Nope. I have seen them on the spectrum, and you only need 15 kc of rx, place carrier on one side. I have a R390A being rebuilt and expect it in about three weeks, it has a 16 kc filter and a low Z IF output that I will run to a separate sync detector/ amp. I had hopes for the SDR thing I bought, but have given up as a usefull receiver. noise floor is way to high, probably 20 DB above my 75A4 and the audio from AM still sounds " different" . Also a moderatly weak AM station is unreadable compared to my 75A2 and 75A4. I did feed a sine wave into the SDR and observed that the lower half is shifted, sort of leans and is tighter, the shocker was the appearance of ocassional steps in the sine wave, like the first computers years ago. Makes me wonder what it does to a complex waveform ( voice). by no means am I implying that I can hear 15 KC anymore. The SDR does make a great bandscope and I do not know what I would do without it now, was on a few days ago, about 10 AM, 3.700 + or - and was watching four other AM QSOs in that area, More AM than ssb!!!! " and I go on and on" Bernie ----- Original Message ----- From: "Jim Tonne" <[email protected]> To: "Discussion of AM Radio in the Amateur Service" <[email protected]> Sent: Friday, March 19, 2010 10:38 AM Subject: Re: [AMRadio] speakers
> > Bernie: > >> there do appear to be some SW BC that >> transmit up to about 15 KC. > > I seriously doubt that! International shortwave > regulations require a flat response to 4500 > Hz and a sharp rolloff above that. I don't know > the required degree of attenuation at 5 kc > but I think 35 dB down is an accepted standard. > > 15 kc response would require a 30 kc receiver > bandwidth - most unlikely. > > - JimT W4ENE > > > > > ______________________________________________________________ > Our Main Website: http://www.amfone.net > AMRadio mailing list > Searchable Archives: http://www.mail-archive.com/[email protected]/ > List Rules (must read!): http://w5ami.net/amradiofaq.html > List Home: http://mailman.qth.net/mailman/listinfo/amradio > Post: [email protected] > To unsubscribe, send an email to [email protected] with > the word unsubscribe in the message body. > > This list hosted by: http://www.qsl.net > Please help support this email list: http://www.qsl.net/donate.html > ______________________________________________________________ Our Main Website: http://www.amfone.net AMRadio mailing list Searchable Archives: http://www.mail-archive.com/[email protected]/ List Rules (must read!): http://w5ami.net/amradiofaq.html List Home: http://mailman.qth.net/mailman/listinfo/amradio Post: [email protected] To unsubscribe, send an email to [email protected] with the word unsubscribe in the message body. This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html
