One feature in FT8 that I would love to see is a TX ratio setting similar to wspr or fst4w where 1/4 1/5 1/6 ratios can be selected allowing more cool down time with little loss in contacts made. I use those on 630m to good effect.
On Thu, 4 Feb 2021, 7:52 pm Alan Groups, <al...@alangroups.plus.com> wrote: > Keeping thermal stress on the system - rig and PSU - by turning power down > at least a bit from full output makes sense to me with these modes, whether > or not rig ratings demand it, particularly as any reduction in received > signal strength will be minor. > > More heat = more risk of failure regardless of what rig ratings might be. > The Tx output will also usually be a bit more linear and therefore cleaner. > > Alan G0TLK > > On 04/02/2021 08:47, Saku wrote: > > Hi! > > If your rig has FM and has full output power there without warnings of FM > TX period lengths the PA should handle it. > FM, or CW carrier on, are most closest to continuous tone modulated SSB. > > As Reino says AM must have smaller carrier for modulation reasons. > Reino Talarmo kirjoitti 3.2.2021 klo 23.56: > > Hi Mike, > > Please don’t mix AM at all with e.g. Q65 that are using frequency-shift > keying and don’t have any amplitude modulation. In most rigs the 25 W > versus 100 W is due to keep amplitude modulation in PA linear range. As > such it is not due to possible high temperature rise. > Your 25 W rule is on safe side for 300 s Q65 as it starts to be same as > continuous transmission in most rigs. > > 73, Reino OH3mA > > > > *From:* Black Michael via wsjt-devel [ > mailto:wsjt-devel@lists.sourceforge.net <wsjt-devel@lists.sourceforge.net>] > > *Sent:* 3. helmikuuta 2021 23:28 > *To:* wsjt-devel@lists.sourceforge.net > *Cc:* Black Michael <mdblac...@yahoo.com> <mdblac...@yahoo.com> > *Subject:* Re: [wsjt-devel] 2.4.0 RC1 - Decodes show no callsign > > > > I will add that many operators aren't aware that their rig can't do full > power on all modes. > > > > Many rigs rated at 100W can only do 25W in AM mode (100% duty cycle) -- > the manuals do show this. > > > > For those rigs I always recommend to the ops to run FT8 at 50W max to > avoid pushing the temperature on their rig's finals. > > > > So a 300 seconds Q65 would definitely be 100% duty cycle and a max of 25W > or whatever your manual says is the AM maximum power level. > > > > Mike W9MDB > > > > > > > > > > On Wednesday, February 3, 2021, 03:20:48 PM CST, Bill Somerville < > g4...@classdesign.com> wrote: > > > > > > On 03/02/2021 21:02, Edfel Rivera wrote: > > Hi: > > Please see attachment. Seems to be decoding or the functionality is > > correct. Also, what TX power could be used? As TX intervals increase, > > Could that cause damage to rig terminals? Thinking of JT65 where TX > > power < ~30watts. > > > > BTW, Thank you very much for INNOVATION. Seems like another fantastic > > mode. > > > > 73' > > > > Edfel > > KP4AJ > > Hi Edfel, > > the lines in the Single-Period Decodes window without decodes indicate > the best, but not decodable, candidate signal within the current > frequency tolerance window. They may provide indication that a station > is transmitting. > > As for Tx power, nothing new there, use whatever is needed to make the > QSO and not more. That could be 1500 W or 1 pW depending on the band, > path, and conditions. For EME and VHF weak signal modes like ionoscatter > a few hundred watts may be necessary. Like JT65 Q65 is 100% duty cycle > and the same considerations for PA current and temperature should be > observed as would be for any other 100% duty cycle mode like FM. > > 73 > Bill > G4WJS. > > > > > > _______________________________________________ > wsjt-devel mailing list > wsjt-devel@lists.sourceforge.net > https://lists.sourceforge.net/lists/listinfo/wsjt-devel > > > _______________________________________________ > wsjt-devel mailing > listwsjt-devel@lists.sourceforge.nethttps://lists.sourceforge.net/lists/listinfo/wsjt-devel > > -- > Saku > OH1KH > > > > _______________________________________________ > wsjt-devel mailing > listwsjt-devel@lists.sourceforge.nethttps://lists.sourceforge.net/lists/listinfo/wsjt-devel > > _______________________________________________ > wsjt-devel mailing list > wsjt-devel@lists.sourceforge.net > https://lists.sourceforge.net/lists/listinfo/wsjt-devel >
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