Digital modes are similar to any other modes whereby increasing power levels can mean the difference between no copy and solid copy. Because of the sharp line of demarcation of printing or not printing correct data, which can be only a dB or so, I guess that in that respect the digital modes are even more critical compared with other modes such as CW and SSB.
There are a number of rigs that are designed to operate with 100% duty cycle for FM and RTTY and they can operate key down at 100 watts for an extended transmission. Running them at reduced power may extend the life of the transmitter, but it may not be a significant amount. If you start transmitting with ALC action, you are probably just starting to degrade the IMD, but maybe the tradeoff is acceptable if you are right on the cusp between printing and not printing. I completely agree that we should follow Part 97 (or whatever rules your country requires) and use the lowest amount of power necessary for effective communication. There have been a few (very few) times that I even used an amplifier to increase the power beyond 100 watts in order to keep the QSO going. 73, Rick, KV9U Andrew O'Brien wrote: > > > > The replies to Ralph's question about audio levels appear to be sound > advice and certainly in keeping with what has been advised since sound > card digital modes burst upon the scene. I wonder how accurate it is > though? I have seen a few serious hams argue that "no ALC" is not > really the case, that some ALC can be OK. I have also seen mention > that the no ALC issue applies to some modes (like PSK) but not to > others like (JT65A). I also wonder about the half-power advice that > some advise. With my homebrewed interface, I could never get much > above 40 watts before some ALC began to show. When I switched to a > commerical interface with good isolation (Microkeyer by Microham) I > can almost always get 100 watts output without any ALC action. I have > not received any negative reports about my signal . If I run 100 > watts SSB for phone contacts, why would I not want to do the same for > digital modes assuming the signal was "clean" ? . Yes, I would agree > I should not run 100 watts if communication was possible with less > power, but I don't think a brief PSK CQ at 100 watts is going to do > much more harm to my finals than a 3 minute ragchew at 50 watts, phone > . Right ? > > Comments ? > > > > -- > Andy K3UK > > > > > ------------------------------------------------------------------------ > > > No virus found in this incoming message. > Checked by AVG - www.avg.com > Version: 8.5.375 / Virus Database: 270.13.13/2236 - Release Date: 07/13/09 > 17:57:00 > >
