figure 2 is the front view of a typical four-cavity Vari-Notch duplexer. Each of the physical components in the system is labeled with the field adjustable parts shown in emboldened italics. UNPACKING