WA2JJH wrote: I find the TX range on CW between 15 W and a full power 100 W rig almost nil!... See if I can get 25W pep SSB out of the k2's mil spec final.
-------------- You'll need to redesign the output filters as well. They assume a certain collector impedance in the finals and that is a function of the power level and the K2's filters were designed for 10 watts. The impedance issue also affects the IMD in the finals. That's why Elecraft says not to exceed 10 watts PEP SSB even though running the power control up for as much as it'll deliver on CW is okay. Linearity isn't as important in CW. Lack of linearity will only affect the keying envelope somewhat. The difference between 10 and 100 watts is 10 dB. That's 1.5 to 3 "S" units on most receivers. The difference between 25 and 100 watts is 6 dB or 1 to 2 "S" units on most receivers. That's a big difference when signals are near the noise level or QRM is an issue. Otherwise it's not needed, as the QRP and QRPp stations demonstrate every day. SSB suffers from lower signal to noise ratios compared to CW at any power level, because the SSB signal occupies wider bandwidths. Narrower bandwidth with a given power = better S/N ratio. That's why closing down the CW filters helps pop a weak CW signal up out of the QRN. Since SSB needs 2+ kHz bandwidth for intelligible audio, the only fix to a weak signal is more power (and/or the use of some advanced filtering that doesn't restrict the bandwidth further such as the KDSP2 offers). The basic K2 SSB filter is already designed for a bandwidth of just over 2 kHz - the minimum for intelligible audio - to gain the best possible S/N ratio our of the SSB signal. Ron AC7AC _______________________________________________ Elecraft mailing list Post to: Elecraft@mailman.qth.net You must be a subscriber to post to the list. Subscriber Info (Addr. Change, sub, unsub etc.): http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/subscribers.htm Elecraft web page: http://www.elecraft.com
