4 ms. Given that the FTdx5K rise/fall is roughly double the time of the K3 -- and that the K3 at 2 ms consumes significantly less bandwidth than the FTdx5K at 4 ms, the CW transmit quality of the K3 is far superior. I would like to hear QSK on the Yaesu, compare it with the K3's QRQ mode, and note any audible artifacts in the headphones -- especially for signs of clicks and DC thumps.
Referring to the December, 2010 QST Product Review on p.45, take a look at the leading edge of the second pulse (lower trace) in Figure 1. The sharp rise and sharp edge at the top of the waveform is what is consuming the bandwidth. Based on that waveform, it was absolutely generating clicks at some distance from the Fc. That pattern is characteristic of a deficient ALC system. A deficiency in the ALC system then takes us into SSB Tx IMD. The published FTdx5K Tx IMD numbers look great with the ARRL's steady tone method but arguably, that's probably more relevant to data modes. The question is "what is the FTdx5K's ALC doing to undermine the rig's otherwise excellent SSB Tx IMD numbers, especially in Class A?" Really, the published Tx IMD figures are meaningless unless dynamic testing is conducted to simulate rapid changes in power associated with voice modes. Paul, W9AC ----- Original Message ----- From: "Jan Erik Holm" <sm2...@telia.com> To: <elecraft@mailman.qth.net> Sent: Friday, December 03, 2010 8:27 AM Subject: Re: [Elecraft] Fwd: New Sherwood report > Yes but to what rise/fall time was the radio set? AFAIK in > the FT5000 it can be changed. > > /Jim SM2EKM ______________________________________________________________ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:Elecraft@mailman.qth.net This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html
