One useful resource for phasing-type rigs is the (free) Quadnet filter design program from Tonne Software.? This program calculates the component values for various orders of all pass filters (using op-amps) that approximate to wide band 90 deg phase shift networks.? The software calculates the maximum opposite sideband suppression with these networks, although to achieve that requires very careful construction and setting up.?
Richard G3OTK
On Saturday, 13 April 2019, 02:21:58 BST, John VA7JBE via Groups.Io <va7jbe@...> wrote:
Hi Alison,
I read about this a while back and have been looking for some more information on 3rd order all pass filters since then.? Unfortunately whatever I can find is a bit over my head.? Could you recommend any resources that might be a bit more accessible to the self-taught amateur?? I'm about to have some free time on my plate and I'd be interested in learning more about this.
