Ideas to share
Posted: Thu Dec 12, 2013 9:52 am
This is my first post on this group. I am looking for a long time at the scotty spectrum analyzer both as an instrument and as a nice way to improve my HF skills. I have few ideas about the scotty design I want to share with you
The first IF filter is incompatible with my "plumbing skills" and moreover he is too bulky to me.One idea can to replace it with a single Narrow band GPS filter in place of. The GPS filter I find out (http://www.epcos.com/inf/40/ds/ae/B4060.pdf) is centered at 1575MHz with a pretty good bandwitdth of 2.4Mhz. As a bonus we can have a 1500 Mhz analyzer in one band.
A relatively narrow directional coupler (http://188.8.131.52/pdfs/D19G.pdf) can be added in front of it with attenuators in between and MMIC at the end.
The first oscillator can be build around this VCO http://184.108.40.206/pdfs/ROS-3200-419+.pdf. is phase noise is a bit less good than the original but:-We can avoid the MMIC thanks to is healthy 11dBm output power, at least for the Basic and basic + TG version (the one I intend to build) -We can use a ADF4113 HV pll and so skip the OPA.
A lot to discuss so, please give feedback's !