At 4/12/2010 08:34 AM, you wrote: >At 08:16 AM 04/12/10, you wrote: > >I'm making plans to link my 2-meter repeater to a 220 mhz hub > >repeater. What type of transceiver, radios, etc is best for a 220 > >link ? Thanks ! > >One big question is what's your duty cycle going to be? > >Another is what is your potential desense going to be? >Back before we lost 220-222 one system in an area that >used in-high and out-low on UHF was going to use a couple >of low end channels as inbound link frequencies until he did >the math... There was no way he could make a 250w >system near 441.750 live with a receiver near 220.800.
Why not? If the TX were 220.80 I could possibly see an unresolvable 2nd harmonic issue, but subharmonics from the 441.750 TX can always be suppressed. A long time ago we had such a problem with 1/2 the TX freq. of a UHF MVP equal to the input freq. of a 220 repeater at the same site. Had to pull the exciter out of the MVP & put it in an RF-tight box, but there were no problems after that. Bob NO6B
