I've bought optical filters from Andover. They are pretty cheap, at least compared to the rest of the industry. > http://www.andovercorp.com/Web_store/index.php On 3/31/2013 5:52 AM, Attila Kinali wrote: > > Probably. But as steep filters for optics are kind of hard to come by, > i think a super heterodyne design isn't realy going to work.