Jim, I agree that the 800 MHz repeater's carrier frequency is probably too far from the 2m repeater's input to cause a problem, but there is also the possibility that the 800MHz transmitter's exciter is causing the problem. A case in point: An older 800 MHz repeater was turned on at the same site as a local 2m repeater, and immediately caused major interference. It turned out that the exciter was radiating at 1/6 of the 868 MHz carrier, since that model transmitter used a VHF exciter followed by a doubler and a tripler. The exciter leakage was just a few kHz away from the 2m input, and it severely interfered with the 2m repeater's reception. The leakage occurred because a careless tech left off one shield and did not install all of the screws in another shield. Once the 800MHz machine was properly buttoned up, the problem went away.
73, Eric Lemmon WB6FLY -----Original Message----- From: [email protected] [mailto:[EMAIL PROTECTED] On Behalf Of Jim Sent: Friday, July 27, 2007 8:34 AM To: [email protected] Subject: Re: [Repeater-Builder] Coax length between added cavity and duplexer <SNIP> Wow-an 800 repeater is giving a 2M rx problems? Must be a really crappy rx! Or the antennas are REALLY close! -- Jim Barbour WD8CHL
