To: Repeater-Builder From: Eric Lemmon WB6FLY While tuning up a UHF MTR2000 repeater, I became aware that the "receive" LED on my monitoring handheld radio was blinking, although the repeater was idle. On a hunch, I shut off the repeater and the blinking stopped. After thinking about it for a moment, I theorized that the transmitter's VCO was running all the time, and a very low-level signal was being emitted, but strong enough to be received in the immediate area. This exciter leakage is often seen in Micor repeaters, especially when the shields are left off by a careless technician. While wondering about what to do with this problem, I remembered that the RF Option page of the Channel Information screen (see the image below) had a "TX Idle" button and frequency window. I also remembered that the Help file said that the transmitter idle was important for simplex operation (otherwise you'll block your own receiver), and could be set the same as the transmitter frequency for repeaters (since the receiver is on a different frequency). I thought, "What if I set the transmitter idle frequency to something other than the repeater transmitter frequency?" So, I entered a TX Idle frequency that was on another channel about 50 kHz away. As soon as I wrote the codeplug back to the repeater, the low-level carrier moved to the new transmitter idle frequency. Gee, the "TX Idle" feature allows the user to set the frequency at which the exciter idles! Oddly, neither the MTR operation manual nor the service manual mentions this important application for a repeater. If the exciter leakage is a problem (or merely an annoyance) with your MTR2000, simply program a frequency in the TX Idle window that is offset from the normal TX frequency by at least 20 kHz or so. Be careful to not set it to a frequency that is an input of another repeater, or on a simplex, system, remote base or link channel. There did not seem to be any transmitter delay introduced by offsetting the exciter idle frequency. 73, Eric Lemmon WB6FLY