Ron, AC7AC wrote: "The carrier is keyed on and off sharply. That is, it rises from zero to maximum quickly at the start of each code element, then drops back to zero quickly at the end of the element." ========== Not too quickly, or clicks will result. The K2 had quite bad clicks (+/-1500 Hz) until they developed a mod to cure that problem. K2 kits now include the mod, and they are among the most click-free of rigs today, with clicks extending only about +/-200 Hz from center freq.
Icom IC-756 Pro IIs and IIIs have severe clicks extending +/-1500 Hz with the factory default risetime setting of "4 msec" (actually measured at 2 msec). Fortunately this is a user selectable menu setting and the rig's clicks are reduced to +/-400 HZ when the risetime is set to the max of "8 msec" (actually measure at 4 msec). The Yaesu MP series of rigs has been notorious for clicks extending +/-2500 Hz. The W8JI mod reduces the problem to +/-300 Hz. I understand that Yaesu fixed the problem (without fanfare) about a year ago on current production radios. The Ten-Tec Omni 6+ also has a bad click reputation (the Omni 6 non+ is click free).. In addition to fast rise/fall times (ARRL recommends a minimum of 4 msec to be click-free), the corners at the transitions should be rounded, rather than sharp. Most hams whose rigs have clicks are unaware of their problem because their casual QSOs are in relatively uncrowded bands. During contests however, when adjacent QSOs might be taking place only 500 Hz away, clicks heard outside of your receiver's passband are quite prevalent. This problem has abated somewhat in recent years because the ham community has been made aware of it via the many ham e-mail reflectors and many owners have performed click mods on their rigs. 73, de Earl, K6SE _______________________________________________ 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
