Hi guys, I've never seen any ham rigs, HF or VHF with the bias changed depending on modes. Not one.
FT620, FT-221, FT897D FT-450, IC-910H and I've looked at the circuits of many others: FT-200, TS-520, TS-820 and commercials, Codan, Crammond and Racal. Alan VK2ZIW On Fri, 19 Jun 2020 08:54:17 +0930, Mark Jessop wrote > Heat issues might be the case for 'shack in a box' rigs like IC-7100s, > FT-857s etc... > > However, rigs like the IC-7300, IC-7610 will quite happily sit there putting > out 100W of FSK (e.g. FT8) pretty much continuously. It helps that they have > decent cooling. Since I'm feeding in that FSK signal via an audio input, the > amp isn't biased differently... > > Can't really speak for Yaesu rigs, as I don't own any. > > 73 > Mark VK5QI > > On Fri, Jun 19, 2020 at 6:08 AM David Rowe <da...@rowetel.com> wrote: > Hello Glen, > > > Consider though, that if you are at 10dB peak to average , that is 10W > > RMS for a 100W amplifier. Utilization of the 100W PA is not good ! > > Yes, and I would like to see if we can reduce PAPR (say by 3dB as a > firsts step) using some of the tricks you mentioned. > > However I am concerned that many of the SSB PAs in Ham radios aren't > rated for high RMS powers. They are probably biassed differently for CW > of FM operation. Bit worried about generating puddles of silicon, which > I understand happened in the early days of HF DV. > > Cheers, > David > > _______________________________________________ > Freetel-codec2 mailing list > Freetel-codec2@lists.sourceforge.net > https://lists.sourceforge.net/lists/listinfo/freetel-codec2 > --------------------------------------------------- Alan Beard OpenWebMail 2.53
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