05-01-2012, 08:52 PM
Hello Al at the moment I agree, not to mention image frequency etc, what happens if the receiver under test has Osc below Fs as in some receivers on the highest band and Osc above Fs on the other bands as is often the case.
I had an idea once as regarding IF filtering, I looked at all these ideal IF response curves and they all seemed to want to achieve very steep sides with a flat top, a bit like a square wave pulse, so I started thinking as in a swept pulse arrangement, the pulse only being initated at the start of the lower end of the required IF bandwidth, it's duration would be equal to the total IF bandpass required or selected, then use this pulse to gate the IF amp, do I need locking up?
Lawrence.
I had an idea once as regarding IF filtering, I looked at all these ideal IF response curves and they all seemed to want to achieve very steep sides with a flat top, a bit like a square wave pulse, so I started thinking as in a swept pulse arrangement, the pulse only being initated at the start of the lower end of the required IF bandwidth, it's duration would be equal to the total IF bandpass required or selected, then use this pulse to gate the IF amp, do I need locking up?
Lawrence.
