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<blockquote data-quote="Huevos" data-source="post: 702367" data-attributes="member: 301161"><p>Well first of all it depends on the power output and linearity of the transmitter. Most obvious frequencies for interference would be anything that is a multiple of 102.5 (i.e. 1.025GHz, 1.1127GHz, 1.230, keep adding 102.5 here until you get to 2GHz). Then get each of those frequencies and add the local oscillator frequency. For 1.025 that would give: 1.025 + 9.750 and 1.025 + 10.600. So for that harmonic any problems would appear on 10.775GHz and 11.625GHz. You'd need to do that for every harmonic between 1GHz and 2GHz. And that still doesn't cover non-linearity of the transmitter or mixer products within your receiver but does give the most likely frequencies where there will be problems. If you had a spectrum analyser the easiest thing would be take off the LNB and point it towards and away from the aerial and see what the trace looks like. This would give you an idea if anything nasty is being produced by that aerial.</p></blockquote><p></p>

[QUOTE="Huevos, post: 702367, member: 301161"] Well first of all it depends on the power output and linearity of the transmitter. Most obvious frequencies for interference would be anything that is a multiple of 102.5 (i.e. 1.025GHz, 1.1127GHz, 1.230, keep adding 102.5 here until you get to 2GHz). Then get each of those frequencies and add the local oscillator frequency. For 1.025 that would give: 1.025 + 9.750 and 1.025 + 10.600. So for that harmonic any problems would appear on 10.775GHz and 11.625GHz. You'd need to do that for every harmonic between 1GHz and 2GHz. And that still doesn't cover non-linearity of the transmitter or mixer products within your receiver but does give the most likely frequencies where there will be problems. If you had a spectrum analyser the easiest thing would be take off the LNB and point it towards and away from the aerial and see what the trace looks like. This would give you an idea if anything nasty is being produced by that aerial. [/QUOTE]

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