Gerald, Thanks, for the explanation. I'm sure I will have a lot of fun, playing with this radio.
I hope the technical data sheet will be published soon. I want to see how to configure the transverters for use with this setup. I will want to get this up on satellite as soon as possible (v/u). Thanks, again. Michael Hasenfratz Sent from my iPad On Jun 6, 2012, at 5:11 PM, Gerald Youngblood <[email protected]> wrote: > Hi Michael, > > Several of the answers others provided are good but maybe not complete. I > could give you a long technical answer but I will try the simple ones for why > the gap in coverage. > > 1. The A/D converter works continuously over that range but there will be > images around the nyquist frequency if you don't provide adequate filtering. > Nyquist is 122.88 MHz. We need a sufficient band stop around Nyquist to > prevent images. > 2. The FM band can have extremely strong signals, which we want to attenuate > to allow wide band SCU operation. The 77 MHz cutoff was convenient to allow > 4m operation for Europe while offering attenuation in the FM band. 77 MHz is > the 3dB cutoff of the low pass filter. > 3. The 135 to 165 MHz filter offers bandwidth to cover interesting > frequencies in the 2m range while attenuating the FM band and preventing > images. > 4. The radio covers 60m in wide band mode but does not have a separate > preselector. Since no one operates 60m in a high power multi-multi contest > environment it will make no difference. I doubt that I will ever need > preselectors at my home QTH. I don't even expect to need a preamp until I > get to 10m and maybe even 6m given my local noise floor. The radio covers > ALL current and future bands from 60 KHz to 77 MHz continuously with the > exception that 100W is only available from 1.8 to 30 MHz and 50 to 54 MHz. > > Gerald > > > Hope that helps. > > Gerald > > Sent from my iPad > > On Jun 6, 2012, at 4:48 PM, Michael Hasenfratz <[email protected]> wrote: > >> Could somebody explain why the SCUs have a break in frequencies from 77 to >> 135 MHz? >> >> Also, what no 60 meters? >> >> Michael Hasenfratz >> Sent from my iPad >> _______________________________________________ >> Flexedge mailing list >> [email protected] >> http://mail.flex-radio.biz/mailman/listinfo/flexedge_flex-radio.biz >> This is the FlexRadio Systems e-mail Reflector called FlexEdge. It is used >> for posting topics related to SDR software development and experimentalist >> who are using beta versions of the software. > _______________________________________________ Flexedge mailing list [email protected] http://mail.flex-radio.biz/mailman/listinfo/flexedge_flex-radio.biz This is the FlexRadio Systems e-mail Reflector called FlexEdge. It is used for posting topics related to SDR software development and experimentalist who are using beta versions of the software.
