Re: 50MHz LPF?
Yes of course there is no need for the door knob capacitors for receiving, I will use standard SM types. I would say the most important issue is the easiness of construction, as the whole receiver is built from scratch with commonly available parts, in order for the amateurs to re-build the whole thing.
Another issue may be the noise, as the preamplifier that I am using has less than 1dB NF. It is 10KHz-220MHz broadband amplifier, so all I need is to attenuate the >50MHz signals in order not to pass through the amplifier, but leaving as much as possible signal of <50MHz to pass through.
1. So based on the requirements and your estimation could you say that the filter I presented you is good enough for such a system?
2. Also, looking at the photo, do I need to put the coils too far appart? To save space, could I put them closer (smaller leads)?
3. Finally, is it better to place the filter on ANTENNA-FILTER-PREAMPLIFIER or on the ANTENNA-PREAMPLIFIER-FILTER place?
Thanks a lot for your help