Hello Arie, Good, at least my observation is correct.
It is essential for a modern transceiver having the ability to notch a strong unwanted carrier right at the front. Upon 'notch' of the offending carrier, the 'wanted' weak signal should prominently pop out from the noise. The effect of the de-sensed AGC by the strong carrier should, by then, be greatly reduced. I would consider 'AGC off' is a solution of the last resort. A high end radio should not reply on this very last weapon. 73 Johnny VR2XMC ----- 郵件原件 ---- 寄件人﹕ Arie Kleingeld PA3A <[email protected]> 收件人﹕ [email protected] 傳送日期﹕ 2010/11/10 (三) 9:26:35 PM 主題： Re: [Elecraft] Manual notch In K3 Johnny, This is correct. Same experience here. Although I would like that the notch would take the carrier out like a conventional IF notch. It has been said several times in the reflector that taking out the carrier and increasing the gain again would degrade performance, especially the dynamic range. If I do not reproduce this right, please anyone in the group, please correct me. What I think of this? I disagree strongly. Not on the IMD thing, I cannot measure such things here anyway. I disagree because I feel the performance has already degraded. There is a great reduction in sensitivity because of something that I cannot hear (the notched carrier). Why care about dynamic range in this case? Signals must be very strong to even bring up a spurious on the noise level of the K3. Now I have something I donot hear and dont want to hear that messes up the sensitivity. There must be enough spare performance in the K3 to reduce ( I donot say eliminate) the effect of the notched carrier? Say up to the level of what the DSP filtering normally does if working with a wide roofing filter. I plee for a solution. 73 Arie PA3A Op 10-11-2010 5:18, Johnny Siu schreef: > I attempted to manual notch a strong carrier adjacent to a weak station. > Although I was able to notch out the strong carrier (from the audio), there was > no reduction in S meter level caused by that strong carrier. In other words, > the weak station did not pop out from the noise because the stronger > carrier de-sensed the K3 AGC. > > Johnny VR2XMC > ______________________________________________________________ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:[email protected] This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html ______________________________________________________________ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:[email protected] This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html
