Geoffrey Mackenzie-Kennedy wrote: > > With respect Ron, as far as I know the term "Roofing Filter" was in use > many > years before up-conversion superhet receivers with a fist IF at VHF > started > to appear in the market. >
Correct Geoff. The first up-conversion ham rigs were introduced in the early 1980s (TS-930S I believe). The Japanese manufacturers got the idea that everyone wanted general coverage in their receivers, which then required up-conversion and an IF at VHF. Rob Sherwood had been marketing his 600 Hz "roofing filter" mod for the down-conversion Drake R4C several years before that, and as you said the term had already been in use many years prior. 73, Bill -- View this message in context: http://elecraft.365791.n2.nabble.com/Roofing-Filter-Usage-tp5682095p5686154.html Sent from the [K3] mailing list archive at Nabble.com. ______________________________________________________________ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:[email protected] This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html
