OK, it's been a while since I've had to compute this, so if my question seems a bit "trivial" or elementary in nature I apologize in advance. Yes, my math is rusty. ;-)
Having said that, I'm trying to assist another ham with a desense problem he is experiencing on his 900 MHz ham-band repeater. He is experiencing about 10dB of receiver desense because of a signal centered at 904 MHz. He tells me this is verified with a Spectrum Analyzer and it is about 100 kHz wide. I take him at his word. The site he is at has no other 900 MHz at all, but it is a commercial site with other "stuff", including various government and commercial frequencies, in use. What I am trying to do is see if we can figure out whether this might be a spur, or some maybe harmonic, that is being generated as the result of a mix of other products there. Can anyone provide me with the math necessary to try to determine whether this is a harmonic, using very rudimentary figures? (For example, I want to be able to use basic freqs like 150 MHz, 450 MHz, etc, to at least get us in the ball park.) Once we get close, then we can fine-tune the freq combinations to see if it is a mix product. Or if anyone has any ideas, I'm certainly open to suggestions. Thanks, Mark - N9WYS
