Interesting observations, Dan. I don't have a Norcal 40 but I have built many receivers including single conversion superhets like that.
First, for really "easy" listening, I turn the AGC off. I find that having the band noise automatically pumped up loud between signals is very tiring - sort of like living with a loud noise in the room I can't turn off. So I turn the K2 AGC off for most work and ride the RF gain control. That way signals sound natural, standing out nicely above the noise and, when the signal pauses, the noise stays down at the same level. IIRC, the Norcal 40A does not have AGC. Nor do my homebrew receivers. Secondly, I find that really sharp I.F. filters are more tiring than wider bandwidth filters. The primary reason for that is that, at narrow bandwidths, all the band noise that comes through is almost on the same frequency as the signal. In short, the noise competes with the signal like QRM, not QRN. I can often copy CW, even very weak signals, much better with a 1 kHz or wider filter than a narrower filter even though the wide filter lets more total QRN through. My brain is better able to hear the signal in the noise and pick it out if the noise isn't compressed into a narrow bandwidth. If the band is busy, it does require that you be able to copy one CW signal while hearing several at once. That's a basic skill in CW, I think, but many Hams today have never learned it, so they strive for very sharp filters that cut out all but one signal. Even so, it's hard to pay attention to the 'voice' we want to hear if some loudmouth is screaming in our ear. And, when the band if very active (e.g. a contest) that happens often as very loud signals crowd close to the weaker one we're copying. A narrow filter can subdue that "loudmouth" ;-) But, almost all the time, I prefer listening to CW with a filter in the range of 1 kHz wide. Setting up my K2 for no AGC and using wider filter bandwidths makes it just a comfy to listen to over time as any other receiver I've used. I also have a KX1 and it is a joy to listen to with its continuously variable filter and quiet rx chain. (I disabled its AGC ;-) BTW, did you know that the designer of the NORCAL 40 is Wayne Burdick N6KR, the chief designer of the Elecraft rigs? Ron AC7AC -----Original Message----- From: [email protected] [mailto:[email protected]] On Behalf Of Daniel Paul Perez Sent: Monday, December 29, 2008 9:32 PM To: [email protected] Subject: [Elecraft] [ K2 KX1 K1 ] Advice sought on Elecraft radios I was wondering if I might get some insight, perspective and counsel on Elecraft CW QRP DX radios from the group. About six years ago, I lived across the street from MIT Lincoln Laboratory and Hanscom AFB. Space was limited so I built a NorCal 40A a purchased a Hi-Q-Antennas 380 Tune A Dipole NVIS for portable use inside or on a porch. Subsequently I purchased an older non-dsp built K2 QRP #502. To the point, I'm still not all that happy with the level of noise on the K2. If I connect a miracle antenna or the hi-q-antennas between the NorCal 40A and Elecraft K2 the Norcal 40A is much less fatiguing to listen to and seems to "hear" a little better. Additionally, a couple of hams from the local clubs CWA and PART helped me set up the HI-Q-Antenna 380 TAD in September at my new home and then we tried a $5 home made 20M dipole between two trees oer a shed that was "significantly" louder on both the K2 and Norcal. The NorCal 40A and K2 are being switched back and forth in the same setting and environment. We had an MFJ antenna analyzer to test with as well - the 380 TAD tunes 1:1 beautifully and is optimized for 40M and military frequencies. It's an impressive piece of engineering. So here I am with an antenna(s) that cost more than the K2 radio, and satisfied with neither. I've sent the K2 to Elecraft's Gary Surrency twice who certifies its one of the ten best sounding and 10 best built radios he's seen. I'm using a Samlex power supply. I purchased a Cobra Ultralite Sr. with a Balun Designs balun that I hope to have in the trees in the next few weeks when the tree guy gets out from under his ice storm damage workload. Maybe this wil be a game changer? I'm thinking to go to a KX1, or K1 (build or purchase) or the Icom-703+ with 400 Inrad. Would these be quieter radios more like the 40A? I understand the 703+ and K2 are similar generation/concept designs. Why is the Norcal 40A much quieter than the K2? The radios are from the same pedigree and designer. I thought about the basic K3 but I'm not sold on the K2. Which receiver is better between the KX1, K1? I like the concept of the KX1 as I'm a functional quadriplegic in an electric wheelchair and smaller packages appeal to me. However, I also have profound hearing loss and would need ipod amplified speakers on the KX1. The K1 appeals as well, but will it be as fatiguing as the K2? Would the 703+ be quieter than all of the above as well ? How much better is the K1 or KX1 receiver than the 703+? I also have spare 28A and 60A gel cell wheelchair batteries - could I power the KX1 or K1 with these? My interest is QRP DX [CW] and in general lifelong learning about the world and environment. I have been essentially off the air for 20+ years and used to be 25-30wpm. My first rig was an Icom 735. Thanks for your advice and patience. Dan AD1P [email protected] _______________________________________________ Elecraft mailing list Post to: [email protected] 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 _______________________________________________ Elecraft mailing list Post to: [email protected] 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
