Scott, Although you did not mention it, did this symptom just start recently? If so, check to see if any event (lightning, a new station startup, etc.) occurred around that time. If your station is co-located with one or more other stations, there may be leakage from one of them as a result of a frequency change or perhaps a shield plate was not put back in place.
One really insidious culprit is a CPU clock crystal in some microprocessor-controlled device that has drifted enough to cause a harmonic to be picked up by your equipment. The spurious signal does not have to be a harmonic on your input frequency; it sometimes can get into the IF chain, if the receiver is not properly shielded. If the squelch is right at the threshold, just a little site noise might trip the COR if the controller is not set up to require both COR and PL to key the transmitter. Don't rule out the possibility that the controller is malfunctioning, due to a random failure or damage. A good test is to borrow a known-good controller as a temporary substitute, and see if the problem continues. 73, Eric Lemmon WB6FLY ----- Original Message ----- From: "Scott" <[EMAIL PROTECTED]> To: <[email protected]> Sent: Saturday, April 08, 2006 5:50 PM Subject: [Repeater-Builder] Weird Kerchuking Problem > Here's the problem... > > Every so often (several times in 10 minutes) we are getting a key up > of our repeater. > > Here is what we know... > There is no signal coming in on the input frequency. No even a small > spike. It is almost like something in the set up is timing and keying, > but it is not an exact interval. Doesn't matter is RX tone is enabled > in the CAT or not. > > Here is the setup... > Motorola Mitrek trunk mount on 443.275, CAT 250 controller, Com-Spec > TS64DS tone board. It has a good 300W 3 can duplexer that is tuned > correctly and working well. 75Amp power supply. The cabinet also has > an APRS rig in it, as well as a remote receiver for another repeater, > and a link radio, but NONE of that is even turned on (and doesn't make > a difference when it is). > > Suggestions as to what to look for...? > > > > > > > > > > > Yahoo! Groups Links > > > > > > > > Yahoo! Groups Links Yahoo! Groups Links <*> To visit your group on the web, go to: http://groups.yahoo.com/group/Repeater-Builder/ <*> To unsubscribe from this group, send an email to: [EMAIL PROTECTED] <*> Your use of Yahoo! Groups is subject to: http://docs.yahoo.com/info/terms/
