Long before IBOC, I had a local 5kw @ 2.5 miles distance. I could hear (distorted) sidebands to plus or minus 40 Khz. So I called up the local FCC office and asked what was allowed. Reply was we require sidebands to be -75 dB down at plus or minus 55 kHz. I'm not the best at knowing technical things, so I must ask: Can a radio with good selectivity do anything more than change clear audio to distorted sidebands? In other words, can a radio reject something that is transmitted? If some can, what type of special circuitry is required?
I know what is being done with the transmitter is a major factor. When I was 2.5 miles from the 5 kw on 1280, I was also maybe about 15 miles from WCCO-830. Some poor nights, I could weakly detect their splash up to 900 kHz. At the time there was a proposal for US to go to 9 kHz spacing, & some clears that adequately restricted their sidebands would be allowed to increase power to 750 kw. So, WCCO tested their sideband reducer, and was only about half as wide. When FCC said no to 9 kHz spacing & 750 kw, WCCO went back to as wide as it was before. 73, George S., MN ________________________________ From: Aaron Kreider <aa...@campusactivism.org> To: irca@hard-core-dx.com Sent: Sunday, June 30, 2013 12:25 AM Subject: Re: [IRCA] ? 4 ULR/DSP experts: -25kHz wide splatter in ?1k BW, , strong signal pumping? I think some IBOC stations put out dirty signals - I've got this video of WIP 610, Philadelphia putting out a signal from 570 to 650 khz. https://www.youtube.com/watch?v=maEonHy2eSA _______________________________________________ IRCA mailing list IRCA@hard-core-dx.com http://montreal.kotalampi.com/mailman/listinfo/irca Opinions expressed in messages on this mailing list are those of the original contributors and do not necessarily reflect the opinion of the IRCA, its editors, publishing staff, or officers For more information: http://www.ircaonline.org To Post a message: irca@hard-core-dx.com _______________________________________________ IRCA mailing list IRCA@hard-core-dx.com http://montreal.kotalampi.com/mailman/listinfo/irca Opinions expressed in messages on this mailing list are those of the original contributors and do not necessarily reflect the opinion of the IRCA, its editors, publishing staff, or officers For more information: http://www.ircaonline.org To Post a message: irca@hard-core-dx.com
