seems you are talking about building a hub/switch for beverages. I asked several times here about commercial options and I found the RAS8x2 (too big for me) and the DXPedition II by KD9SV
Finally I have the DXP II with a splitter to share the beverages in the two radios (K3 and TS850) and is working very well 73, Jorge CX6VM/CW5W -----Mensaje original----- De: [email protected] [mailto:[email protected]] En nombre de Lee K7TJR Enviado el: Miércoles, 02 de Febrero de 2011 12:42 a.m. Para: [email protected] Asunto: Topband: Switching Beverages Pete, here is my take on switching Beverages, It is a lot harder to make a switch with very good isolation at 500 ohms than it is at 50 or 75 ohms. You need very good isolation between connections so that your 20 to 30 dB notches are not destroyed by leakage from another antenna. What you save on transformers will surely be spent on doubling up relays to get decent isolation. If you consider a relay with a few pf of feedthru capacitance, it will have a certain reactance at the operating frequency. This reactance will form a voltage divider with the switched impedance. If it is 500 ohms there will be a lot more feed through than if it was 50 or 75 ohms. What ever you do for switching, think it through and make sure you consider the isolation between antennas. Keep looking as there are some that have solved this problem before. My 2 cents worth. Lee K7TJR _______________________________________________ UR RST IS ... ... ..9 QSB QSB - hw? BK _______________________________________________ UR RST IS ... ... ..9 QSB QSB - hw? BK
