At 07:09 PM 5/5/2004 -0700, you wrote: >If the (class C) PA isn't being driven by the exciter, the devices will be >off. In that condition, it would be rather difficult for a low-level >signal (milliwatt or less) to drive the collector of an RF power transistor >hard enough to cause mixing. Most all of your problems will be with your >TX on.
<---Class C is exactly the reason odd order IM (usually 3rd) is created. As a matter of fact, the fact that the amp is Class C is the main issue, not whether its in cutoff or not. Remember, Class C operation is inherently non-linear, which is what causes the IM in the first place. Again, with the TX on, it really isn't IM (unless some non-linear device in the RF field generates RF in response) - it's more of a more-or-less "straightforward" mixing of frequencies, not frequencies generated as a result of some non-linear device. Although it is entirely possible the RF from the 2 meter xmt is causing some external device (dissimilar metal joint in the high RF field for example) to be generating IM. In that case, it would still be a non-linear device involved. It just wouldn't be internal to the repeater. They are 2 completely different animals with completely different methods of resolution. Ken ------------------------------------------------------------------------------ President and CTO - Arcom Communications Makers of state-of-the-art repeater controllers and accessories. http://www.ah6le.net/arcom/index.html Be sure to see our products at this year's Dayton Hamvention! Repeater Builders spaces 707 through 710 AH6LE/R - IRLP Node 3000 http://www.irlp.net 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/
