On 4/24/2011 3:37 PM, Jim Wiley wrote: > David - > > > No, the problem is not the crystal. It is the _oscillator_. The > oscillator is usually a more or less square-wave type, which is rich in > harmonics. These harmonics are then radiated by the circuitry in the > offending device, and make their way to your station. > > > The function of the crystal is to control (stabilize) the frequency on > which the oscillator operates. Color burst oscillator crystals are > used so much because they are both inexpensive and easy to use. They > are inexpensive because literally hundreds of missions of them are > manufactured. For this reason, there have been created a large > selection of IC chips that use the color burst frequency as the primary > timing function for whatever device into which they are incorporated. > Many of these chips are very simple to use, in most cases requiring no > components other a chip (manufactured specifically for the intended > function) and the crystal itself to create the desired device. > > > - Jim, KL7CC > > > > David Guernsey wrote: >> I realize it is the 4th harmonic. I do not have any problems with any >> harmonics >> of 3579 KHz except the 14316 KHz (4th harmonic). Thus, I wonder if the >> problem >> is really from the color burst crystal. >> >> 73s de Dave KJ6CBS >> >> >> > ______________________________________________________________ > Elecraft mailing list > Home: http://mailman.qth.net/mailman/listinfo/elecraft > Help: http://mailman.qth.net/mmfaq.htm > Post: mailto:[email protected] > > This list hosted by: http://www.qsl.net > Please help support this email list: http://www.qsl.net/donate.html > A square wave is rich in odd harmonics and essentially no even harmonics. So if the oscillator is putting out essentially a squared wave form, the fourth harmonic is going to be either non existent or many dB down. This thread suggests to me that the 14.316 MHz signal may be from some other source.
A bit off topic. I have a nasty 2304.150 MHz noise source that sounds digital. It comes and goes. What could it be coming from. Don, N0YE ______________________________________________________________ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:[email protected] This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html
