Bruce
Mark adds some clarity.? Those measurements you describe relate to 'unintended' radiation apart from the antenna connector path - yes we often experience this in our homes and workplaces.? In the uBITX we are mostly interested in what comes from the antenna connector - sometimes called conducted spurious.? As we are world-wide, we might find that other nation's requirements may be similar to those here in the US - some may be more stringent perhaps.?
As Farhan points out, the regulation is in dBc (relative power) versus the real-world phenomena relating to receiving absolute signal strength in dBm.? But the regulations may not allow our argument.? [I also asked my local fellow club members about those speed limit signs, and how often we might exceed those by just a little ... but they weren't interested in my analogy!].?
Regulations tend to be even tougher in VHF and UHF, due in part to criticality of emissions in that spectrum.?
Practically, it is good practice to work our uBITX transceivers into our own nation's requirements.? We are collectively challenged as few of us possess spectrum analyzers.? A recipe for modifications that provides a little performance margin would be nice.? We don't yet that I know of have technical consensus on the solution.? I suggest we not major on one particular board being the measure of solution as there is some variation in levels across the population.? I like adding relays for the harmonic issue as I think it should provide conservative margin - I am not sure of the best solution for 45 MHz related IF spurious.?
Curt
