OTA TV is growing rapidly which is why cable companies are hurting. I’ve been exclusively OTA for over 10 years. Also, with the repack a number of stations are being moved back to VHF.
Sent from my iPad On Feb 18, 2019, at 11:41 PM, K9MA <[email protected]> wrote: >> On Sun, Feb 17, 2019 at 4:26 PM Don Wilhelm<[email protected]> wrote: >> >> >> Low pass filters come from a past era when the FCC requirements were not >> as stringent and TVs responded to those higher order harmonics from >> amateur transmitters. That is no longer the case. > > Here, Don is talking about external low pass filters intended to suppress VHF > harmonics. If you live in an area where TV signals are weak, they may still > be necessary. Of course, hardly anyone receives their TV service that way any > more, and most TV stations have moved to the UHF bands, anyway. > > The low pass filters in solid state radios and amplifiers are necessary > because their outputs are untuned, and the nonlinearity of transistors > generates lots of harmonics, including low order ones. In the days of vacuum > tubes, the pi network served as an effective filter. The popular pi-L was > even better. > > It might be interesting, during a major contest, to listen on the second > harmonic, say around 14.120 when there's a lot of activity on 40. Many are > using solid state amplifiers now, and even 43 dB down may be audible. I've > never positively identified one, but a lot of stations don't come back to me > for other reasons, so it would be hard to tell. > > > 73, > > Scott K9MA > > -- > Scott K9MA > > [email protected] > > ______________________________________________________________ > 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 > Message delivered to [email protected] ______________________________________________________________ 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 Message delivered to [email protected]
