To answer the question of whether the K3 is too noisy - does it have internal noise that limits its performance, I performed a simple test by turning off the agc and comparing the unclipped audio output level with a 50 ohm resistor connected to ANT2 and my multiband vertical dipole on ANT1; on 10 meters, the external noise was 17 dB greater on the vertical dipole with a greater difference on the lower frequency bands. I also checked for the presence of external noise at the mains/line frequency by inspecting the audio output with a spectrum analyzer in AM mode and didn't find any discernible harmonic series of the mains/line frequency plus I didn't find anything for the blanker to blank. The nearest above ground power line is more than a quarter mile away. While this was a rather casually performed test, it seems safe to conclude that my K3 is not noisy. So much for that non-existent problem.
6 meters, on the other hand, is not limited by external noise; perhaps that's why there's a 6 meter preamp option. I haven't adjusted the agc settings; my K3 agc response seems very flat which is what I prefer. As for not using the RF gain, that seems a rather absurd statement unless you don't care about maximizing the receive performance of the K3 under difficult conditions. One recent example that I've commented on previously is being able to blank a strong local's key clicks plus other noises while receiving weak signals with 200 Hz of his operating frequency. The K3 has a flexible set of tools but it's not a magic; if you don't want to make use of all it's capabilities, that's your choice but it's not a choice that I would make. It does seem like we've beaten this topic to death. 73, Dunc, W5DC > > >> If the receiver has a properly designed AGC system then there are >> only two variables that are potentially the operator's >> responsibility: 1) Preamp On/Off and 2) >> Attenuator On/Off. With the smarts built into modern radios, why >> can't the radio do, for example upon band switching, a little >> routine of turning each of these on and off and measuring the >> resulting SNR and then setting them accordingly? If an S9+50 dB >> neighbor suddenly pops up, the DSP should know sooner than the >> operator that the ADC is being overloaded and act accordingly. If >> an antenna is changed or a noise source pops up, a simple macro >> executed by a key tap could run the routine automatically and be >> done with it. >> >> > > ______________________________________________________________ > 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 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
