Re: [Elecraft] Sherwood receiver test on KX3
It appears that the kx3 does not have dynamic image rejection, rather a one time calibration for image rejection. Has there been any talk of the KX3 implementing dynamic image rejection? Perhaps a future SW revision where the image rejection goes to > 90 dB. The Flex products implemented dynamic image rejection in 2009 and it is a well documented process in technical journals. tks Dennis -- View this message in context: http://elecraft.365791.n2.nabble.com/Sherwood-receiver-test-on-KX3-tp7561045p7561087.html Sent from the Elecraft mailing list archive at Nabble.com. __ 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
Re: [Elecraft] Sherwood receiver test on KX3
So if you are running an panadapter and turn on RX shift then what happens to the panadapter display? Are the frequencies shifted on the display by 8 KHz? The Sherwood data would indicate to me that using the 8 KHz shift is a good thing to do all the time if you do not have the roofing filter and since the 2 Khz dynamic range is 96 dB without the roofing filter and with 8 KHz shift on, you get great performance this way. tks Dennis -- View this message in context: http://elecraft.365791.n2.nabble.com/Sherwood-receiver-test-on-KX3-tp7561045p7561058.html Sent from the Elecraft mailing list archive at Nabble.com. __ 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
[Elecraft] Sherwood receiver test on KX3
The Sherwood test of the KX3 says this in the notes for the superscript V "At 1 kHz performance is opposite sideband rejection limited. On CW consider switching to 8-kHz IF. Note: Roofing filter disabled in this mode." I do not see anything in the manual about the 8 Khz IF mode. It is my understanding that when the roofing filter is used, which is a low pass filter, that the IF is 0 Hz. When the roofing filter is bypassed (FIL1) does this mean that the IF is shifted up to 8 KHz? What is the IF of the IQ outputs? Can someone explain this to me because I am confused. tks Dennis -- View this message in context: http://elecraft.365791.n2.nabble.com/Sherwood-receiver-test-on-KX3-tp7561045.html Sent from the Elecraft mailing list archive at Nabble.com. __ 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
Re: [Elecraft] general coverage receive on KX3
the kx3 manual describes these front end filters as follows The relay-switched low pass filters are used during both transmit and receive. A few of the filters are dedicated to one band but most cover two bands. The signal on the antenna side of the filters pass through a forward/reflected power and SWR bridge to the HF-6 meter antenna jack (BNC), or to the optional KXAT3 automatic antenna tuner. Latching relays are used to minimize power consumption. The RF band-pass filters are used for both transmit and receive. Filters are selected with low-loss CMOS RF switches. The band pass filters significantly attenuate receive signals at harmonics of the RX frequency, particularly the odd harmonics. These filters can seriously degrade SWL sensitivity at non-ham band regions. Wayne or another designer will be able to answer this question if they are watching this. Dennis -- View this message in context: http://elecraft.365791.n2.nabble.com/general-coverage-receive-on-X3-tp7559086p7559112.html Sent from the Elecraft mailing list archive at Nabble.com. __ 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
Re: [Elecraft] general coverage receive on KX3
I am not talking about the need to desense because of an IF frequency but that the front end ham band filters may still be active when doing SWL. It is my understanding that the K2 can receive SWL but its front end filters are ham band only so if you are between any ham bands the sensitivity falls off, perhaps quite a bit due to the ham band filtering. so I am really asking if the front end filters of the KX3 can change/switch to accomodate SWL across the most common range of 3-16 MHz. tks Dennis -- View this message in context: http://elecraft.365791.n2.nabble.com/general-coverage-receive-on-X3-tp7559086p7559100.html Sent from the Elecraft mailing list archive at Nabble.com. __ 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
[Elecraft] general coverage receive on X3
wiil the KX3 receive at ~8.5 MHz or ~12 MHz without diminished sensitivity? If the sensitivity is diminished, by how much? tks Dennis -- View this message in context: http://elecraft.365791.n2.nabble.com/general-coverage-receive-on-X3-tp7559086.html Sent from the Elecraft mailing list archive at Nabble.com. __ 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
